JP6464939B2 - Spectral sensitivity measuring apparatus and spectral sensitivity measuring method - Google Patents

Description

  The present invention relates to a spectral sensitivity measuring apparatus and a spectral sensitivity measuring method for measuring the absolute spectral sensitivity of a solar cell.

  A solar cell is an element that directly converts light energy into electric power by utilizing the photovoltaic effect, and various solar cells have been researched and developed, and have begun to spread widely in recent years. There are various types of solar cells such as silicon-based solar cells using silicon (Si), compound-based solar cells using a compound semiconductor such as InGaAs, and organic-based solar cells using an organic semiconductor. For organic solar cells, a PN junction solar cell that forms a PN junction using two types of organic semiconductors and obtains a photoelectromotive force by photoexcitation of electrons in the PN junction, and a photoelectromotive force by photoexcitation of electrons in an organic dye And a dye-sensitized solar cell for obtaining

  Unlike a silicon solar cell, an organic solar cell has a characteristic in which a short-circuit current does not change linearly with respect to irradiance.

  In order to evaluate the performance of the solar cell, for example, there are evaluation methods defined in IEC60904 and JIS (C8905 to C8991). As a method for evaluating the spectral sensitivity of a non-linear solar cell, there is a measurement method for measuring the absolute spectral sensitivity of a solar cell by the DSR method (differential spectral responsivity method) (see, for example, Patent Document 1 and Non-Patent Documents 1 and 2). Note that IEC is an abbreviation for International Electrotechnical Commission. JIS is an abbreviation for Japan Industrial Standards (Japanese Industrial Standards). In addition, there is a measurement method for measuring the absolute spectral sensitivity of solar cells other than the DSR method (for example, see Patent Document 2).

Absolute spectral sensitivity and related terms will be described.
(1) The absolute spectral sensitivity of a solar cell means the spectral sensitivity measured under a light source having a spectral irradiance to be measured.
(2) The short circuit current is a current that flows through the solar cell when the potential difference between the positive electrode and the negative electrode of the solar cell is 0V.
(3) The spectral sensitivity [A / W / m ² / nm] of the solar cell is obtained by dividing the short-circuit current output from the solar cell when the solar cell is irradiated with light of a specific wavelength by the irradiated energy. It is.
(4) The bias light is light (for example, white light) applied to the solar cell in order to flow a certain amount of bias current when measuring the differential spectral sensitivity.
(5) In the DSR method, each differential spectral sensitivity for each bias current is measured by sequentially changing the irradiation energy of the bias light, and the plurality of differential spectral sensitivities thus measured and the spectral irradiance distribution of the irradiation light to be obtained. Thus, the absolute spectral sensitivity of the solar cell is obtained. Details are described in Non-Patent Document 2.
(6) The differential spectral sensitivity is the rate of change of the short-circuit current due to a slight fluctuation in the spectral energy of an arbitrary wavelength in the solar cell based on each bias light. Differential spectral sensitivity measures the short-circuit current in a solar cell (short-circuit current for bias light irradiation), and measures the short-circuit current (short-circuit current for bias light and monochromatic light irradiation) in a state where the irradiation light is further irradiated with monochromatic light with minute irradiation energy. The difference between the short-circuit current for bias light irradiation and the short-circuit current for bias light and monochromatic light irradiation is obtained by dividing by the irradiation energy of monochromatic light.
(7) Monochromatic light is light of an arbitrary wavelength that irradiates the solar cell to measure differential spectral sensitivity. Usually, the energy is adjusted to be sufficiently small with respect to the bias light (white bias light).

  The nonlinear solar cell described above is light soaked before measuring the differential spectral sensitivity (see, for example, Patent Document 3). In order to measure accurate differential spectral sensitivity, the non-linear solar cell needs to be in a steady state. Light soaking is a process for irradiating a solar cell with bias light to bring the output into a steady state in order to place the solar cell in a steady state. Patent Document 4 discloses a technique related to response characteristics of a solar cell with respect to monochromatic light, and Patent Document 5 discloses a technique related to setting of bias light when measuring differential spectral sensitivity.

International Publication No. 2013/084441 Pamphlet JP 2004-281706 A JP 2013-221857 A JP 2013-234895 A International Publication No. 2015/025600 Pamphlet

“Calibration of solar cells. 1: The differential spectral responsivity method”, 1 May 1987 / Vol. 26 No. 9 Applied Optics IEC 60904-8 Edition 3

  In addition to the DSR method (that is, a method that uses a plurality of differential spectral sensitivities), there is a method that uses the spectral sensitivity of a solar cell under predetermined illumination. The following “spectral sensitivity” is meant to include both the differential spectral sensitivity and the spectral sensitivity of the solar cell under a predetermined illumination. The absolute spectral sensitivity is obtained by calculating the spectral sensitivity. The time required for this calculation is about 1 second. Therefore, the absolute spectral sensitivity measurement time is substantially the same as the spectral sensitivity measurement time (in the DSR method, a value obtained by adding a plurality of differential spectral sensitivity measurement times). Therefore, the absolute spectral sensitivity measurement time is substantially the same as the spectral sensitivity measurement time.

  The absolute spectral sensitivity measurement is premised on light soaking that stabilizes the solar cell. Therefore, in addition to the absolute spectral sensitivity measurement time, the time required for light soaking (hereinafter, light soaking time) must be considered. Generally, the fluctuation range of the short-circuit current becomes smaller as time elapses from the start of light soaking. In order to accurately measure the spectral sensitivity, it is necessary to make the fluctuation range of the short-circuit current during measurement as small as possible. However, if so, the light soaking time becomes longer.

  In the measurement of spectral sensitivity, a short-circuit current generated by irradiating a solar cell with combined light in which bias light and monochromatic light are superimposed is measured. In order to accurately measure the spectral sensitivity, it is necessary to reduce the fluctuation range of the short-circuit current as much as possible. However, by doing so, the measurement time of the spectral sensitivity becomes long.

  In the DSR method, it is necessary to perform light soaking and measure differential spectral sensitivity for each of a plurality of bias lights having different light amounts, and the measurement time of absolute spectral sensitivity is inevitably long. IEC 60904-8 Edition 3 requires the use of the DSR method for measuring the spectral sensitivity of nonlinear solar cells.

  Consider a spectral sensitivity measuring apparatus that allows a measurer to set an allowable value (in other words, an allowable error) of the fluctuation range and automatically measures absolute spectral sensitivity using the DSR method under the set allowable error condition. . Since the measurer desires an accurate absolute spectral sensitivity measurement, the tolerance tends to be set strictly. According to the present inventor, when the tolerance is set strictly, the light soaking time under each bias light becomes longer than expected or the response characteristic of the object to be measured is slower than expected. It has been found that a situation occurs in which the measurement time (= light soaking time + absolute spectral sensitivity measurement time) becomes considerably long (for example, 100 hours or one week).

  According to such a spectral sensitivity measuring apparatus, the measurer assumes that the measurement time (= light soaking time + absolute spectral sensitivity measurement time) is, for example, several hours in the measurement of the absolute spectral sensitivity by the DSR method. In reality, however, there is a possibility that the measurement time greatly exceeds the assumption of the measurer.

  The present invention provides a spectral sensitivity measuring apparatus and a spectral sensitivity measuring method capable of preventing in advance that the light soaking time and the absolute spectral sensitivity measuring time greatly exceed the assumption of the measurer in the measurement of the absolute spectral sensitivity. Objective.

The spectral sensitivity measuring apparatus according to the first aspect of the present invention that achieves the above object uses the spectral sensitivity measured by irradiating the solar cell with the combined light that is a light obtained by superimposing the bias light and the monochromatic light. A spectral sensitivity measuring device for measuring the absolute spectral sensitivity of the solar cell, the first light source unit for emitting the bias light, the second light source unit for emitting the monochromatic light, and the short-circuit current of the solar cell. Measuring the absolute spectral sensitivity of the solar cell, a current measuring unit for measuring the solar cell, a shutter unit for switching between an open state in which the solar cell is irradiated with the monochromatic light and a closed state in which the solar cell is not irradiated with the monochromatic light Before performing a preliminary measurement using the solar cell, the short-circuit current generated when the bias light is irradiated to the solar cell as a first short-circuit current, Bahia While the light is irradiated to the solar cell, the short-circuit current generated when the monochromatic light is continuously irradiated to the solar cell is a second short-circuit current, and the bias light is irradiated to the solar cell. The shutter unit is switched from a closed state to an open state, and the short-circuit current generated by irradiating the solar cell with the monochromatic light is defined as a third short-circuit current. A first information generating unit that generates first information indicating a relationship between a light soaking time during which the solar cell is irradiated with the bias light before measurement and an error of the first short-circuit current; In the process of calculating the measured value of the second short-circuit current at each of the plurality of times, the length of the accumulation time is changed for a plurality of times of accumulating the value of the short-circuit current at a predetermined accumulation time. To generate second information indicating the relationship between the number of times of averaging, which is the number of the measured values used for calculating the average of the measured values, the accumulation time, and the error of the second short-circuit current A second information generation unit that performs switching from the closed state to the open state and the third short-circuit current when the combined light is irradiated to the solar cell, A response characteristic of the third short-circuit current is measured, and the response characteristic is used to indicate a relationship between a waiting time until the third short-circuit current is stabilized and an error of the third short-circuit current. A third information generating unit for generating the information, and the spectral sensitivity measuring device further includes a first information determined by a measurer based on an error of the first short-circuit current indicated by the first information. 1 tolerance, the error of the second short-circuit current indicated by the second information is The second allowable error determined by the measurer based on the error and the third allowable error determined by the measurer based on the error of the third short-circuit current indicated by the third information are the measurement An input unit input by the user, a first setting unit for setting the first allowable error, the second allowable error, and the third allowable error input to the input unit, and the first setting A predicted value of the light soaking time is calculated based on the first tolerance set in the unit, and the absolute spectral sensitivity measurement time is calculated based on the second tolerance and the third tolerance. And a time calculation unit for calculating the predicted value.

  The preliminary measurement unit performs preliminary measurement using the solar cell before the measurement of the absolute spectral sensitivity of the solar cell is started. The time calculation unit uses the preliminary measurement result and the tolerance set by the measurer (first tolerance, second tolerance, third tolerance), the predicted value of the light soaking time, and The predicted value of the measurement time of absolute spectral sensitivity is calculated. When the first allowable error is determined, the predicted value of the light soaking time is determined from the first information.

  When the second allowable error is determined, the averaging count and the accumulation time are determined from the second information. When the third tolerance is determined, the waiting time is determined from the third information. The formula for calculating the predicted value of the measurement time of the absolute spectral sensitivity using the averaging number, the accumulation time, and the waiting time is a design matter of those skilled in the art. A large number of averaging times, a long accumulation time, and a long waiting time are factors that increase the measurement time. A small number of averaging times, a short accumulation time, and a short waiting time are factors that shorten the measurement time.

  As described above, according to the spectral sensitivity measuring apparatus according to the first aspect of the present invention, the predicted value of the light soaking time and the predicted value of the absolute spectral sensitivity measurement time are measured before the measurement of the absolute spectral sensitivity is started. , The measurer can know. Thereby, in the measurement of absolute spectral sensitivity, it can prevent beforehand that the light soaking time and the measurement time of absolute spectral sensitivity largely exceed a measurement person's assumption.

  In the above configuration, the spectral sensitivity measuring device uses the differential spectral sensitivity measured by irradiating the solar cell with the combined light by sequentially changing the light amount of the bias light with the spectral sensitivity as the differential spectral sensitivity. The absolute spectral sensitivity of the solar cell is measured, and the spectral sensitivity measuring device further includes a second setting unit configured to set a plurality of light amounts having different values for the bias light, and the plurality of light amounts. For each of the bias lights, the first information generation unit generates the first information, the second information generation unit generates the second information, and generates the third information. The unit generates the third information.

  This configuration applies the first aspect of the present invention to the measurement of absolute spectral sensitivity using the DSR method.

  In the above configuration, the spectral sensitivity measuring apparatus further includes a display unit and a display control unit that controls the display unit, and the display control unit includes the averaging count, the accumulation time, the waiting time, The predicted value of the light soaking time, the predicted value of the measurement time of the absolute spectral sensitivity, the first allowable error set in the first setting unit, the second allowable error, and the third A measurement condition screen showing the measurement conditions of the absolute spectral sensitivity including the allowable error of the display, the first setting unit, the input from the input unit, the number of averaging, the accumulation time, Change setting is made to change at least one of the waiting time, the first allowable error, the second allowable error, and the third allowable error, and the time calculation unit is configured to change the first setting unit. The first tolerance is changed to When it is determined, the predicted value of the light soaking time is recalculated, and the average number of times, the accumulation time, the waiting time, the second allowable error, and the third error are calculated in the first setting unit. When at least one of the allowable errors is changed and set, the predicted value of the measurement time of the absolute spectral sensitivity is recalculated, and the display control unit displays the measurement condition screen including the recalculated predicted value. Display on the screen.

  When the measurer changes the first tolerance by looking at the predicted value of ride soaking time included in the measurement condition screen displayed on the display unit, the time calculation unit recalculates the predicted value of light soaking time. To do. The measurer looks at the predicted value of the measurement time of the absolute spectral sensitivity included in the measurement condition screen displayed on the display unit, and determines the number of averaging times, the accumulation time, the waiting time, the second allowable error, and the third When at least one of the allowable errors is changed, the time calculation unit recalculates the predicted value of the measurement time of the absolute spectral sensitivity. The display control unit causes the display unit to display a measurement condition screen including the recalculated predicted value.

  Therefore, according to this configuration, the measurer can determine the balance between the light soaking time and the first allowable error, and the measurement time of the absolute spectral sensitivity, the second allowable error, and the third allowable error. The measurer can decide the balance.

  In the above-described configuration, the spectral sensitivity measuring apparatus further includes a determination input for the absolute spectral sensitivity measurement condition displayed on the measurement condition screen displayed on the display unit when the input unit is determined. A measurement condition storage unit that stores the measurement condition, and the spectral sensitivity measuring device is stored in the measurement condition storage unit when an instruction to measure the absolute spectral sensitivity is input to the input unit. The absolute spectral sensitivity is measured using measurement conditions.

  Since this configuration stores the measurement conditions for the determined absolute spectral sensitivity, the measurement conditions can be used repeatedly.

The spectral sensitivity measuring apparatus according to the second aspect of the present invention uses the spectral sensitivity measured by irradiating the solar cell with combined light, which is light obtained by superimposing bias light and monochromatic light. A spectral sensitivity measuring apparatus for measuring spectral sensitivity, wherein the first light source unit that emits the bias light, the second light source unit that emits the monochromatic light, and a current measurement that measures a short-circuit current of the solar cell. A chopping unit that chops the monochromatic light at a predetermined frequency, and a preliminary measurement unit that performs a preliminary measurement using the solar cell before measuring the absolute spectral sensitivity of the solar cell, The short-circuit current generated when the bias light is applied to the solar cell is defined as a first short-circuit current, and the monochromatic light is continuously applied to the solar cell while the bias light is applied to the solar cell. Be done The short-circuit current generated by the above is used as a second short-circuit current, and is generated when the solar cell is irradiated with the monochromatic light periodically chopped by the chopping unit while the bias light is irradiated on the solar cell. The short-circuit current is set as a fourth short-circuit current, and the preliminary measurement unit calculates a light soaking time for irradiating the solar cell with the bias light before measuring the spectral sensitivity, and an error of the first short-circuit current. A first information generation unit that generates first information indicating a relationship, and storing the value of the second short-circuit current in a predetermined storage time is repeated a plurality of times, and the second in each of the plurality of times For the process of calculating the measured value of the short-circuit current, the process is performed by changing the length of the accumulation time, and the number of averaging that is the number of the measured values used for calculating the average of the measured values, and the storage A second information generation unit that generates second information indicating a relationship between time and an error of the second short-circuit current, and the current measurement unit has a high frequency value in the preliminary measurement. Measuring the fourth short-circuit current when the monochromatic light is chopped at each of the plurality of frequencies constituting a frequency group arranged in order from a low value to a low value to a high value, and the preliminary measurement unit Further calculates an error of the fourth short-circuit current for the frequencies adjacent to each other in order, and generates fourth information indicating a relationship between the plurality of frequencies and the error of the fourth short-circuit current. The spectral sensitivity measuring device further includes a first allowable error determined by a measurer based on an error of the first short-circuit current indicated by the first information; The second short-circuit current indicated by information 2 The second allowable error determined by the measurer based on the error and the fourth allowable error determined by the measurer based on the error of the fourth short-circuit current indicated by the fourth information are An input unit input by the measurer, a first setting unit configured to set the first allowable error, the second allowable error, and the fourth allowable error input to the input unit, and the first A predicted value of the light soaking time is calculated based on the first allowable error set in the setting unit, and the absolute spectral sensitivity is calculated based on the second allowable error and the fourth allowable error. A time calculation unit for calculating a predicted value of the measurement time.

  The spectral sensitivity measuring apparatus according to the second aspect of the present invention is different from the spectral sensitivity measuring apparatus according to the first aspect of the present invention in that a fourth allowable error is used instead of the third allowable error. is there. The spectral sensitivity measuring apparatus according to the second aspect of the present invention is based on the premise that a short-circuit current due to monochromatic light is obtained by a lock-in amplifier in the measurement of absolute spectral sensitivity. When using a lock-in amplifier, monochromatic light is periodically chopped. If the frequency is high, the spectral sensitivity measurement time can be shortened, and if the frequency is low, the spectral sensitivity measurement time is long. The inventor has found that the error of the fourth short-circuit current differs depending on the frequency. According to the spectral sensitivity measuring device according to the second aspect of the present invention, the measurer can determine the fourth allowable error based on the frequency of chopping monochromatic light and the error of the fourth short-circuit current. Therefore, the predicted value of the measurement time of the absolute spectral sensitivity reflecting the fourth tolerance can be calculated.

  In addition, the spectral sensitivity measuring device according to the second aspect of the present invention is the same as the spectral sensitivity measuring device according to the first aspect of the present invention. It is possible to prevent in advance that the measurement time greatly exceeds the assumption of the measurer.

  In the above configuration, the spectral sensitivity measuring device uses the differential spectral sensitivity measured by irradiating the solar cell with the combined light by sequentially changing the light amount of the bias light with the spectral sensitivity as the differential spectral sensitivity. The absolute spectral sensitivity of the solar cell is measured, and the spectral sensitivity measuring device further includes a second setting unit configured to set a plurality of light amounts having different values for the bias light, and the plurality of light amounts. For each of the bias lights, the first information generation unit generates the first information, the second information generation unit generates the second information, and the fourth information generation The unit generates the fourth information.

  This configuration applies the second aspect of the present invention to the measurement of absolute spectral sensitivity using the DSR method.

  In the above configuration, the spectral sensitivity measuring device further includes a display unit and a display control unit that controls the display unit, and the display control unit includes the averaging count, the accumulation time, the frequency, A predicted value of the light soaking time, a predicted value of the measurement time of the absolute spectral sensitivity, the first allowable error set in the first setting unit, the second allowable error, and the fourth A measurement condition screen showing the measurement conditions of the absolute spectral sensitivity including an allowable error is displayed on the display unit, and the first setting unit is configured to input the averaging count, the accumulation time, and the input by the input from the input unit. A change setting is made to change at least one of a frequency, the first allowable error, the second allowable error, and the fourth allowable error, and the time calculation unit is set in the first setting unit. 1st tolerance is changed The calculated value of the light soaking time is recalculated, and the average number of times, the accumulation time, the frequency, the second allowable error, and the fourth allowable error are calculated in the first setting unit. When at least one of is changed and set, the predicted value of the measurement time of the absolute spectral sensitivity is recalculated, and the display control unit displays the measurement condition screen including the recalculated predicted value on the display unit. Display.

  According to this configuration, the measurer can determine the balance between the light soaking time and the first allowable error for the same reason as in the first aspect of the present invention, and the measurement time of the absolute spectral sensitivity, The measurer can determine the balance between the second tolerance and the fourth tolerance.

  In the above-described configuration, the spectral sensitivity measuring apparatus further includes a determination input for the absolute spectral sensitivity measurement condition displayed on the measurement condition screen displayed on the display unit when the input unit is determined. A measurement condition storage unit that stores the measurement condition, and the spectral sensitivity measuring device is stored in the measurement condition storage unit when an instruction to measure the absolute spectral sensitivity is input to the input unit. The absolute spectral sensitivity is measured using measurement conditions.

  Since this configuration stores the measurement conditions for the determined absolute spectral sensitivity, the measurement conditions can be used repeatedly.

The spectral sensitivity measurement method according to the third aspect of the present invention uses the spectral sensitivity measured by irradiating the solar cell with the combined light, which is light obtained by superimposing the bias light and the monochromatic light. A spectral sensitivity measurement method for measuring spectral sensitivity, comprising: a preliminary measurement step of performing preliminary measurement using the solar cell before measuring the absolute spectral sensitivity of the solar cell, wherein the bias light includes: The short-circuit current generated by irradiating the solar cell is a first short-circuit current, and the monochromatic light is continuously irradiated to the solar cell while the bias light is irradiated to the solar cell. the short-circuit current as a second short-circuit current, during irradiation the bias light into the solar cell, and the closed state of not irradiating the monochromatic light and opened to irradiate the monochromatic light to the solar cell in the solar cell Switch, the short-circuit current generated by said monochromatic light is irradiated to the solar cell and the third short-circuit current, the preliminary measuring step, the solar cell of the bias light before measuring the spectral sensitivity A first information generating step for generating first information indicating a relationship between a light soaking time to be irradiated and an error of the first short-circuit current; and storing the value of the second short-circuit current in a predetermined storage time. Repeating the process a plurality of times, and calculating the measurement value of the second short-circuit current at each of the plurality of times, changing the length of the accumulation time, performing the process, and calculating the average of the measurement values A second information generating step for generating second information indicating the relationship between the number of times of averaging, which is the number of the measurement values used in the measurement, the accumulation time, and the error of the second short-circuit current, and the closed state Before Using the third short-circuit current when the combined light is irradiated to the solar cell after being switched to the open state, the response characteristic of the third short-circuit current is measured from the time of the switch, A third information generating step for generating third information indicating a relationship between a waiting time until the third short-circuit current is stabilized and an error of the third short-circuit current using a response characteristic; The spectral sensitivity measurement method further includes a first allowable error determined by a measurer based on an error of the first short-circuit current indicated by the first information, and the second information indicated by the second information. The second tolerance determined by the measurer based on the error of the second short-circuit current and the third error determined by the measurer based on the error of the third short-circuit current indicated by the third information. 3 tolerances are input by the measurer, and the input Based on the setting step in which the first tolerance, the second tolerance, and the third tolerance input to the force step are set, and the first tolerance set in the setting step, A time calculation step of calculating a predicted value of the light soaking time and calculating a predicted value of the measurement time of the absolute spectral sensitivity based on the second allowable error and the third allowable error.

  The spectral sensitivity measuring method according to the third aspect of the present invention has the same effects as the spectral sensitivity measuring apparatus according to the first aspect of the present invention.

The spectral sensitivity measuring method according to the fourth aspect of the present invention uses the spectral sensitivity measured by irradiating the solar cell with the combined light, which is light obtained by superimposing the bias light and the monochromatic light. A spectral sensitivity measurement method for measuring spectral sensitivity, comprising: a preliminary measurement step of performing preliminary measurement using the solar cell before measuring the absolute spectral sensitivity of the solar cell, wherein the bias light includes: The short-circuit current generated by irradiating the solar cell is a first short-circuit current, and the monochromatic light is continuously irradiated to the solar cell while the bias light is irradiated to the solar cell. The short-circuit current generated by irradiating the solar cell with the monochromatic light periodically chopped while the short-circuit current is a second short-circuit current and the solar cell is irradiated with the bias light. A fourth short-circuit current, said preliminary measurement step comprises a light soaking time for irradiating the bias light before measuring the spectral sensitivity to the solar cell, a shows the relationship between the error of the first short-circuit current A first information generating step for generating one information, and storing the value of the second short-circuit current in a predetermined storage time a plurality of times, and the second short-circuit current at each of the plurality of times Regarding the process of calculating the measurement value, the process is performed by changing the length of the accumulation time, and the number of averages, which is the number of the measurement values used for calculating the average of the measurement value, the accumulation time, 2nd information generation step which generates the 2nd information which shows the relation with the error of 2 short circuit current, and the frequency group in which the frequency was arranged in order from a low value to a high value from a low value A plurality of said Measuring the fourth short-circuit current when chopping the monochromatic light at each of the wave numbers, calculating an error of the fourth short-circuit current for the frequencies adjacent to each other in order, A fourth information generation step of generating fourth information indicating a relationship between a frequency and an error of the fourth short-circuit current, and the spectral sensitivity measurement method is further indicated by the first information. The first allowable error determined by the measurer based on the error of the first short-circuit current, and the second determined by the measurer based on the error of the second short-circuit current indicated by the second information An input step in which a fourth allowable error determined by the measurer based on an allowable error and an error of the fourth short-circuit current indicated by the fourth information is input by the measurer; and the input Said first tolerance entered in step , Based on the setting step in which the second allowable error and the fourth allowable error are set, and the first allowable error set in the setting step, the predicted value of the light soaking time is calculated, A time calculation step of calculating a predicted value of the measurement time of the absolute spectral sensitivity based on the second allowable error and the fourth allowable error.

  The spectral sensitivity measuring method according to the fourth aspect of the present invention has the same effects as the spectral sensitivity measuring apparatus according to the second aspect of the present invention.

  According to the present invention, in the measurement of absolute spectral sensitivity, the light soaking time and the measurement time of absolute spectral sensitivity can be prevented in advance from greatly exceeding the assumption of the measurer.

It is a block diagram which shows the structure of the spectral sensitivity measuring apparatus which concerns on this embodiment. It is a graph explaining the 1st short circuit current. It is a graph explaining the 2nd short circuit current. It is a graph explaining the 3rd short circuit current. It is explanatory drawing explaining the functional block of the control part with which the spectral sensitivity measuring apparatus which concerns on this embodiment is provided. It is a flowchart explaining the setting of measurement conditions. It is a graph which shows the relationship between a 1st short circuit current and irradiance. It is a graph which shows the relationship between the time which irradiated the light to the solar cell, the 1st short circuit current (solid line), and the amount of current change per unit time (dotted line) of the 1st short circuit current. It is a graph which shows the relationship between the frequency | count of averaging and the 2nd short circuit current error according to accumulation time. It is a graph which shows Signal_norm (t) obtained by preliminary measurement 3. It is the graph which expanded the waveform of FIG. It is a flowchart explaining a preliminary measurement. It is a table | surface which shows the set 1st tolerance and the time of timer out. It is a table | surface which shows the set 2nd tolerance. It is a table | surface which shows the set 3rd tolerance. It is the 1st example of the table | surface which shows the measurement conditions containing the predicted value of light soaking time, and the predicted value of the measurement time of absolute spectral sensitivity. This is the second example. It is a flowchart explaining this measurement. It is a schematic diagram of the chopper shown in FIG. It is a graph explaining the 4th short circuit current. It is a block diagram of the preliminary measurement part of the modification 1. FIG. In modification 1, it is a table | surface which shows the measurement result of a 4th short circuit current. 10 is a table showing a result of calculating an error in Modification 1. It is a block diagram of the preliminary measurement part of the modification 2. It is a graph which shows the information obtained by the preliminary measurement 5 in the light quantity 1200W / m < ² > of white bias light. It is a graph which shows the information obtained by the preliminary measurement 5 in the light quantity 100W / m < ² > of white bias light. It is a graph which shows the information obtained by the preliminary measurement 5 in the light quantity 10W / m < ² > of white bias light. It is a graph which shows the information obtained by the preliminary measurement 5 in the light quantity 0W / m < ² > of white bias light. 10 is a table showing a result of calculating an error in Modification 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The spectral sensitivity measuring apparatus 1 according to this embodiment shown in FIG. 1 measures the absolute spectral sensitivity of the solar cell 100 using the DSR method. That is, the spectral sensitivity measuring apparatus 1 measures the difference spectral sensitivity measured by sequentially changing the light amount of the white bias light and irradiating the solar cell 100 with the combined light, which is a superposition of the white bias light and the monochromatic light. Then, the absolute spectral sensitivity of the solar cell 100 is measured from the plurality of differential spectral sensitivities. As described above, the measurement of the absolute spectral sensitivity includes a method using the spectral sensitivity of the solar cell 100 under predetermined illumination in addition to the DSR method. In the present embodiment, the DSR method will be described as an example. .

  The measurement of absolute spectral sensitivity using the spectral sensitivity measuring apparatus 1 includes the following (A) to (D).

(A) Setting of measurement conditions (B) Preliminary measurement (C) Setting of tolerance, display of predicted value of light soaking time and predicted value of measurement time of absolute spectral sensitivity (D) Main measurement (A) It is to set measurement conditions necessary for differential spectral sensitivity measurement such as setting of the light quantity of a plurality of white bias lights used for measurement, measurement wavelength range, measurement wavelength pitch, number of averaging, measurement frequency, and the like. (B) is for informing the measurer of the predicted values (in other words, approximate values) of the light soaking time and the absolute spectral sensitivity measurement time in the measurement of the absolute spectral sensitivity of the solar cell 100 before the actual measurement. The solar cell 100 is used for various measurements. (C) Based on the result of (B), the measurer sets various allowable errors, and calculates the predicted values of the light soaking time and the absolute spectral sensitivity measurement time under the set allowable errors. It is to calculate and display. (D) is to measure the absolute spectral sensitivity of the solar cell 100 under the measurement conditions set in (A) and the tolerance set in (C). (A), (B), (C), and (D) are performed in this order.

  With reference to FIG. 1, the structure of the spectral sensitivity measuring apparatus 1 which concerns on this embodiment is demonstrated. FIG. 1 is a block diagram showing the configuration of the spectral sensitivity measuring apparatus 1. The spectral sensitivity measuring apparatus 1 includes a first light source unit 2, a second light source unit 3, an irradiation unit 4, a current measurement unit 5, a control unit 6, and an operation unit 7.

  The first light source unit 2 adjusts the amount of white bias light and emits white bias light. White bias light is an example of bias light. The first light source unit 2 includes a first light emitting unit 20, a plane mirror 21, a shutter 22, an optical filter 23, and a diaphragm 24.

  The first light emitting unit 20 emits white bias light. The white bias light is light for causing a certain amount of short-circuit current to flow through the solar cell 100 to be measured. The first light emitting unit 20 is, for example, a halogen lamp or a xenon lamp.

  A plane mirror 21 is disposed in the optical path of the white bias light emitted from the first light emitting unit 20. The plane mirror 21 reflects the white bias light emitted from the first light emitting unit 20.

  A shutter 22, an optical filter 23, and a diaphragm 24 are arranged in this order on the optical path of the white bias light reflected by the plane mirror 21 by 90 degrees.

  When the shutter 22 is open, white bias light is emitted from the first light source unit 2, and when the shutter 22 is closed, light is shielded and no white bias light is emitted from the first light source unit 2. Since it takes time for the first light emitting unit 20 to emit stable white bias light, the first light emitting unit 20 is in an ON state and emits white bias light while the spectral sensitivity measuring apparatus 1 is in use. ing. When the white bias light is used, the shutter 22 is opened, and when the white bias light is not used, the shutter 22 is closed.

  In the international standard, AM1.5G (Air Mass 1.5G) is defined as reference sunlight for solar cell evaluation. The optical filter 23 converts the white bias light emitted by the first light emitting unit 20 into a white bias light spectrum (pseudo-sunlight) having a spectral spectrum that approximates the spectral spectrum of the reference sunlight defined by AM1.5G. Convert.

  The light amount of the white bias light converted into pseudo sunlight by the optical filter 23 is adjusted by the diaphragm 24. The diaphragm 24 is, for example, a luminous diaphragm that varies the aperture area.

  The white bias light that has passed through the diaphragm 24 is emitted from the first light source unit 2 to the outside, and the white bias light is incident on the irradiation unit 4.

  The second light source unit 3 emits monochromatic light. The second light source unit 3 includes a second light emitting unit 30, a slit 31, a diaphragm 32, a diffraction grating 33, a shutter 34, and a chopper 36.

  The second light emitting unit 30 emits light in a predetermined wavelength band including the wavelength of monochromatic light selected by the diffraction grating 33. The second light emitting unit 30 is, for example, a white lamp such as a xenon lamp or a halogen lamp. In the second light source unit 3, the light from the first light-emitting unit 20 and the light from the second light-emitting unit 30 intersect, but this is the reason for drawing and actually intersects. Not done.

  A slit 31, a stop 32, and a diffraction grating 33 are disposed in the optical path of the light emitted from the second light emitting unit 30. The second light source unit 3 includes a monochromator 38 including a slit 31 and a diffraction grating 33 as components. The monochromator 38 generates monochromatic light using the light emitted by the second light emitting unit 30.

  The monochromator 38 is a device that emits the light emitted from the second light emitting unit 30 by making it monochromatic light at a predetermined wavelength according to an instruction from the control unit 6. The monochromator 38 is, for example, a spectroscope that diffracts light of a predetermined wavelength band emitted from the second light emitting unit 30 with the diffraction grating 33 and extracts only a narrow range of wavelengths.

  The monochromator 38 includes, for example, an entrance slit (slit 31), a reflective diffraction grating 33, and an exit slit (not shown), and diffracts an incident light beam incident through the entrance slit by the reflective diffraction grating 33. In this apparatus, only a predetermined wavelength is extracted from the diffracted light of the incident light beam diffracted by the diffraction grating 33 by the exit slit. With such a configuration, the monochromator 38 can extract only the wavelength in a desired range by rotating the diffraction grating 33 and the like to select the wavelength of light reaching the slit position (single-color light conversion).

  The monochromator 38 is controlled by the controller 6 so as to extract a desired range of wavelengths.

  The diaphragm 32 is, for example, a chromatic diaphragm, and adjusts the amount of light that has passed through the slit 31.

  A shutter 34 and a chopper 36 are sequentially arranged on the optical path of monochromatic light emitted from the monochromator 38.

  When the shutter 34 is opened, the monochromatic light is emitted from the second light source unit 3, and when the shutter 34 is closed, the monochromatic light is not emitted from the second light source unit 3. Since it takes time for the second light emitting unit 30 to emit stable light, the second light emitting unit 30 is in an ON state and emits light during use of the spectral sensitivity measuring apparatus 1. When using monochromatic light, the shutter 34 is opened, and when not using monochromatic light, the shutter 34 is closed.

  The chopper 36 alternately turns on and off by periodically chopping the incident monochromatic light. Thereby, monochromatic light whose light quantity changes in a pulse shape is obtained. The monochromatic light is emitted to the outside from the second light source unit 3 and enters the irradiation unit 4.

  The irradiation unit 4 generates combined light (in other words, superimposed light) that is a light obtained by superimposing the white bias light emitted from the first light source unit 2 and the monochromatic light emitted from the second light source unit 3. The solar cell 100 to be measured placed on the stage 9 is irradiated.

  The irradiation unit 4 includes a half mirror 40, a light projecting lens 41, and a mask 42. The white bias light emitted from the first light source unit 2 and the monochromatic light emitted from the second light source unit 3 are overlapped by the half mirror 40, and the combined light is a light obtained by superimposing the white bias light and the monochromatic light. Is generated. The combined light is collected by the light projecting lens 41 and irradiated to the solar cell 100 through the mask 42.

  The synthesized light has a uniform brightness at the center of the cross section, but the brightness is not uniform at the periphery due to the shading characteristics of the lens. For this purpose, the solar cell 100 is irradiated with only the central portion of the combined light by the mask 42.

  The current measuring unit 5 measures the short-circuit current of the solar cell 100. The current measuring unit 5 includes a lock-in amplifier 50. The lock-in amplifier 50 detects only the short-circuit current (FIG. 18) due to the monochromatic light from the short-circuit current measured by the current measurement unit 5 in a state where the synthesized light is irradiated onto the solar cell 100 by the irradiation unit 4. The circuit has a function of amplifying the signal. The current measuring unit 5 can extract the short-circuit current due to the monochromatic light by calculation without using the lock-in amplifier 50.

  The control unit 6 controls the spectral sensitivity measuring device 1. FIG. 3 is an explanatory diagram illustrating functional blocks of the control unit 6. The control unit 6 is realized by a CPU, a RAM, a ROM, and the like, and includes, as function blocks, an emission control unit 60, a first setting unit 61, a second setting unit 62, an information generation unit 63, a display control unit 64, a preliminary measurement. Unit 65, time calculation unit 66, measurement condition storage unit 67, differential spectral sensitivity measurement unit 68, and absolute spectral sensitivity calculation unit 69. Details of these blocks will be described later.

  With reference to FIG. 1, the operation unit 7 is an input / output device for a measurer to operate the spectral sensitivity measuring apparatus 1, and includes a display unit 70 and an operation key unit 71. The display unit 70 is, for example, a touch panel type liquid crystal display. The display unit 70 displays, for example, absolute spectral sensitivity measurement conditions and measurement results. The operation key unit 71 is a keyboard including numeric keys. The measurer operates the operation key unit 71 and the touch panel of the display unit 70 to input commands, data, and the like to the spectral sensitivity measuring apparatus 1. The operation unit 7 is an example of an input unit.

  The spectral sensitivity measuring apparatus 1 according to the present embodiment is a solar to be measured in order to determine measurement conditions to be specified when differential spectral sensitivity measurement is performed by the DSR method before measuring the absolute spectral sensitivity of the solar cell 100. The characteristics of the battery 100 are measured in advance, and the estimated values of the light soaking time and the absolute spectral sensitivity measurement time in the measurement of the absolute spectral sensitivity of the solar battery 100 from this characteristic and the tolerance set by the measurer. The main feature is that the predicted values are calculated on the display unit 70.

  The first to third short-circuit currents will be described. FIG. 2A is a graph illustrating the first short-circuit current, where the vertical axis represents the first short-circuit current and the horizontal axis represents time. The first short-circuit current is a short-circuit current of the solar cell 100 generated by irradiating the solar cell 100 with only the white bias light of the white bias light and the monochromatic light.

  Both the second short-circuit current and the third short-circuit current are short-circuit currents of the solar cell 100 that are generated by irradiating the solar cell 100 with the combined light that is the light obtained by superimposing the white bias light and the monochromatic light. is there. FIG. 2B is a graph illustrating the second short-circuit current, in which the vertical axis represents the second short-circuit current and the horizontal axis represents time. The second short-circuit current is a short-circuit current of the solar cell 100 that is generated when the solar cell 100 is continuously irradiated with monochromatic light while the white bias light is irradiated on the solar cell 100.

  FIG. 2C is a graph for explaining the third short-circuit current, where the vertical axis represents the third short-circuit current and the horizontal axis represents time. The third short-circuit current is switched from the open state to the open state while the shutter 34 (FIG. 1) is open while the white bias light is applied to the solar cell 100, and from the open state to the closed state. Is a short-circuit current of the solar cell 100 generated by irradiating the solar cell 100 with.

  (A)-(D) mentioned above are demonstrated in order.

[Setting measurement conditions (wavelength range, wavelength pitch, white bias intensity)]
The setting of measurement conditions will be described with reference to FIGS. FIG. 4 is a flowchart for explaining setting of measurement conditions. The measurer operates the operation unit 7 to input the measurement wavelength range and the measurement wavelength pitch when measuring the differential spectral sensitivity to the spectral sensitivity measurement apparatus 1. In the second setting unit 62 (FIG. 3), the input measurement wavelength range and measurement wavelength pitch are set (step S1). It is assumed that the measurement wavelength range is set to 300 to 900 nm, for example, and the measurement wavelength pitch is set to 10 nm, for example.

The measurer operates the operation unit 7 to input a plurality of light amounts having different values with respect to the light amount of the white bias light (step S2). For example, assume that 1200 W / m ² , 1000 W / m ² , 300 W / m ² , 100 W / m ² , 30 W / m ² , 10 W / m ² , 3 W / m ² , and 1 W / m ² are input.

  The measurer places the solar cell 100 to be measured on the stage 9. The solar cell 100 is a non-linear solar cell such as a dye-sensitized solar cell.

  The emission control unit 60 (FIG. 3) irradiates the solar cell 100 with white bias light for each of the plurality of light amounts input in step S <b> 2, and the current measurement unit 5 applies the first short-circuit current of the solar cell 100. Measure (Step S3).

More specifically, the emission control unit 60 performs control to open the shutter 22 of the first light source unit 2 and close the shutter 34 of the second light source unit 3. Then, the emission control unit 60 controls the diaphragm 24 and the like to emit 1200 W / m ² of white bias light to the first light source unit 2. As a result, the white bias light emitted from the first light source unit 2 is irradiated to the solar cell 100 by the irradiation unit 4. In this state, the current measurement unit 5 measures the first short-circuit current output from the solar cell. Note that the emission control unit 60 may control to turn off the second light emitting unit 30 instead of the control to close the shutter 34 of the second light source unit 3.

For the remaining amount ^{(1000W / m 2, 300W /} m 2, 100W / m 2, 30W / m 2, 10W / m 2, 3W / m 2, 1W / m 2, the first short-circuit current in a similar manner Measured.

The information generation unit 63 (FIG. 3) generates information indicating the relationship between the first short-circuit current and the irradiance using the first short-circuit current measured in step S3, and the display control unit 64 Information is displayed on the display unit 70 (step S4). FIG. 5 is an example of this information, and is a graph showing the relationship between the first short-circuit current and the irradiance. The horizontal axis represents irradiance (W / m ² ), and the amount of light is replaced with irradiance. The vertical axis represents the first short-circuit current (mA). As shown by the solid line in the graph, when the irradiance increases, the first short-circuit current increases. The dotted line in the graph is the first derivative value of the first short-circuit current. The dotted line may be a second derivative of the first short-circuit current.

In the irradiance section where the first short-circuit current is non-linear (section where the dotted line graph value is not constant), it is necessary to set the irradiance finely in order to measure with high accuracy. On the other hand, in the irradiance section where the first short-circuit current is linear (section in which the dotted line graph value is constant), high-precision measurement can be performed without finely setting the irradiance. As shown by the dotted line in the graph, it is understood that the first short-circuit current is nonlinear when the irradiance (light quantity) is 200 (W / m ² ) or less.

The measurer operates the operation unit 7 with reference to the dotted line graph of FIG. 5, for example, six light quantities (1200 W / m ² , 1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W). / M ² , 30 W / m ² ). In this setting, a section of 200 to 30 W / m ^{2 in} the nonlinear region was set densely. The input light quantity is set in the second setting unit 62 (FIG. 3) (step S5). As described above, the second setting unit 62 sets a plurality of light amounts having different values for the white bias light.

As described above, in the present embodiment, the measurer sets each of a plurality of light amounts having different values based on the information on the measurement result of the first short-circuit current. On the other hand, there is a method in which a measurer sets the maximum value and the minimum value of the light amount, and the spectral sensitivity measuring device automatically sets the remaining light amount according to a predetermined rule (light amount automatic setting method). In this method, since the solar cell does not grasp the irradiance interval that is nonlinear with respect to the light amount, it is necessary to set the light amount relatively finely, and the number of light amounts to be set increases. For example, 12 of the light intensity ^{(1200W / m 2, 1000W /} m 2, 700W / m 2, 500W / m 2, 300W / m 2, 200W / m 2, 100W / m 2, 70W / m 2, 50W / m 2 , 30 W / m ² , 20 W / m ² , 10 W / m ² ). Since light soaking is performed for each light amount, and differential spectral sensitivity is measured, the absolute spectral sensitivity measurement time becomes long in the automatic light amount setting method.

  In the present embodiment, the measurer grasps the irradiance interval in which the graph shown in FIG. 5 is nonlinear, and sets a plurality of light amounts. For this reason, the optimum combination of a plurality of light amounts can be quickly found, and the number of the plurality of white bias light amounts necessary for differential spectral sensitivity measurement can be reduced.

[Preliminary measurement (light soaking characteristics, number of averaging, accumulation time, response characteristics)]
The preliminary measurement unit 65 (FIG. 3) performs preliminary measurement using the solar cell 100 before measuring the absolute spectral sensitivity of the solar cell 100. Preliminary measurements include preliminary measurements 1-3. Preliminary measurement 1 is a preliminary measurement related to light soaking. Preliminary measurement 2 is a preliminary measurement regarding the number of times of averaging and the accumulation time. Preliminary measurement 3 is a preliminary measurement related to a waiting time until the short-circuit current is stabilized when switching from white bias light to combined light.

{Preliminary measurement 1}
The first information generation unit 650 (FIG. 3) generates first information indicating the relationship between the light soaking time and the first short-circuit current error. Light soaking is to stabilize the solar cell 100 by irradiating the solar cell 100 with white bias light before measuring the differential spectral sensitivity.

  FIG. 6 is a graph showing the relationship between the time when the solar cell 100 is irradiated with light, the first short-circuit current (solid line), and the amount of current change per unit time (dotted line) of the first short-circuit current. This graph is an example of the first information obtained in the preliminary measurement 1. The horizontal axis is the elapsed time after the start of light irradiation, and the unit is hours and minutes. The left vertical axis is the value of the first short-circuit current, and the unit is mA. The vertical axis on the right is the amount of change in the first short-circuit current during one hour, and the unit is%. This is the amount of change in the first short-circuit current.

  The dotted line in the graph of FIG. 6 shows the relationship between the elapsed time from the start of light irradiation and the amount of change in the first short-circuit current. 0.0% means that the amount of fluctuation of the first short-circuit current during one hour (the error of the first short-circuit current) is zero. That is, the first short circuit current does not change at all during one hour. It can be seen that the amount of change decreases with time from the start of light irradiation (0:00). In FIG. 6, the change amount of the first short-circuit current is large until about 12 hours, but the change amount is small thereafter. If measurement is performed in a state where the solar cell 100 of the object to be measured is changed, a measurement error is caused. Therefore, in order to measure with high accuracy, light soaking for stabilizing the object to be measured is required. For example, when measurement is started without performing light soaking on the solar cell 100 having the characteristics shown in FIG. 6, an error of about 2% at maximum occurs during the measurement.

  In addition, after the preliminary measurement 1, in order to prevent the characteristic change of the measured object during measurement, the measured object is always kept in a short-circuit state.

{Preliminary measurement 2}
Preliminary measurement 2 is a preliminary measurement regarding the number of times of averaging and the accumulation time. In the spectral sensitivity measuring apparatus 1, noise inevitably occurs, and this causes an error in the second short-circuit current (SN error). By setting the averaging count and accumulation time to appropriate values, the error is reduced. The second information generator 651 (FIG. 3) accumulates and measures the value of the second short-circuit current for a predetermined accumulation time. This operation is repeated a plurality of times, and the process for calculating the measured value of the second short-circuit current at each of the plurality of times is performed by changing the length of the accumulation time and used for calculating the average of the measured values. The second information indicating the relationship between the number of times of averaging, the accumulation time, and the error of the second short-circuit current is generated. This will be described in detail below.

  FIG. 7 is a graph showing the relationship between the number of times of averaging and the error of the second short-circuit current according to the accumulation time. This graph is an example of the second information obtained in the preliminary measurement 2. There are three accumulation times, for example, 1 PLC (Power Line Cycle), 100 milliseconds, and 200 milliseconds. At 50 Hz, 1 PLC is 1/50 second (that is, 20 milliseconds). At 60 Hz, 1 PLC is 1/60 second (that is, 16.7 milliseconds).

  The graph of FIG. 7 can be obtained by the following method. The plurality of times is, for example, 30 times. The second information generation unit 651 repeats accumulating the value of the second short-circuit current (FIG. 2B) for a predetermined accumulation time 30 times. The second information generation unit 651 calculates a measured value (Signal (n)) of the second short-circuit current in the accumulation time for each of the first to 30th times.

  The second information generation unit 651 changes the number of times used for calculating the average of the measurement values, and averages the measurement values. This average is expressed by the following equation.

Signal_average (n) = ΣSignal (n) / n
Signal_average (n) is an average value of the measured values up to the nth time.

  The second information generation unit 651 normalizes Signal_average (n) using the following equation. ∞ is 30 times here.

Signal_average_norm (n) = {Signal_average (n) / Signal_average (∞)} − 1
The second information generation unit 651 calculates Signal_average_norm (n) for an accumulation time of 1 PLC, 100 milliseconds, and 200 milliseconds. As described above, the graph shown in FIG. 7 is obtained. The horizontal axis indicates the number of averaging. The vertical axis represents Signal_average_norm (n). This is an error of the average value of the second short-circuit current when the averaging number is 1 to 30 with respect to the average value of the second short-circuit current when the average number of times is 30, and the unit is %. This is an error of the second short-circuit current. As the number of times of averaging increases, the error of the second short-circuit current decreases.

{Preliminary measurement 3}
Referring to FIGS. 1 and 3, the emission control unit 60 moves the shutter 34 while measuring the short-circuit current of the solar cell 100 with the current measurement unit 5 in a state where the white bias light is applied to the solar cell 100. The current measuring unit 5 measures the short-circuit current (third short-circuit current). Preliminary measurement 3 is a preliminary measurement related to a waiting time (FIG. 8) until the third short-circuit current is stabilized when switching from white bias light to combined light. In the preliminary measurement 3, the third short-circuit current shown in FIG. 2C is used. The arrow indicates the timing for measuring the third short-circuit current.

  Referring to FIG. 1, shutter 34 is an example of a shutter unit, and switches between an open state in which monochromatic light is applied to solar cell 100 and a closed state in which monochromatic light is not applied to solar cell 100. In the open state, the synthesized light is irradiated to the solar cell 100. In the closed state, the solar cell 100 is irradiated with white bias light. The third information generation unit 652 (FIG. 3) uses the third short-circuit current when the shutter 34 is switched from the closed state to the open state and the combined light is irradiated on the solar cell 100, Generate information. The third information is information indicating the relationship between the time until the third short-circuit current is stabilized after the switching and the error of the third short-circuit current.

  Referring to FIG. 1, the emission control unit 60 (FIG. 3) sets the wavelength of monochromatic light emitted from the second light source unit 3 to a predetermined value (for example, 546 nm). The emission control unit 60 controls to open the shutter 34 when a predetermined time (for example, 0.2 seconds) elapses after the irradiation of the white bias light to the solar cell 100 is started. Thereby, the synthesized light is irradiated to the solar cell 100. The current measuring unit 5 measures the rising characteristic (Signal_rise (t)) of the third short-circuit current due to the combined light. Then, the emission control unit 60 performs control to close the shutter 34. Thereby, only the white bias light is irradiated to the solar cell 100, and the falling characteristic (Signal_fall (t)) of the monochromatic light is measured.

  The third information generation unit 652 obtains Signal (t) indicating the response characteristic of monochromatic light.

Signal (t) = Signal_rise (t) −Signal_fall (t)
The third information generation unit 652 normalizes Signal (t) by the following equation.

Signal_norm (t) = Signal (t) / Signal (∞)
Here, Signal (∞) is the last time when Signal (t) was measured. For example, when Signal_rise (t) and Signal_fall (t) are measured for 20 seconds, it is Signal (20). When the waveform of Signal (t) is disturbed, interpolation processing such as Lagrange interpolation and moving average may be performed on Signal (t) to make the waveform smooth.

FIG. 8 is a graph showing Signal_norm (t), and FIG. 9 is an enlarged graph of the waveform of FIG. As can be seen from the figure, the response characteristics of monochromatic light differ depending on the amount of white bias light. When monochromatic light is superimposed when irradiating with strong white bias light (1200 W / m ² ), the short-circuit current rises steeply, but in the state where white baice light is not irradiated (0 W), the short-circuit current gradually decreases. Increase. Thus, since the response characteristics of monochromatic light differ depending on the white bias light amount, in order to measure with high accuracy, it is necessary to measure after different waiting times after superimposing monochromatic light with the white bias light amount. This graph is an example of the third information obtained in the preliminary measurement 3.

The third information generation unit 652 generates the graph of FIG. 8 using Signal_norm (t). The horizontal axis indicates time (waiting time), and the unit is seconds. The vertical axis represents Signal_norm (t), and the unit is%. Signal_norm (t) indicates an error of the third short-circuit current. In each case, the amount of white bias light is 1200 (W / m ² ), 100 (W / m ² ), 10 (W / m ² ), and 0 (W / m ² ). In the above graph, the shutter 34 opens after 0.2 seconds.

From the response characteristic of the monochromatic light, the measurer can determine the waiting time until the third short-circuit current is stabilized when the white bias light is switched to the combined light. For example, when the measurement is performed 0.2 seconds after the shutter 34 is opened, in the case of 1200 (W / m ² ), the third short-circuit current has an error of 10% due to the influence of the response characteristic of the object to be measured. In the case of (W / m ² ), the error of the third short circuit current is about 1%. From this information, the measurer can determine the optimum waiting time for each white bias light amount.

For each of the plurality of amounts of white bias light, the first information generation unit 650 shown in FIG. 3 performs preliminary measurement 1 to generate first information (FIG. 6), and the second information generation unit 651 The preliminary measurement 2 is performed to generate the second information (FIG. 7), and the third information generator 652 performs the preliminary measurement 3 to generate the third information (FIG. 8). FIG. 10 is a flowchart explaining this. As described in step S5 of FIG. 4, as the light amount Eb_i (i: 1 to n) of the white bias light, the light amount Eb_1 (1200 W / m ² ), the light amount Eb_2 (1000 W / m ² ), and the light amount Eb_3 (200 W / m). ² ), light quantity Eb_4 (100 W / m ² ), light quantity Eb_5 (50 W / m ² ), and light quantity Eb_6 (30 W / m ² ) are set.

  Referring to FIGS. 1 and 10, the emission control unit 60 (FIG. 3) sets i = 1 (step S11). The emission control unit 60 performs control to open the shutter 22 of the first light source unit 2 and close the shutter 34 of the second light source unit 3 (step S12). Note that the emission control unit 60 may control to turn off the second light emitting unit 30 instead of the control to close the shutter 34 of the second light source unit 3.

Then, the emission control unit 60 controls the diaphragm 24 and the like, and causes the first light source unit 2 to emit white bias light having a light amount Eb_1 (1200 W / m ² ) (step S13). Thereby, the white bias light emitted from the first light source unit 2 is irradiated to the solar cell 100 by the irradiation unit 4 and the solar cell 100 is light-soaked. In this state, the first information generation unit 650 performs preliminary measurement 1 (that is, preliminary measurement related to light soaking) (step S14), and stabilizes the solar cell 100 of the object to be measured.

The emission control unit 60 opens the shutter 22 of the first light source unit 2 and the shutter 34 of the second light source unit 3 (step S15). As a result, the solar cell 100 is irradiated with the combined light obtained by superimposing the white bias light of the light amount Eb_1 (1200 W / m ² ) and the monochromatic light.

  In this state, the second information generation unit 651 performs preliminary measurement 2 (that is, preliminary measurement regarding the number of times of averaging and the accumulation time) (step S16).

  After the completion of the preliminary measurement 2, the third information generation unit 652 performs the preliminary measurement 3 (that is, the preliminary measurement related to the response characteristic of the third short-circuit current when the white bias light is switched to the combined light) (step S3). S17).

  After step S17, the emission control unit 60 determines whether i = n (step S18). Since the number of the plurality of light amounts set as described above is 6, n is 6.

When determining that i = n is not satisfied (No in step S18), the emission control unit 60 sets i = i + 1 (step S19), and returns to step S12. Here, i = 2, and through step S12, the emission control unit 60 sets the light amount Eb_2 (1000 W / m ² ) (step S13), and the first information generation unit 650 performs the preliminary measurement 1 (step) S14).

When the emission control unit 60 determines that i = n (Yes in Step S18), that is, in the light amount Eb_6 (30 W / m ² ), the third information generation unit 652 finishes the preliminary measurement 3 (Step S17). When the preliminary measurement ends.

[Setting of tolerance, display of predicted value of light soaking time and predicted value of measurement time of absolute spectral sensitivity]
As described in the preliminary measurement 1 with reference to FIGS. 1 and 3, the first information generation unit 650 performs the six light amounts (1200 W / m ² , 1000 W / m ²⁾ set in step S5 of FIG. , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ), a graph as shown in FIG. 6 is generated. Accordingly, six graphs as shown in FIG. 6 are generated. The percentage indicated by the vertical axis on the right side of FIG. 6 is the amount by which the first short-circuit current fluctuates during one hour as described in the preliminary measurement 1, and this is the error of the first short-circuit current. . For example, when the error of the first short-circuit current is 0.1%, the light soaking time for stabilizing the solar cell 100 is about 24 hours, and when it is 1%, the time is several hours. In order to measure the difference spectral sensitivity with high accuracy, it is desirable to stabilize the object to be measured, but this requires an enormous waiting time, which is not practical.

The display control unit 64 displays a graph (first information) as shown in FIG. 6 on the display unit 70 in the case of a light amount of 1200 W / m ² . The measurer looks at the graph and considers the light soaking time and the error of the first short-circuit current, and the allowable value of the error of the first short-circuit current for the light soaking with the white bias light with the light amount of 1200 W / m ^2. The first tolerance is determined. In this measurement, irradiation with white bias light is performed in order to stabilize the object to be measured until the value falls below the determined allowable value. When the measurer operates the operation unit 7 (an example of the input unit) and inputs the first allowable error, the first allowable error is set in the first setting unit 61.

  The measurer can also set a timer out time. When the first control error set in the first setting unit 61 is not reached even after a predetermined time has elapsed since the start of the white bias light irradiation, the emission control unit 60 times out and performs light soaking. Can be forcibly terminated. The measurer operates the operation unit 7 to input a timer-out time (for example, 60 minutes), whereby the timer-out time is set in the first setting unit 61. As a result, even when the object to be measured is not stable, it is possible not to wait for a long time until it becomes stable but to move to the next step after a predetermined time has elapsed.

Similarly, for the remaining light quantity (1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ), the first allowable error and the timer out time are It is set in the setting unit 61. FIG. 11 is a table showing the set first allowable error and timer-out time, and the display control unit 64 causes the display unit 70 to display this table. In FIG. 11, “irradiance” is shown instead of the amount of light.

As described in the preliminary measurement 2, the second information generation unit 651 performs the six light amounts (1200 W / m ² , 1000 W / m ² , 200 W / m ² , 100 W / m ²⁾ set in step S5 in FIG. , 50 W / m ² , 30 W / m ² ), a graph as shown in FIG. 7 is generated. Accordingly, six graphs as shown in FIG. 7 are generated. As described in the preliminary measurement 2,% indicated by the vertical axis in FIG. 7 indicates Signal_average_norm (n), which is an error of the second short-circuit current. The error of the second short circuit current is, for example, ± 1%. When the accumulation time is 1 PLC, the number of averaging is 2 times, when the accumulation time is 100 milliseconds, the number of averaging is 10 times, and when the accumulation time is 200 milliseconds, the number of averaging is 7 times. .

The display control unit 64 displays a graph (second information) as shown in FIG. 7 on the display unit 70 in the case of a light amount of 1200 W / m ² . The measurer looks at the graph and considers the number of averaging times, the accumulation time, and the error of the second short-circuit current, and the second short-circuit current for the measurement of the differential spectral sensitivity by the white bias light with the light amount of 1200 W / m ^2. A second allowable error that is an allowable value of the error is determined. When the measurer operates the operation unit 7 and inputs the second allowable error, the second allowable error is set in the first setting unit 61.

Similarly, for the remaining light amount (1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ), the second allowable error is set in the first setting unit 61 in the same manner. Is done. FIG. 12 is a table showing the set second allowable error, and the display control unit 64 causes the display unit 70 to display this table.

As described in the preliminary measurement 3, the third information generation unit 652 performs the six light amounts (1200 W / m ² , 1000 W / m ² , 200 W / m ² , 100 W / m ²⁾ set in step S5 of FIG. , 50 W / m ² , 30 W / m ² ), the graph shown in FIG. 8 is generated (third information). FIG. 8 shows the case of the light amount (1200 W / m ² , 100 W / m ² , 10 W / m ² , 0 W / m ² ), but the case of the above six light amounts is shown. As described in the preliminary measurement 3,% shown on the vertical axis in FIG. 8 indicates Signal_norm (t), which is an error of the second short-circuit current.

The measurer considers the error of the waiting time and the third short-circuit current, and the third short-circuit current error tolerance value for the measurement of the differential spectral sensitivity by the white bias light with the light amount of 1200 W / m ² is performed. Determine the tolerance. When the measurer operates the operation unit 7 and inputs the third allowable error, the third allowable error is set in the first setting unit 61.

For the remaining light amount (1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ), the third allowable error is set in the first setting unit 61 in the same manner. Is done. FIG. 13 is a table showing the set third allowable error, and the display control unit 64 causes the display unit 70 to display this table.

  As described above, the first setting unit 61 includes the first allowable error, the second allowable error determined by the measurer based on the error of the first short-circuit current indicated by the first information (FIG. 6). The second allowable error determined by the measurer based on the error of the second short-circuit current indicated by the information (FIG. 7) and the error of the third short-circuit current indicated by the third information (FIG. 8) A third allowable error determined by the measurer based on the setting is set by an input from the input unit (operation unit 7).

  When the first allowable error, the second allowable error, and the third allowable error are set, the time calculation unit 66 sets the predicted value of the light soaking time and the absolute spectral sensitivity for the solar cell 100 that has been subjected to the preliminary measurement. The predicted value of the measurement time is calculated. FIG. 14 is a table showing measurement conditions including these predicted values.

{Calculation of predicted light soaking time}
The predicted value of the light soaking time is calculated using the first information (FIG. 6) obtained in the preliminary measurement 1 and the first allowable error. The first allowable error shown in FIG. 11 is set for each of the six light quantities set in step S5 of FIG. Time calculating unit 66, the graph shown in FIG. 6 of the light amount 1200 W / ^{m 2} was obtained in the preliminary measurement 1, and, by using the first allowable error for the amount of light 1200 W / ^{m 2,} the light intensity 1200 W / ^{m 2} Find the light soaking time with white bias light. According to FIG. 6, for example, if the first tolerance is 1%, the light soaking time is 3 hours.

Since the graph shown in FIG. 6 differs according to the light amount, the measurer sets the first allowable error according to the light amount. The time calculation unit 66 similarly calculates the light soaking time for the remaining light amount (1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ). The time calculation unit 66 obtains a time T1 obtained by adding these six light soaking times. The time T1 is a predicted value of the light soaking time for the solar cell 100 to be measured.

{Calculation of predicted value of measurement time of absolute spectral sensitivity}
The absolute spectral sensitivity is obtained by calculating a plurality of differential spectral sensitivities (six differential spectral sensitivities in this embodiment). The time required for this calculation is about 1 second. Therefore, the measurement time of the absolute spectral sensitivity is almost the same as the value obtained by adding the measurement times of the plurality of differential spectral sensitivities. Therefore, the predicted value of the measurement time of the absolute spectral sensitivity is almost the same as the value obtained by adding the predicted values of the measurement time of the plurality of differential spectral sensitivities.

  The measurement time of the difference spectral sensitivity includes the second information (FIG. 7) and second tolerance obtained in the preliminary measurement 2, and the third information (FIG. 8) and third obtained in the preliminary measurement 3. Is calculated using the allowable error. This will be described in detail below.

The second allowable error shown in FIG. 12 is set for each of the six light quantities set in step S5 of FIG. Time calculating unit 66, the graph shown in Figure 7 for light intensity 1200 W / ^{m 2} obtained by the preliminary measurement 2, and, by using the second error margin for the amount of light 1200 W / ^{m 2,} the light intensity 1200 W / ^{m 2} When the differential spectral sensitivity is measured with white bias light, the set averaging number and accumulation time are obtained. This is the number of times of averaging and the accumulation time corresponding to “1200 W / m ² ” in FIG.

Time calculating unit 66, the graph shown in Figure 8 for the light intensity 1200 W / ^{m 2} was obtained in the preliminary measurement 3, and, using the third error margin for the amount of light 1200 W / ^{m 2,} the light intensity 1200 W / ^{m 2} When measuring the differential spectral sensitivity with white bias light, a set waiting time is obtained. This is the waiting time corresponding to “1200 W / m ² ” in FIG.

The time calculation unit 66 uses the number of averaging, the accumulation time, and the waiting time set in correspondence with the light amount 1200 W / m ² obtained as described above to calculate the difference spectral sensitivity at the light amount 1200 W / m ² . A predicted value of the measurement time (that is, the time when differential spectral sensitivity is measured with white bias light with a light amount of 1200 W / m ² ) is calculated.

Since the graphs shown in FIGS. 7 and 8 differ according to the amount of light, the measurer sets the second allowable error and the third allowable error according to the amount of light. The time calculation unit 66 similarly performs the difference with respect to the remaining light amount (1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ) at the light amount 1000 W / m ^2. Predicted value of spectral sensitivity measurement time, predicted value of differential spectral sensitivity measurement time at light quantity of 200 W / m ² , predicted value of differential spectral sensitivity measurement time at light quantity of 100 W / m ² , estimated light intensity of 50 W / m ² A predicted value of the measurement time of the difference spectral sensitivity and a predicted value of the measurement time of the difference spectral sensitivity at the light amount of 30 W / m ² are calculated. Various formulas are conceivable as formulas for calculating these predicted values, and this is a design matter for those skilled in the art. A large number of averaging times, a long accumulation time, and a long waiting time are factors that increase the predicted value. The fact that the number of averaging times is small, the accumulation time is short, and the waiting time is short are factors that shorten the predicted value.

  The time calculation unit 66 obtains a time T2 obtained by adding the predicted values of the measurement times of these six differential spectral sensitivities. The time T2 is a predicted value of the absolute spectral sensitivity measurement time for the solar cell 100 to be measured.

  The display control unit 64 causes the display unit 70 to display a measurement condition screen (not shown) including the table shown in FIG.

  The predicted value of the measurement time of the absolute spectral sensitivity is 8 hours, and the measurer operates the operation unit 7 to shorten the measurement time, for example, as shown in FIG. When loosened, the spectral sensitivity measuring apparatus 1 recalculates the waiting time, and recalculates the predicted value of the measurement time of the absolute spectral sensitivity based on the corrected waiting time. Since the third tolerance is relaxed, the predicted value of the measurement time is shorter than that shown in FIG.

  Similarly, when the measurer changes the second tolerance, the spectral sensitivity measuring apparatus 1 recalculates the predicted value of the measurement time of the absolute spectral sensitivity based on the changed value, and the display control unit 64. Causes the display unit 70 to display the recalculated predicted value of the measurement time.

  Further, when the measurer changes the first tolerance, the spectral sensitivity measuring apparatus 1 recalculates the predicted value of the light soaking time based on the changed value, and the display control unit 64 recalculates. The predicted time value is displayed on the display unit 70.

  The measurement condition storage unit 67 (FIG. 3) is used by the measurer for the measurement condition of the absolute spectral sensitivity shown on the measurement condition screen (not shown) displayed on the display unit 70. ) Memorize measurement conditions when input is made by confirming. More specifically, when a measurement person operates the operation unit 7 and inputs a confirmation in a state where the measurement condition screen including the table shown in FIG. 14 is displayed on the display unit 70, the measurement condition screen is displayed. The measurement conditions of absolute spectral sensitivity are stored in the measurement condition storage unit 67. Similarly, when the measurement condition screen including the table shown in FIG. 15 is displayed on the display unit 70, the measurement conditions of the absolute spectral sensitivity shown on the measurement condition screen are stored in the measurement condition storage unit 67. Since the determined absolute spectral sensitivity measurement condition is stored, this measurement condition can be used repeatedly.

[Main measurement]
FIG. 16 is a flowchart for explaining this measurement. 1 and 16, the measurer operates the operation unit 7 (an example of an input unit) and inputs a command for measuring the absolute spectral sensitivity. Thereby, the spectral sensitivity measuring apparatus 1 is set in the measurement condition stored in the measurement condition storage unit 67 (FIG. 3) described above and the second setting unit 62 described in [Setting of measurement condition]. Start measurement of absolute spectral sensitivity using various settings.

  First, the emission control unit 60 sets i = 1 (step S21). The emission control unit 60 performs control to open the shutter 22 of the first light source unit 2 and close the shutter 34 of the second light source unit 3 (step S22).

Then, the emission control unit 60 controls the diaphragm 24 and the like, and causes the first light source unit 2 to emit white bias light having a light amount Eb_1 (1200 W / m ² ) (step S23). Thereby, the white bias light emitted from the first light source unit 2 is irradiated to the solar cell 100 by the irradiation unit 4 to perform light soaking of the solar cell 100 (step S24).

  When the light soaking is completed, the spectral sensitivity measuring apparatus 1 measures the differential spectral sensitivity while changing the wavelength of the monochromatic light under the measurement conditions set in the preliminary measurement (step S26).

The current measuring unit 5 extracts the short-circuit current due to the monochromatic light by calculation from the second short-circuit current (FIG. 2B). The differential spectral sensitivity measuring unit 68 (FIG. 3) measures the differential spectral sensitivity at the light amount Eb_1 (1200 W / m ² ) using a short-circuit current by monochromatic light. Note that the lock-in amplifier 50 may extract a short-circuit current due to monochromatic light from the second short-circuit current. In the spectral sensitivity measuring apparatus 1, these two methods can be selected.

  After step S26, the emission control unit 60 determines whether i = n (step S27). Since the number of the plurality of light amounts set as described above is 6, n is 6.

When determining that i = n is not satisfied (No in step S27), the emission control unit 60 sets i = i + 1 (step S28), and returns to step S22. Here, i = 2, and through step S22, the emission control unit 60 causes the first light source unit 2 to emit white bias light having a light amount Eb_2 (1000 W / m ² ) (step S23). Then, the process of step S24 is performed.

When the emission control unit 60 determines that i = n (Yes in Step S27), that is, when the measurement in Step S26 is completed for the light amount Eb_6 (30 W / m ² ), the absolute spectral sensitivity calculation unit 69 (FIG. 3). ) Calculates the absolute spectral sensitivity of the solar cell 100 using a plurality (six) of the differential spectral sensitivities measured by the differential spectral sensitivity measuring unit 68 (step S29). The above is the description of this measurement.

  The main effects of this embodiment will be described. 1 and 3, preliminary measurement unit 65 performs preliminary measurement using solar cell 100 before the measurement of absolute spectral sensitivity of solar cell 100 is started. The time calculation unit 66 uses the preliminary measurement result and the tolerance set by the measurer (first tolerance, second tolerance, and third tolerance) to estimate the light soaking time, And the predicted value of the measurement time of absolute spectral sensitivity is calculated. When the first allowable error is determined, the predicted value of the light soaking time is determined from the first information (FIG. 6).

  When the second tolerance is determined, the number of times of averaging and the accumulation time are determined from the second information (FIG. 7). When the third tolerance is determined, the waiting time is determined from the third information (FIG. 8). The formula for calculating the predicted value of the measurement time of the absolute spectral sensitivity using the averaging number, the accumulation time, and the waiting time is a design matter of those skilled in the art.

  As described above, according to the spectral sensitivity measuring apparatus 1 according to the present embodiment, before the measurement of the absolute spectral sensitivity using the DSR method is started, the predicted value of the light soaking time and the measurement of the absolute spectral sensitivity are measured. Since the measurer can know the predicted value of time, the light soaking time and the measurement time of the absolute spectral sensitivity can be prevented in advance from greatly exceeding the measurer's assumption.

  As described in FIGS. 14 and 15, the measurer looks at the predicted value of the measurement time of the absolute spectral sensitivity included in the measurement condition screen (not shown) displayed on the display unit 70, and measures the absolute spectral sensitivity. When the conditions (number of averaging, accumulation time, waiting time, second allowable error, third allowable error) are changed, the time calculation unit 66 recalculates the predicted value of the measurement time of the absolute spectral sensitivity. The display control unit 64 causes the display unit 70 to display a measurement condition screen including the recalculated absolute spectral sensitivity measurement time predicted value. The same applies to the predicted value of the light soaking time.

  Therefore, according to the present embodiment, the measurer can determine the balance between the predicted value of the absolute spectral sensitivity measurement time and the allowable error (second allowable error, third allowable error). Further, the measurer can determine the balance between the predicted value of the light soaking time and the first allowable error.

  In the present embodiment, the measurement of the current value using monochromatic light has been described by the method of measuring the short-circuit current after a certain waiting time has elapsed since the shutter 34 was opened. Modifications 1 and 2 of this embodiment will be described. Modifications 1 and 2 are based on the premise that a short-circuit current due to monochromatic light is obtained by the lock-in amplifier 50 (FIG. 1) in the measurement of differential spectral sensitivity.

  The first modification will be described. FIG. 17 is a schematic diagram of the chopper 36 (FIG. 1). The chopper 36 has a function of a chopping unit that chops monochromatic light at a predetermined frequency. FIG. 18 is a graph illustrating the fourth short-circuit current, where the vertical axis represents the fourth short-circuit current and the horizontal axis represents time. Similar to the second short-circuit current (FIG. 2B) and the third short-circuit current (FIG. 2C), the fourth short-circuit current is a composite light that is a light obtained by superimposing white bias light and monochromatic light. It is a short circuit current of the solar cell 100 produced by being irradiated. The fourth short-circuit current is a short-circuit current of the solar cell 100 that is generated when the solar cell 100 is irradiated with monochromatic light periodically chopped by the chopper 36 while the white bias light is irradiated on the solar cell 100. 1 and 18, when the lock-in amplifier 50 is used, the chopper 36 is rotated to periodically chop monochromatic light. As a result, the monochromatic light constituting the combined light becomes monochromatic light whose amount of light changes periodically (in other words, pulsed monochromatic light).

  Preliminary measurement 4 regarding the frequency at which monochromatic light is chopped is defined as preliminary measurement 4. In the first modification, the preliminary measurement 4 is performed instead of the preliminary measurement 3. FIG. 19 is a block diagram of the preliminary measurement unit 65a of the first modification. The preliminary measurement unit 65a is different from the preliminary measurement unit 65 shown in FIG. 3 in that a fourth information generation unit 653 that performs the preliminary measurement 4 is provided instead of the third information generation unit 652.

  The preliminary measurement 4 will be described. The measurer determines, for example, the following frequency group as a frequency candidate for chopping monochromatic light.

Frequency group: 100Hz, 30Hz, 10Hz, 3Hz, 1Hz, 0.5Hz, 0.3Hz, 0.1Hz
This is a group of frequencies arranged in order from a high value to a low value. A group of frequencies arranged in order from a low value to a high value may be used. The current measuring unit 5 measures the fourth short-circuit current for each frequency constituting the frequency group under a predetermined amount of white bias light. Here, the predetermined light amount is set to, for example, 1000 W / m ² , 100 W / m ² , and 10 W / m ² . The reason for using three light quantities is to simplify the explanation. Actually, the predetermined light amount is the six light amounts (1200 W / m ² , 1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m set in step S5 in FIG. ² ).

FIG. 20 is a table showing measurement results of the fourth short-circuit current. Irradiance (W / m ² ) is shown instead of the amount of light. The fourth information generation unit 653 calculates the error of the fourth short-circuit current for frequencies that are adjacent in order. For example, when the irradiance (light quantity) is 1000 W / m ² , the difference between the second short-circuit current (177 mA) at 100 Hz and the fourth short-circuit current (201 mA) at 30 Hz, the fourth short-circuit at 30 Hz. Difference between current (201 mA) and fourth short-circuit current (206 mA) at 10 Hz Difference between fourth short-circuit current (206 mA) at 10 Hz and fourth short-circuit current (206 mA) at 3 Hz The difference between the fourth short-circuit current (206 mA) and the fourth short-circuit current (206 mA) at 1 Hz and the fourth short-circuit current (206 mA) at 1 Hz and the fourth short-circuit current (205 mA) at 0.5 Hz Difference between the fourth short-circuit current (205 mA) at 0.5 Hz and the fourth short-circuit current (204 mA) at 0.3 Hz, and the fourth short-circuit current (204 mA) at 0.3 Hz and 0. 4th short circuit current at 1 Hz ( 198 mA).

  Let the difference be Signal_nor (Bias, f). The difference was calculated using the following formula:

Signal_nor (Bias, f) = {Signal (Bias, f-1) / Signal (Bias, f)}-1
When Signal (Bias, f) is, for example, a fourth short-circuit current (177 mA) with a light amount of 1000 W / m ² and a frequency of 100 Hz, Signal (Bias, f−1) has a light amount of 1000 W / m ² , A fourth short-circuit current (201 mA) with a frequency of 30 Hz as a condition.

FIG. 21 is a table showing the results of calculating the difference. This table is an example of the fourth information. Referring to FIGS. 1 and 3, display control unit 64 causes display 70 to display a screen including the table shown in FIG. 21. The measurer looks at the error of the fourth short-circuit current indicated by the fourth information, and determines this allowable error (fourth allowable error) to be, for example, ± 1%. When the measurer operates the operation unit 7 and inputs the fourth allowable error, the fourth information generation unit 653 (FIG. 19) refers to the table shown in FIG. The frequency when the light quantity is 1000 W / m ² is searched for, for example, 3 Hz, the frequency when the light quantity is 100 W / m ² , for example, the frequency when the light quantity is 1 Hz and the light quantity is 10 W / m ² , for example, 0. 5 Hz is determined. In the first setting unit 61, the determined frequency and the fourth allowable error are set.

In FIG. 20 and FIG. 21, the light quantity is set to 1000 W / m ² , 100 W / m ² , and 10 W / m ² in order to simplify the explanation. Actually, it is the six light quantities (1200 W / m ² , 1000 W / m ² , 200 W / m ² , 100 W / m ² , 50 W / m ² , 30 W / m ² ) set in step S5 of FIG.

  The calculation method of the predicted value of the measurement time of the absolute spectral sensitivity is as described above. In the first modification, the preliminary measurement 4 is performed instead of the preliminary measurement 3. For this reason, in the above-described {calculation of predicted value of measurement time of absolute spectral sensitivity}, the predicted value of measurement time of differential spectral sensitivity is the second information and the second allowable error obtained in preliminary measurement 2, and , Using the fourth information obtained in the preliminary measurement 4 and the fourth tolerance.

That is, the time calculation unit 66 uses the averaging count, accumulation time, and frequency set in correspondence with the light amount 1200 W / m ² obtained as described above, and the differential spectral sensitivity at the light amount 1200 W / m ^2. Calculate the predicted value of the measurement time. Similarly, the predicted value of the difference spectral sensitivity measurement time at a light quantity of 1000 W / m ² , the predicted value of the difference spectral sensitivity measurement time at a light quantity of 200 W / m ² , and the measurement of the difference spectral sensitivity at a light quantity of 100 W / m ² A predicted value of time, a predicted value of measurement time of differential spectral sensitivity at a light quantity of 50 W / m ² , and a predicted value of measurement time of differential spectral sensitivity at a light quantity of 30 W / m ² are calculated. Various formulas are conceivable as formulas for calculating the predicted values of these measurement times, and this is a design matter for those skilled in the art. A large number of averaging times, a long accumulation time, and a low frequency are factors that increase the predicted value of the measurement time. The fact that the number of times of averaging is small, the accumulation time is short, and the frequency is high causes the predicted value of the measurement time to be short.

  The points where the first modification differs from the present embodiment are as described above. For the measurement condition screen, the change setting in the first setting unit 61, the recalculation of the predicted value of the measurement time of the absolute spectral sensitivity, etc., the third information is replaced with the fourth information with respect to the contents described in this embodiment. The third allowable error may be read as the fourth allowable error, and the waiting time may be read as the frequency.

  The main effect of the modification 1 is demonstrated. When the lock-in amplifier 50 shown in FIG. 1 is used, monochromatic light is periodically chopped. If the frequency is high, the difference spectral sensitivity measurement time can be shortened, and if the frequency is low, the difference spectral sensitivity measurement time is lengthened. The inventor has found that the difference in the fourth short-circuit current differs depending on the frequency. According to the first modification, the measurer can determine the fourth allowable error based on the difference between the frequency for chopping monochromatic light and the fourth short-circuit current when the frequency is changed. Thereby, the predicted value of the measurement time of the absolute spectral sensitivity reflecting the fourth allowable error can be calculated.

  Next, Modification 2 will be described. FIG. 22 is a block diagram of the preliminary measurement unit 65b of the second modification. In the second modification, the spectral sensitivity measuring apparatus 1 includes a preliminary calculation unit 654 instead of the third information generation unit 652 using the monochrome response characteristic (Signal_norm (t)) obtained in step S17 of FIG. The calculation unit performs a calculation represented by the following equation.

The preliminary calculation unit 654 performs convolution integration of sin (ωt) on Signal_norm (t) while changing the frequency ω, and obtains a value obtained by dividing the integral value of sin (ωt). FIG. 23A shows a 2/1 / 0.5 Hz sine wave (dotted line) with respect to the response characteristic (solid line) of Signal_norm (t) when the white bias light quantity is 1200 W / m ² . Similarly, FIGS. 23B to 23D show sine waves having different irradiance from Signal_norm (t) of 100 W / m ² , 10 W / m ² , and 0 W / m ² .

FIG. 24 shows the relationship between each irradiance and frequency calculated by the preliminary calculation unit 654. When the measurer sets an allowable error, for example, 1%, a frequency that is 1% or less is selected from the higher frequency for each irradiance from the table of FIG. For Figure 24, the irradiance 1200 W / ^{m 2,} 2 Hz, the irradiance 100W / ^{m 2,} 2 Hz, the irradiance 10 W / ^{m 2,} 2 Hz, the irradiance 0 W / ^{m 2,} selects the 0.5 Hz. The frequency of the lock-in amplifier 50 selected for each irradiance is stored in the measurement condition storage unit 67 (FIG. 3).

  The method for calculating the predicted value of the measurement time of the absolute spectral sensitivity obtained from the above result is the same as that of the first modification.

1 Spectral Sensitivity Measuring Device 7 Operation Unit (Example of Input Unit)
34 Shutter (an example of a shutter part)
36 Chopper (an example of a chopping section)
PV solar cell

Claims (7)

A spectral sensitivity measuring device that measures the absolute spectral sensitivity of the solar cell using the spectral sensitivity measured by irradiating the solar cell with the combined light that is a superimposed light of bias light and monochromatic light,
A first light source unit that emits the bias light;
A second light source unit that emits the monochromatic light;
A current measuring unit for measuring a short-circuit current of the solar cell;
A shutter unit that switches between an open state in which the solar cell is irradiated with the monochromatic light and a closed state in which the solar cell is not irradiated with the monochromatic light;
Before measuring the absolute spectral sensitivity of the solar cell, using the solar cell, comprising a preliminary measurement unit that performs a preliminary measurement,
The short-circuit current generated by irradiating the solar cell with the bias light is a first short-circuit current,
While the bias light is radiated to the solar cell, the short-circuit current generated when the monochromatic light is continuously irradiated to the solar cell is defined as a second short-circuit current,
During the irradiation of the bias light to the solar cell, the shutter unit is switched from the closed state to the open state, and the short-circuit current generated by irradiating the solar cell with the monochromatic light is changed to a third short-circuit current. age,
The preliminary measurement unit includes:
A first information generation unit that generates first information indicating a relationship between a light soaking time during which the solar cell is irradiated with the bias light before measuring the spectral sensitivity and an error of the first short-circuit current; ,
For the process of repeatedly storing the value of the second short-circuit current at a predetermined storage time a plurality of times and calculating the measurement value of the second short-circuit current at each of the plurality of times, the length of the storage time The second processing showing the relationship between the averaging number, which is the number of the measurement values used for calculating the average of the measurement values, the accumulation time, and the error of the second short-circuit current. A second information generation unit for generating information;
Using the third short-circuit current when the solar cell is irradiated with the combined light after being switched from the closed state to the open state, the response characteristic of the third short-circuit current from the time of the switching. And third information for generating third information indicating a relationship between a waiting time until the third short-circuit current is stabilized and an error of the third short-circuit current using the response characteristic. A generator,
The spectral sensitivity measuring device further includes:
Based on the first allowable error determined by the measurer based on the error of the first short-circuit current indicated by the first information, and the error of the second short-circuit current indicated by the second information The second allowable error determined by the measurer and the third allowable error determined by the measurer based on the error of the third short-circuit current indicated by the third information are input by the measurer. An input unit,
A first setting unit in which the first tolerance, the second tolerance, and the third tolerance input to the input unit are set;
A predicted value of the light soaking time is calculated based on the first allowable error set in the first setting unit, and the absolute value is calculated based on the second allowable error and the third allowable error. A spectral sensitivity measurement apparatus comprising: a time calculation unit that calculates a predicted value of a spectral sensitivity measurement time. The spectral sensitivity measurement device uses the differential spectral sensitivity measured by irradiating the solar cell with the combined light by sequentially changing the light amount of the bias light using the spectral sensitivity as the differential spectral sensitivity. Measuring the absolute spectral sensitivity of the battery,
The spectral sensitivity measuring apparatus further includes a second setting unit configured to set a plurality of light amounts having different values for the bias light,
For each of the plurality of light amounts of the bias light, the first information generation unit generates the first information, the second information generation unit generates the second information, and The spectral sensitivity measuring apparatus according to claim 1, wherein the information generating unit 3 generates the third information. The spectral sensitivity measuring device further includes:
A display unit;
A display control unit for controlling the display unit,
The display control unit is set to the averaging number, the accumulation time, the waiting time, the predicted value of the light soaking time, the predicted value of the measurement time of the absolute spectral sensitivity, and the first setting unit. Displaying a measurement condition screen showing measurement conditions of the absolute spectral sensitivity including the first tolerance, the second tolerance, and the third tolerance on the display unit;
The first setting unit receives the average number of times, the accumulation time, the waiting time, the first allowable error, the second allowable error, and the third allowable value based on an input from the input unit. Change setting to change at least one of the errors,
When the first allowable error is changed and set in the first setting unit, the time calculating unit recalculates the predicted value of the light soaking time, and the averaging time in the first setting unit. When at least one of the accumulation time, the waiting time, the second allowable error, and the third allowable error is changed and set, the predicted value of the measurement time of the absolute spectral sensitivity is recalculated,
The spectral sensitivity measuring apparatus according to claim 1, wherein the display control unit displays the measurement condition screen including the recalculated predicted value on the display unit. The spectral sensitivity measuring device further includes the measurement condition when an input to be confirmed is input to the input unit with respect to the measurement condition of the absolute spectral sensitivity displayed on the measurement condition screen displayed on the display unit. A measurement condition storage unit for storing
The spectral sensitivity measuring apparatus measures the absolute spectral sensitivity using the measurement conditions stored in the measurement condition storage unit when a command for measuring the absolute spectral sensitivity is input to the input unit. Item 4. The spectral sensitivity measuring device according to Item 3. A spectral sensitivity measuring device that measures the absolute spectral sensitivity of the solar cell using the spectral sensitivity measured by irradiating the solar cell with the combined light that is a superimposed light of bias light and monochromatic light,
A first light source unit that emits the bias light;
A second light source unit that emits the monochromatic light;
A current measuring unit for measuring a short-circuit current of the solar cell;
A chopping unit for chopping the monochromatic light at a predetermined frequency;
Before measuring the absolute spectral sensitivity of the solar cell, using the solar cell, comprising a preliminary measurement unit that performs a preliminary measurement,
The short-circuit current generated by irradiating the solar cell with the bias light is a first short-circuit current,
While the bias light is radiated to the solar cell, the short-circuit current generated when the monochromatic light is continuously irradiated to the solar cell is defined as a second short-circuit current,
The short-circuit current generated by irradiating the solar cell with the monochromatic light periodically chopped by the chopping unit while the bias light is applied to the solar cell is a fourth short-circuit current,
The preliminary measurement unit includes:
A first information generation unit that generates first information indicating a relationship between a light soaking time during which the solar cell is irradiated with the bias light before measuring the spectral sensitivity and an error of the first short-circuit current; ,
For the process of repeatedly storing the value of the second short-circuit current at a predetermined storage time a plurality of times and calculating the measurement value of the second short-circuit current at each of the plurality of times, the length of the storage time The second processing showing the relationship between the averaging number, which is the number of the measurement values used for calculating the average of the measurement values, the accumulation time, and the error of the second short-circuit current. A second information generation unit for generating information,
In the preliminary measurement, the current measurement unit chopped the monochromatic light at each of a plurality of frequencies constituting a frequency group in which the frequency is arranged in order from a high value to a low value or from a low value to a high value. Measuring the fourth short circuit current when
The preliminary measurement unit further calculates an error of the fourth short-circuit current for the frequencies that are adjacent in the order, and shows a relationship between a plurality of the frequencies and an error of the fourth short-circuit current. A fourth information generation unit for generating information;
The spectral sensitivity measuring device further includes:
Based on the first allowable error determined by the measurer based on the error of the first short-circuit current indicated by the first information, and the error of the second short-circuit current indicated by the second information The second allowable error determined by the measurer and the fourth allowable error determined by the measurer based on the error of the fourth short-circuit current indicated by the fourth information are input by the measurer. An input unit,
A first setting unit in which the first tolerance, the second tolerance, and the fourth tolerance input to the input unit are set;
Based on the first allowable error set in the first setting unit, a predicted value of the light soaking time is calculated, and based on the second allowable error and the fourth allowable error, the absolute error is calculated. A spectral sensitivity measurement apparatus comprising: a time calculation unit that calculates a predicted value of a spectral sensitivity measurement time. Spectral sensitivity measurement method for measuring the absolute spectral sensitivity of the solar cell, using the spectral sensitivity measured by irradiating the solar cell with the combined light that is a superimposed light of bias light and monochromatic light,
Before measuring the absolute spectral sensitivity of the solar cell, using the solar cell, comprising a preliminary measurement step of performing a preliminary measurement,
The short-circuit current generated by irradiating the solar cell with the bias light is a first short-circuit current,
While the bias light is radiated to the solar cell, the short-circuit current generated when the monochromatic light is continuously irradiated to the solar cell is defined as a second short-circuit current,
During irradiation the bias light is the solar cell, switch between a closed state which does not irradiate an open state for irradiating the monochromatic light to the solar cell wherein the monochromatic light to the solar cell, the monochromatic light the solar cell The short-circuit current generated by irradiation is a third short-circuit current,
The preliminary measurement step includes:
A first information generating step for generating first information indicating a relationship between a light soaking time for irradiating the solar cell with the bias light before measuring the spectral sensitivity and an error of the first short-circuit current; ,
For the process of repeatedly storing the value of the second short-circuit current at a predetermined storage time a plurality of times and calculating the measurement value of the second short-circuit current at each of the plurality of times, the length of the storage time The second processing showing the relationship between the averaging number, which is the number of the measurement values used for calculating the average of the measurement values, the accumulation time, and the error of the second short-circuit current. A second information generating step for generating information;
Using the third short-circuit current when the solar cell is irradiated with the combined light after being switched from the closed state to the open state, the response characteristic of the third short-circuit current from the time of the switching. And third information for generating third information indicating a relationship between a waiting time until the third short-circuit current is stabilized and an error of the third short-circuit current using the response characteristic. A generating step,
The spectral sensitivity measurement method further includes:
Based on the first allowable error determined by the measurer based on the error of the first short-circuit current indicated by the first information, and the error of the second short-circuit current indicated by the second information The second allowable error determined by the measurer and the third allowable error determined by the measurer based on the error of the third short-circuit current indicated by the third information are input by the measurer. Input step, and
A setting step in which the first tolerance, the second tolerance, and the third tolerance input to the input step are set;
A predicted value of the light soaking time is calculated based on the first tolerance set in the setting step, and the absolute spectral sensitivity is calculated based on the second tolerance and the third tolerance. A spectral sensitivity measurement method comprising: a time calculation step of calculating a predicted value of measurement time. Spectral sensitivity measurement method for measuring the absolute spectral sensitivity of the solar cell, using the spectral sensitivity measured by irradiating the solar cell with the combined light that is a superimposed light of bias light and monochromatic light,
Before measuring the absolute spectral sensitivity of the solar cell, using the solar cell, comprising a preliminary measurement step of performing a preliminary measurement,
The short-circuit current generated by irradiating the solar cell with the bias light is a first short-circuit current,
While the bias light is radiated to the solar cell, the short-circuit current generated when the monochromatic light is continuously irradiated to the solar cell is defined as a second short-circuit current,
The short-circuit current generated when the solar cell is irradiated with the monochromatic light periodically chopped while the bias light is applied to the solar cell is a fourth short-circuit current,
The preliminary measurement step includes:
A first information generating step for generating first information indicating a relationship between a light soaking time for irradiating the solar cell with the bias light before measuring the spectral sensitivity and an error of the first short-circuit current; ,
For the process of repeatedly storing the value of the second short-circuit current at a predetermined storage time a plurality of times and calculating the measurement value of the second short-circuit current at each of the plurality of times, the length of the storage time The second processing showing the relationship between the averaging number, which is the number of the measurement values used for calculating the average of the measurement values, the accumulation time, and the error of the second short-circuit current. A second information generating step for generating information;
The fourth short-circuit current when the monochromatic light is chopped is measured at each of the plurality of frequencies constituting the frequency group in which the frequency is sequentially arranged from a high value to a low value or from a low value to a high value. An error of the fourth short-circuit current is calculated for the frequencies adjacent to each other in the order, and fourth information indicating a relationship between the plurality of frequencies and the error of the fourth short-circuit current is generated. A fourth information generation step,
The spectral sensitivity measurement method further includes:
Based on the first allowable error determined by the measurer based on the error of the first short-circuit current indicated by the first information, and the error of the second short-circuit current indicated by the second information The second allowable error determined by the measurer and the fourth allowable error determined by the measurer based on the error of the fourth short-circuit current indicated by the fourth information are input by the measurer. Input step, and
A setting step in which the first tolerance, the second tolerance, and the fourth tolerance input in the input step are set;
Based on the first allowable error set in the setting step, a predicted value of the light soaking time is calculated, and based on the second allowable error and the fourth allowable error, the absolute spectral sensitivity is calculated. A spectral sensitivity measurement method comprising: a time calculation step of calculating a predicted value of measurement time.

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