JP5840871B2 - ELECTROLUMINESCENCE ELEMENT LIGHT EMITTING CONTROLLER AND METHOD - Google Patents

Description

  The present invention relates to an electroluminescence element and a method for manufacturing the same, and more particularly to a light emission controller and method for an electroluminescence element suitable for practical use as a light source in an infrared region.

  In recent years, electroluminescence elements (hereinafter referred to as EL elements) have attracted attention as lightweight and thin surface-emitting elements. This EL element is an element utilizing the principle that a fluorescent substance emits light by recombination energy between holes injected from an anode and electrons injected from a cathode when an electric field is applied. The EL element is mainly used as a light emitting element of a display of various devices such as a mobile device.

  These EL elements include a dispersion type EL element in which phosphor particles are dispersed in a binder made of an organic polymer material to form a light emitting layer, and a thin film type EL element in which an insulating layer is provided on both sides or one side of a thin film light emitting layer. However, most of them are made of inorganic semiconductors such as GaAs and GaN. In these inorganic semiconductors, In is added to efficiently emit light and to adjust the emission wavelength. In order to obtain such an inorganic semiconductor, an expensive crystal growth apparatus is required, and a rare material such as In, which is much more expensive than a silicon element, is used as an additive. For this reason, conventionally, if a large number of EL elements are manufactured, the resources of the rare material are wasted correspondingly, which causes a problem of resource depletion.

  Therefore, in recent years, an organic EL element using an organic compound as a light emitting material has become widespread (for example, see Patent Document 1). However, this organic EL device has many problems to be solved, such as a short lifetime of an organic compound used as a light emitting material. In a field where high output and high reliability are required, an inorganic semiconductor rather than an organic EL device is required. It can be said that it is desirable to use as a luminescent material. In fact, when an EL element using this inorganic semiconductor as a light emitting material is used for optical communication, it can be said that it is more desirable to emit near infrared light with little light loss.

Japanese Patent Laid-Open No. 10-036829

T. Kawazoe, K. Kobayashi, S. Takubo, and M. Ohtsu, J. Chem. Phys., Vol.122, No.2, January 2005, pp.024715 1-5

  Silicon is an inorganic semiconductor having a band gap in the near infrared. However, silicon is an indirect semiconductor and is not desirable as a near infrared EL element. In particular, in recent years, EL devices using porous silicon obtained by microcrystallizing silicon have been proposed. However, their luminous efficiency is also less than 1%. For this reason, a technique capable of improving the light emission efficiency in the near infrared in an EL element using silicon as a light emitting material has been desired. Similarly, GaP which is an inorganic semiconductor compound is used in the wavelength region of 550 nm. However, since GaP is an indirect semiconductor as well as silicon, the luminous efficiency as an EL element is about 0.1%.

  For this reason, conventionally, there has been a need to improve the light emission efficiency in an EL element using an indirect semiconductor such as silicon as a light emitting material. In addition to this, a module for efficiently controlling the light emission of the EL element is required. However, in the past, this has not been devised.

  Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to provide electroluminescence capable of efficiently performing light emission control of an electroluminescence element exhibiting excellent light emission efficiency. An object of the present invention is to provide a light emission controller and method for an element.

In order to solve the above-described problems, a light emission controller for an electroluminescence element according to the present invention is a light emission controller for an electroluminescence element including a semiconductor layer including a p layer and an n layer, by applying a forward bias voltage. A diffusion current is generated at the junction between the p layer and the n layer, and the surface shape and / or dopant distribution of one or more of the layers is changed based on Joule heat generated by the generated diffusion current. Repeatedly, the inversion distribution is generated in the conduction band and the valence band by the forward bias voltage, and the inversion distribution is formed at the place where the near-field light is generated based on the surface shape and / or the dopant distribution after the change. The diffusion current can be reduced by stimulated emission of electrons in the conduction band in multiple stages based on a non-adiabatic process. By reducing the Joule heat, the surface shape and / or dopant distribution is fixed, and the forward bias voltage is turned on / off for the electroluminescent element that emits light by the stimulated emission and the electroluminescent element. the first driving circuit freely, with respect to the electroluminescent element, and a ON / OFF freely second driving circuit said first driving circuit smaller forward bias voltage, said first driving circuit And by turning on the forward bias voltage application by the second drive circuit , the current flowing with respect to the increase in voltage is increased to cause the electroluminescence element to emit light, and then after reaching the breakover voltage, the first bias is applied . voltage by turning OFF the forward bias voltage applied by the drive circuit Increasing the current flowing in accordance with the reduction, by further turning OFF the forward bias voltage is applied by the second driving circuit, and wherein the extinguishing the electroluminescent device.

The electroluminescence element emission control method according to the present invention is an electroluminescence element emission control method including a semiconductor layer including a p layer and an n layer. By applying a forward bias voltage, the p layer and the n layer are applied. Repeatedly generating a diffusion current at the junction of the layers and changing the surface shape and / or dopant distribution of any one or more of the layers based on Joule heat generated by the generated diffusion current, and the forward direction The conduction band that forms the inversion distribution at the location where the inversion distribution is generated in the conduction band and the valence band by the bias voltage, and the near-field light is generated based on the surface shape and / or the dopant distribution after the change. The diffusion current is reduced by the induced emission of electrons in multiple stages based on a non-adiabatic process. By lowering the surface shape and / or the dopant profile with fixing, a first driving circuit freely ON / OFF a forward bias voltage to the electroluminescent element to emit light by the stimulated emission, said first A forward bias voltage smaller than the first drive circuit is connected to a second drive circuit that can be turned on and off, and forward bias voltage application by the first drive circuit and the second drive circuit is turned on, In response to the voltage drop, the electroluminescent element emits light by increasing the current flowing with respect to the voltage increase, and then the forward bias voltage application by the first drive circuit is turned off after reaching the breakover voltage. increasing the current through Te, to turn OFF the forward bias voltage is applied more by the second driving circuit It allows, characterized in that extinguishing the electroluminescent device.

  According to the present invention having the above-described configuration, it is possible to provide an electroluminescence element capable of improving light emission efficiency in the near infrared in an EL element using silicon as a light emitting material.

It is a block diagram of the light emission controller of the EL element to which the present invention is applied. It is a figure which shows the example which mounts an EL element in a light emission controller. It is an energy band figure of the junction part of the semiconductor layer which consists of n layer and p layer. (A) is a figure which shows the example of the microscopic shape of the junction part of n layer and p layer before Joule heat generation, (b) is the n layer and p layer after generating Joule heat It is a figure which shows the example of the microscopic shape of this junction part. It is a figure which shows the model which replaced the coupling | bonding of atoms with the spring for demonstrating a non-adiabatic process. It is a figure for demonstrating the inversion distribution formed in the junction part of the semiconductor layer which consists of n layer and p layer. It is a figure for demonstrating the multistep stimulated emission based on a non-adiabatic process. It is a figure for demonstrating the mechanism in the case of producing a non-adiabatic process continuously. It is a figure which shows the density | concentration distribution with respect to the depth direction of the boron as a p layer with respect to the silicon substrate as an n layer. It is a figure which shows the voltage-current characteristic in the EL element to which this invention is applied.

  Hereinafter, a light emission controller of an electroluminescence element (hereinafter referred to as an EL element) to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram of a light emission controller 10 of an EL element 1 to which the present invention is applied. The light emission controller 10 is configured to turn on / off a larger forward bias voltage for the EL element 1 and turn on / off a smaller forward bias voltage for the EL element 1. And a second drive circuit 5 which can be turned off.

  The first drive circuit 4 includes a power supply 41 for applying a positive voltage to the p layer 14 of the EL element 1 and a negative voltage to the n layer 13 in order to load a forward voltage to the EL element 1. A switch 42 is provided for performing ON / OFF control of the circuit. The first drive circuit 4 may be further provided with a control means (not shown) for controlling the size of the power supply 41.

  The second drive circuit 5 includes a power supply 51 for applying a positive voltage to the p layer 14 of the EL element 1 and a negative voltage to the n layer 13 in order to load a forward voltage to the EL element 1. A switch 52 for performing ON / OFF control of the circuit is provided. The second drive circuit 5 may be further provided with a control means (not shown) for controlling the size of the power supply 51. Incidentally, the value of the load voltage by the power supply 51 is set to be lower than that of the power supply 41.

  FIG. 2 shows an example in which the EL element 1 is actually mounted on the light emission controller 10. The EL element 1 is bonded on the mount 60. At this time, the EL element 1 is bonded so that the p layer 14 is on top and the n layer 13 is in contact with the mount 60.

Then, the minus side of the second drive circuit 5 is connected to the mount 60. The plus side of the second drive circuit 5 is connected to the submount 40. The submount 40 and the upper surface of the EL element 1 are connected by a gold wire 49. Incidentally, in the state where there is no gold wire 49, the submount 40 and the mount 60 are configured to be electrically disconnected from each other.

The first drive circuit 4 has a positive side connected to the submount 50a and a negative side connected to the submount 50b. The submount 50a and the upper surface of the EL element 1 are connected by a gold wire 59a. Further, the submount 50b and the mount 60 are connected by a gold wire 59b. Incidentally, the submounts 50a and 50b and the mount 60 are configured to be electrically disconnected from each other in the absence of the gold wire 49.

  Such a connection shown in FIG. 2 makes it possible to realize a block configuration as shown in FIG.

  Next, the configuration of the EL element 1 will be described in detail with reference to the drawings.

  The EL element 1 is formed between an N-type semiconductor layer (n layer) 13 and a P-type semiconductor layer (p layer) 14 constituting a pn junction with the n layer 13, and between the n layer 13 and the p layer 14. The bonding layer 35 is provided. The layers from n layer 13 to p layer 14 are referred to as semiconductor layer 30. A power supply 2 is connected to the p layer 14, and in use, a bias voltage is loaded in the forward direction so that the p layer 14 side is a positive voltage and the n layer 13 side is a negative voltage.

The n layer 13 is composed of a so-called silicon substrate or the like, but is not limited to this, and may be another indirect semiconductor. Here in addition to Si Representative indirect inorganic compounds, GaP, AlGaAs (depending on alloy composition), AlP, AlAs, Ge, SiC, PbS, PbTe, TIO 2, GaS, AlSb ,, C ( diamond) , BN, etc., and this method can be applied to all of them.

The p layer 14 is configured by implanting, for example, boron or the like as a p-type dopant with high density and high energy. The p layer 14 may have a doping density of 10 ^{19 at} , for example, 700 KeV and around 500 nm from the surface.

  When manufacturing such an EL element 1, a forward bias voltage is applied to the p layer and the n layer. As a result, the EL element 1 according to the present invention can be manufactured based on the following mechanism.

  FIG. 3 shows an energy band diagram of the semiconductor layer 30 including the n layer 13 to the p layer 14. When a forward bias voltage is applied, holes in the p layer 14 move to the n layer 13 side, and electrons in the n layer 13 move to the p layer 14 side. As a result, the junction layer 35 is not depleted and a diffusion current flows by mutual cancellation of electrons and holes. As a result, when the forward bias voltage is high, Joule heat is generated due to the movement of the electrons. The particularly large generation site of the Joule heat is the surface of the bonding layer 35, the n layer 13 or the p layer 14 that generates a large potential difference. Further, by increasing the forward bias voltage, an avalanche breakdown occurs in the junction layer 35, and current flows at a stroke. As a result, heat generation due to Joule heat is promoted by such avalanche breakdown.

  As a result of the generation of the Joule heat, the fluidity in the bonding layer 35, the n layer 13 and the p layer 14 is increased, and the surface shape and / or the distribution of the dopant is changed. By continuing to apply the forward bias voltage described above, such surface shape and / or dopant distribution changes will continue to occur.

  FIG. 4A is an example of a microscopic shape of the bonding layer 35 of the n layer 13 and the p layer 14 before the generation of Joule heat. At the junction interface between the n layer 13 and the p layer 14, nano-order fine irregularities are formed.

  FIG. 4B is an example of a microscopic shape of the bonding layer 35 of the n layer 13 and the p layer 14 after Joule heat is generated. By generating Joule heat, the fluidity of the bonding layer 35 of the n layer 13 and the p layer 14 is increased. As a result, the surface shape of the n layer 13, the p layer 14, etc., and the dopant distribution change randomly. Become. As a result of repeated changes in the surface shape and dopant distribution, for example, a specific fine shape A is formed at the interface between the n layer 13 and the p layer 14. This fine shape A is a shape more suitable for generating near-field light based on incident light. The conditions for forming the fine shape A are not fixed, and as a result of random changes in the surface shape and dopants of the n layer 13 and the p layer 14 and the like accompanying the generation of Joule heat, it happens by chance with a certain probability. Is formed. The near-field light is not limited to the case where the near-field light is generated at the interface between the n layer 13 and the p layer 14, and the surface shape and / or dopant distribution of any one or more layers constituting the EL element 1. As long as it changes the value.

  When such a fine shape A is formed, if the forward bias voltage described above is further applied, near-field light is generated mainly at the corners of the fine shape A. Since the near-field light here includes the meaning of a virtual electromagnetic field, the formation of a virtual electromagnetic field is understood as meaning the generation of near-field light. The generation of the near-field light is generated by spontaneous emission of the injected charge and stimulated emission based on it when the forward current is injected, even in the absence of the induced light. Generation of this near-field light causes a non-adiabatic process described below. Incidentally, the generation position of the near-field light may naturally occur not only at the interface between the n layer 13 and the p layer 14 corresponding to the fine shape A but also at other locations.

  This non-adiabatic process can be considered by a model in which the bonds between atoms are replaced by springs as shown in FIG. In general, the wavelength of propagating light is much larger than the size of the molecule, so it can be regarded as a spatially uniform electric field at the molecular level. As a result, as shown in FIG. 5A, adjacent electrons are vibrated with the same amplitude and the same phase by the spring. Since the atomic nucleus of the photosensitive resin film 12 is heavy, it cannot follow the vibration of the electrons, and the molecular vibration is hardly caused in the propagating light. In this way, in propagation light, it can be ignored that molecular vibrations are involved in the excitation process of electrons, so this process is called an adiabatic process (see Non-Patent Document 1).

  On the other hand, the spatial electric field gradient of near-field light drops very steeply. For this reason, near-field light gives different vibrations to adjacent electrons, and as shown in FIG. 5B, heavy nuclei are also vibrated by the vibrations of the different electrons. The occurrence of molecular vibration in the near-field light corresponds to energy taking the form of molecular vibration. Therefore, in the near-field light, an excitation process (non-adiabatic process) via the vibration level is possible. Thus, the excitation process via the vibration level of the nucleus is called a non-adiabatic process because the nucleus moves in response to the adiabatic process that is a normal optical response (see Non-Patent Document 1).

Further, by continuing to apply the forward bias voltage described above, the electron density n ₁ in the conduction band is overwhelmingly higher than the hole density n ₂ in the lower level. As a result, an inversion distribution based on the difference in electron density is formed in the bonding layer 35 between the conduction band and the lower level as shown in FIG. Next, as shown in FIG. 7 (a), the inversion distribution thus formed causes the electrons in the conduction band to be positioned in the middle of the band gap based on the non-adiabatic process by near-field light. It is possible to make a virtual transition to the vibration level. The fact that the electrons were able to transit to the vibration level based on the non-adiabatic process was realized because near-field light was generated at that location. This near-field light is generated by the fine shape A (or a change in its dopant) generated under a certain probability due to the flow due to Joule heat. The electrons that have transitioned to the vibration level travel around the virtual field that is virtually generated by the near-field light, and then return from the vibration level to the conduction band. The electrons returning to the conduction band contribute to Joule heat due to the diffusion current.

  Thus, at the stage where the near-field light is simply generated, the electrons in the conduction band are virtually transitioned to the vibration level and returned to the conduction band again. The electrons returning to the conduction band contribute to Joule heat, and the Joule heat does not decrease, and the surface shape and / or dopant distribution change continues.

  As a result of changes in the surface shape and / or dopant distribution due to Joule heat, if the generation mode of near-field light further changes, as shown in FIG. Based on a non-adiabatic process of near-field light, the electrons in the conduction band are caused to emit light by virtually transitioning to an oscillation level located in the middle of the band gap and emitting the electrons therefrom. Further, light is emitted by stimulated emission of electrons in the conduction band in a plurality of steps based on such near-field light.

  As a result, light emission by emission of electrons from the EL element 1 can be realized. In the fine shape A, near-field light continues to be generated, so that a non-adiabatic process can be generated. In stimulated emission by this non-adiabatic process, electrons are emitted through vibration levels. At this time, even in the light having a wavelength longer than the absorption edge wavelength corresponding to the band gap width, electrons in the conduction band can be emitted in a multi-stage transition, thereby reducing the electrons in the conductor. It becomes possible.

The multistage stimulated emission caused by such a non-adiabatic process causes the electron density n ₁ in the conduction band to decrease. As a result, for the fine shape A in which such near-field light is generated, the amount of electrons moving to the n layer 13 is reduced, the diffusion current is reduced, and the Joule heat is reduced for the fine shape A. It will be. That is, stimulated emission takes away energy of electrons and holes, and the fluidity of the bonding layer 35, the n layer 13, and the p layer 14 decreases. As a result, for the fine shape A, changes in the surface shape and / or dopant distribution are suppressed. The fine shape A is fixed without change.

  Further, when light emission occurs as shown in FIG. 7B, near-field light based on the surface shape and / or dopant distribution is likely to be generated based on the light emission. Due to the generated near-field light, a non-adiabatic process is more likely to occur in each part, and the fine structure A is fixed and light emission is promoted.

  Moreover, the mechanism described above is continuously generated by continuing to apply the forward bias voltage as described above. As shown in FIG. 8A, in the fine shape A, the near-field light continues to be generated as it is, and the stimulated emission by the non-adiabatic process described above is continuously generated. It remains fixed as it is. Further, since the near-field light is not generated in the portions other than the fine shape A, the fluidity of the bonding layer 35 between the n layer 13 and the p layer 14 is increased by generating Joule heat as it is without being cooled. As a result, the surface shape of the n layer 13 and the p layer 14 and the distribution of the dopant change randomly. As a result of this random change, as shown in FIG. 8A, a fine shape B having a shape substantially the same as the fine shape A may be formed. When light is incident in such a case, near-field light is generated in the fine shape B. And also about this fine shape B, as a result of the stimulated emission by the non-adiabatic process, the temperature is lowered and the shape B continues to be fixed as it is. That is, the area where the near-field light is suitably generated in the EL element 1 is increased not only in the fine shape A but also in the fine shape B.

  When this process is repeatedly performed, ideally, many shapes identical to the fine shape A are formed at the interface between the n layer 13 and the p layer 14 as shown in FIG. 8B. This makes it possible to configure the EL element 1 in which a number of the same shapes as the fine shape A in which near-field light is suitably generated when a forward bias voltage is applied. As a result, the luminous efficiency can be dramatically improved.

  The fine shape A depends only on the surface shape, but is not limited to this, and as a result of changes in dopants such as the n-layer 13 and the p-layer 14 caused by the generation of Joule heat, Even if the shape does not change, there may be a condition that the near-field light is suitably generated. Even when the dopants such as the n layer 13 and the p layer 14 are changed so that near-field light can be suitably generated, the same effect as the formation of the fine shape A described above can be obtained. That is, the dopant distribution is fixed repeatedly by decreasing the diffusion current and decreasing the Joule heat.

  FIG. 9 shows the concentration distribution in the depth direction of boron as the p layer 14 with respect to the silicon substrate as the n layer 13 in the method for manufacturing an EL element to which the present invention is applied. FIG. 9A shows the concentration distribution in the depth direction of boron immediately after implanting boron as the p layer 14 with respect to the silicon substrate as the n layer 13, and FIG. The figure shows the boron concentration distribution after a directional bias voltage is applied and boron as a dopant is flowed and further fixed. From FIG. 9, it is shown that the dopant distribution is changed to a suitable one for generating near-field light as a result of flow caused by Joule heat caused by the diffusion current. 11Boron and 12Boron in this figure mean the isotopes of B, respectively.

  Next, the operation of the EL element 1 manufactured based on the manufacturing method of the light receiving element to which the present invention is applied will be described.

  As described above, the EL element 1 is formed with a wide area such as the fine structures A and B in which near-field light is suitably generated when a forward bias voltage is applied in the production stage. ing. A forward bias voltage may be applied to such an EL element 1. As a result, since a shape capable of generating near-field light has already been created, near-field light is generated in many regions as shown in FIG. 8B. Then, as shown in FIG. 7 (b), electrons in the conduction band are stimulated and emitted in multiple stages to emit light by the non-adiabatic process by the generated near-field light. At this time, when the intensity of the forward bias voltage is further increased, avalanche breakdown occurs and the amount of light emission is further increased.

  FIG. 10 shows voltage-current characteristics in the EL element 1 to which the present invention is applied. In this current characteristic, almost no current flows until the bias voltage is gradually increased to reach over 100V, but when it exceeds 100V, it is shown that a very good differential negative resistance characteristic appears. Also, Joule heat generation due to the forward bias voltage occurs also in the PN junction that shows normal resistance characteristics, so the appearance of negative resistance is not essential for this method, but in this example, dopant nonuniformity is an electrical element. Since the distribution also functions, the possibility of functioning as an excellent rectifying element is suggested, and FIG. 10 shows the tendency of the electrical characteristics.

  As described above, in the present invention, a diffusion current is generated at the junction between the p layer 14 and the n layer 13 by applying a forward bias voltage, and the EL element 1 is based on the Joule heat generated by the generated diffusion current. To repeatedly change the surface shape and / or dopant distribution of any one or more of the layers.

  And in the place where near-field light is generated based on the surface shape after the change and / or the dopant distribution, the diffusion current is decreased by causing the electrons in the conduction band to be induced and emitted in multiple steps based on the non-adiabatic process. The Joule heat is lowered to fix the surface shape and / or dopant distribution.

  In addition, conditions that are suitable for emitting light in a place where near-field light is not generated based on the surface shape and / or dopant distribution after the change, or even if near-field light is generated simply because a virtual field is formed are satisfied. In a place where there is not, the generation of the diffusion current and the change of the surface shape and / or the dopant distribution are repeated until light is emitted in the non-adiabatic process by the near-field light.

  Accordingly, in the present invention, light having a wavelength longer than the absorption edge wavelength corresponding to the band gap width of the bonding layer 35 can be emitted. If the n layer 13 is silicon, it is possible to emit light in the near infrared region as the emission wavelength of the silicon.

  In addition, in the method for manufacturing the EL element 1 to which the present invention is applied, a light receiving element having excellent sensitivity to a desired wavelength can be manufactured at a low cost without requiring a particularly large apparatus.

The wavelength band above Si, GaP, (depending on alloy composition) AlGaAs, AlP, AlAs, Ge , SiC, PbS, PbTe, TIO 2, GaS, AlSb, C ( diamond), an indirect transition type inorganic employed such as BN By changing the type of material, a wide range from ultraviolet to infrared light can be dealt with.

  Further, according to the present invention, as shown in FIG. 10, after exceeding 100 V, it is possible to obtain an EL element 1 in which the current has a negative dependency on the forward bias voltage. For this reason, in this invention, it can apply to various circuits as a rectifier circuit which can express the function as this negative resistance.

  An example in which the light emission control of the EL element 1 is controlled by using the negative resistance characteristic of the EL element 1 will be described below.

  Table 1 shows the order of ON / OFF control of the light emission controller 10 to which the present invention is applied. First, the first drive circuit 4 and the second drive circuit 5 are turned on. Either the first drive circuit 4 and the second drive circuit 5 may be turned on first or may be turned on simultaneously.

  When both the first drive circuit 4 and the second drive circuit 5 are turned on, the load voltage exceeds 100 V and exceeds the point P shown in FIG. This point P is called BOV (breakover voltage), and beyond this, the above-described element exhibits negative resistance characteristics. When this BOV is exceeded, a large amount of current flows even if the voltage drops.

  Therefore, even if the first drive circuit 4 is turned OFF at this stage and the power supply to the EL element 1 is only supplied to the second drive circuit 5, the second drive circuit 5 has a low voltage but a current. Therefore, the current-voltage characteristic changes along the arrow Q direction shown in FIG. Finally, it reaches the R point. Meanwhile, light emission from the EL element 1 is continued. In addition, when the current-voltage characteristics change along the Q, it is possible to increase the flowing current and improve the emission intensity. Of course, the second drive circuit 5 does not require a high voltage. Similarly, the first drive circuit 4 only needs to have a high voltage, and does not need the performance of flowing a large amount of current. That is, the present invention can be realized by using the low voltage / high current second drive circuit 5 and the high voltage / low current first drive circuit 4. It is also an advantage of the present invention that a large drive circuit is not required for simultaneous generation.

  Next, the first drive circuit 4 is turned off. By turning off the first drive circuit 4, the voltage applied to the EL element 1 is reduced, and the state of the R point is maintained in the current-voltage characteristics. In the meantime, the light emission from the EL element 1 is continued.

  Next, the second drive circuit 5 is turned off. As a result, the current decreases along the path indicated by the dotted line in the figure, and the light from the EL element 1 is quenched.

DESCRIPTION OF SYMBOLS 1 EL element 2 Power supply 4 1st drive circuit 5 2nd drive circuit 10 Light emission controller 13 n layer 14 p layer 30 Semiconductor layer 35 Junction 40, 50 Submount 41, 51 Power supply 42, 52 Switch 49, 59 Gold Wire 60 mount

Claims (2)

In a light emission controller of an electroluminescence device comprising a semiconductor layer including a p layer and an n layer,
By applying a forward bias voltage, a diffusion current is generated at the junction between the p layer and the n layer, and the surface shape of any one or more of the layers based on the Joule heat generated by the generated diffusion current, and Repeated change of dopant distribution and / or inversion distribution in conduction band and valence band by forward bias voltage, and near-field light is generated based on surface shape and / or dopant distribution after change. In this place, electrons in the conduction band forming the inversion distribution are induced and emitted in multiple stages based on a non-adiabatic process, thereby reducing the diffusion current and reducing the Joule heat, An electroluminescence device that fixes the surface shape and / or dopant distribution and emits light by the stimulated emission;
A first driving circuit capable of freely turning on / off a forward bias voltage with respect to the electroluminescence element;
A second driving circuit capable of turning ON / OFF a forward bias voltage smaller than that of the first driving circuit with respect to the electroluminescence element;
By turning on forward bias voltage application by the first drive circuit and the second drive circuit , the current flowing with respect to the increase in voltage is increased to cause the electroluminescence element to emit light,
Next, after reaching the breakover voltage, by turning off the forward bias voltage application by the first drive circuit , the current flowing according to the voltage drop is increased,
Further, the electroluminescence element is extinguished by turning off forward bias voltage application by the second drive circuit, and the electroluminescence element emission controller. In a method for controlling light emission of an electroluminescence element comprising a semiconductor layer including a p layer and an n layer,
By applying a forward bias voltage, a diffusion current is generated at the junction between the p layer and the n layer, and the surface shape of any one or more of the layers based on the Joule heat generated by the generated diffusion current, and Repeated change of dopant distribution and / or inversion distribution in conduction band and valence band by forward bias voltage, and near-field light is generated based on surface shape and / or dopant distribution after change. In this place, electrons in the conduction band forming the inversion distribution are induced and emitted in multiple stages based on a non-adiabatic process, thereby reducing the diffusion current and reducing the Joule heat, together to fix the surface shape and / or dopant profile, the forward direction to the electroluminescent element to emit light by the stimulated emission And ON / OFF freely first driving circuit bias voltage, and connect the first driving circuit smaller forward bias voltage to the ON / OFF freely second driving circuit,
By turning on forward bias voltage application by the first drive circuit and the second drive circuit , the current flowing with respect to the increase in voltage is increased to cause the electroluminescence element to emit light,
Next, after reaching the breakover voltage, by turning off the forward bias voltage application by the first drive circuit , the current flowing according to the voltage drop is increased,
Furthermore, the electroluminescence element is extinguished by turning off forward bias voltage application by the second drive circuit, and the light emission control method for the electroluminescence element.

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