JP7369538B2 - dye-sensitized solar cells - Google Patents

Description

The present invention relates to dye-sensitized solar cells.

Dye-sensitized solar cells are attracting attention as a new solar cell to replace silicon-based solar cells. Dye-sensitized solar cells can efficiently generate electricity even in low-light environments such as indoors or at dusk, so they are expected to be applied to power-saving applications such as IoT (Internet of Things) devices. In that case, by mounting a dye-sensitized solar cell on the wiring board built into the IoT device, electronic devices such as sensors within the IoT device can be driven by the power of the dye-sensitized solar cell.

Various solar cells have been proposed so far that are designed to be mounted on wiring boards, but all of them have room for improvement.

For example, a dye-sensitized solar cell has been disclosed in which the power generation part that generates power on the surface of the package substrate is surrounded with a sealing material to prevent electrolyte solution from leaking from the power generation part (Patent Document 1). However, in this dye-sensitized solar cell, it is necessary to secure a space on the package substrate for providing a sealing material, so the area of the power generation section must be made small, and a sufficient amount of power generation cannot be obtained.

Furthermore, a technique has been disclosed in which an electrode pad is provided on a transparent base material included in a dye-sensitized solar cell, and the electrode pad and a wiring board are connected by solder (Patent Document 2). With this technology, heat is easily transferred to the dye-sensitized solar cell, so there was a risk that its characteristics would deteriorate.

Japanese Patent Application Publication No. 2010-80122 JP2011-243298A

The present invention has been made in view of the above problems, and an object of the present invention is to provide a dye-sensitized solar cell capable of increasing the amount of power generation.

The dye-sensitized solar cell according to the present invention includes a transparent base material, a transparent electrode layer provided on the transparent base material, a power generation layer containing a dye provided on the transparent electrode layer, and a power generation layer provided on the transparent base material. It is characterized by having a solid electrolyte layer provided on the solid electrolyte layer, a counter electrode layer provided on the solid electrolyte layer, and a resin base material fixed to the upper surface of the counter electrode layer.

In the dye-sensitized solar cell, the resin base material has a first main surface fixed to the upper surface of the counter electrode layer, and a second main surface that is opposite to the first main surface. , a first via hole and a second via hole are formed in the resin base material, a first via conductor formed in the first via hole and electrically connected to the transparent electrode layer, and a first via conductor formed in the first via hole and electrically connected to the transparent electrode layer; a second via conductor formed in the via hole and electrically connected to the counter electrode layer; a first electrode pad provided on the second main surface and connected to the first via conductor; The device may further include a second electrode pad provided on the second main surface and connected to the second via conductor.

In the dye-sensitized solar cell, the first via conductor and the second via conductor may be provided at an edge of the resin base material.

In the dye-sensitized solar cell, the resin base material is polygonal in plan view, and the first via conductor is provided at one of the two corners of the polygon, and the second via conductor is provided at the other corner. Via conductors may also be provided.

In the dye-sensitized solar cell, the first via hole and the second via hole are provided outside a cell region where each of the transparent electrode layer, the solid electrolyte layer, and the counter electrode layer overlap in plan view. It's okay.

In the dye-sensitized solar cell, the first via conductor is connected to the counter electrode layer in the first contact region outside the cell region, and the second via conductor is connected to the counter electrode layer in the first contact region outside the cell region. The transparent electrode layer may be connected to the outer second contact region.

In the dye-sensitized solar cell, the solid electrolyte layer is provided in a size that fits within the cell region in plan view, and includes an insulating layer provided on the transparent electrode layer in the first contact region, and a conductive layer provided on the transparent electrode layer in the second contact region, the counter electrode layer provided on the insulating layer in the first contact region, and a conductive layer provided on the transparent electrode layer in the first contact region; In the contact region, the transparent electrode layer and the second via conductor may be connected via the conductive layer.

In the dye-sensitized solar cell, the conductive layer may be provided at a distance from the solid electrolyte layer in plan view, and the insulating layer may also be provided between the solid electrolyte layer and the conductive layer. good.

In the above dye-sensitized solar cell, the transparent electrode layer in the first contact region may be separated from the transparent electrode layer in the cell region.

In the dye-sensitized solar cell, a side surface of the power generation layer and a side surface of the transparent base material may be in the same plane.

According to the present invention, it is possible to provide a dye-sensitized solar cell that can increase the amount of power generated.

(a) and (b) are perspective views (part 1) of the dye-sensitized solar cell according to the first example during manufacture. (a) and (b) are perspective views (part 2) of the dye-sensitized solar cell according to the first example during manufacture. (a) to (c) are cross-sectional views (part 1) of the wiring board in the middle of manufacturing according to the first embodiment. (a) to (c) are cross-sectional views (part 2) of the wiring board according to the first embodiment during manufacture. (a) is a perspective view of the wiring board according to the first embodiment when the second main surface of the resin base material is facing up, and (b) is a cross section taken along line BB in (a). It is a diagram. FIG. 2 is a perspective view of the wiring board according to the first example when the first main surface of the resin base material is facing upward. FIG. 3 is a perspective view (part 3) of the dye-sensitized solar cell according to the first example during manufacture. FIG. 4 is a perspective view (No. 4) of the dye-sensitized solar cell according to the first example during manufacture. FIG. 5 is a perspective view (No. 5) of the dye-sensitized solar cell according to the first example during manufacture. (a) is a sectional view taken along line CC in FIG. 8, and (b) is a sectional view taken along line DD in FIG. 8. FIG. 2 is a cross-sectional view for explaining an example of how to use the dye-sensitized solar cell according to the first example. (a) and (b) are perspective views (part 1) of a dye-sensitized solar cell according to a second example during manufacture. (a) and (b) are perspective views (part 2) of the dye-sensitized solar cell according to the first example during manufacture. (a) and (b) are perspective views of a wiring board used in this example. (a) is a sectional view taken along line EE in FIG. 14(a), (b) is a sectional view taken along line FF in FIG. 14(a), and (c) is a sectional view taken along line FF in FIG. 14(a). ) is a sectional view taken along line GG. FIG. 3 is a perspective view (part 3) of the dye-sensitized solar cell according to the second example during manufacture. FIG. 4 is a perspective view (No. 4) of a dye-sensitized solar cell according to a second example during manufacture. FIG. 5 is a perspective view (No. 5) of the dye-sensitized solar cell according to the second example during manufacture. (a) is a cross-sectional view taken along line HH in FIG. 17, and (b) is a cross-sectional view taken along line JJ in FIG. 17.

(First example)
The dye-sensitized solar cell according to this example will be explained while following its manufacturing method. FIGS. 1(a) to 2(b) are perspective views of the dye-sensitized solar cell according to the first example during manufacture.

First, as shown in FIG. 1(a), a transparent base material 20 having a first main surface 20a and a second main surface 20b facing each other is prepared. Among these main surfaces, the first main surface 20a becomes an entrance surface through which light enters during actual use. On the other hand, on the second main surface 20b, an ITO (Indium Tin Oxide) layer is formed in advance as a transparent electrode layer 21 to a thickness of about 0.1 μm to 0.5 μm. Note that instead of the ITO layer, any of the FTO (Fluorine doped Tin Oxide) layer, the zinc oxide layer, the laminated film of the indium-tin composite oxide layer and the silver layer, and the antimony-doped tin oxide layer is used as a transparent layer. It may also be formed as the electrode layer 21.

Further, the transparent base material 20 is a glass substrate, and the length Ax of the long side is 5 mm to 40 mm, for example, 20 mm, and the length Ay of the short side is 5 mm to 20 mm, for example 15 mm. Further, the thickness Az of the transparent base material 20 is 0.1 mm to 3.0 mm, for example, 1.1 mm. Note that a transparent plastic plate may be used as the transparent base material 20 instead of the glass substrate.

Next, as shown in FIG. 1(b), an alcohol solution prepared from titanium alkoxide is applied onto the transparent electrode layer 21 in the cell region I, and then the alcohol solution is heated and dried to generate reverse electrons. The movement prevention layer 22 is formed to have a thickness of about 5 nm to 0.1 μm. The drying temperature in this step is not particularly limited, and may be carried out at a temperature of 450°C to 650°C, for example, about 550°C.

Note that the cell region I is a region in the transparent base material 20 where solar cells are formed. Further, the area next to the cell area I becomes a peripheral area II in which a via conductor for extracting power from the solar battery cell will be formed later.

The shape and size of each region I, II are not particularly limited. The cell region I is a square region with a side length L of 1 mm to 20 mm, for example 15 mm, in plan view. Further, the peripheral region II has a rectangular shape in a plan view, the length By of the long side is 1 mm to 20 mm, for example 15 mm, and the length Bx of the short side is 1 mm to 10 mm, for example 5 mm.

Next, as shown in FIG. 2(a), a slurry in which titanium oxide particles with a particle size of 5 nm to 50 nm are dispersed is screen printed onto the reverse electron transfer prevention layer 22 to a thickness of about 1 μm to 10 μm. The power generation layer 25 is formed by coating and heating it to remove organic components. As the slurry, for example, PST-30NRD, which is a titanium oxide paste manufactured by JGC Catalysts and Chemicals, is used. The heating temperature of the slurry is 450° C. to 650° C., for example 550° C., and the drying time is 10 minutes to 120 minutes, for example about 30 minutes.

Note that the semiconductor particles constituting the power generation layer 25 are not limited to titanium oxide particles, but include Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, and Sn. , Zr, Sr, Ga, Si, Cr, and Nb. Furthermore, the power generation layer 25 may be formed of particles of perovskite oxide such as SrTiO ₃ and CaTiO ₃ .
Further, the region where the power generation layer 25 is formed is the same square region as the cell region I (see FIG. 1(b)).

Thereafter, the transparent base material 20 is immersed in an organic solution containing a dye, and the dye is adsorbed onto the surface of the semiconductor particles constituting the power generation layer 25. The organic solution and dipping conditions are also not particularly limited. For example, prepare an organic solvent in which acetonitrile and t-butanol are mixed at a volume ratio of 1:1, and add CYC-B11 (K) as a dye to the organic solvent at a concentration of 0.1 to 1 mM, for example, 0.2 mM. An added organic solution can be used in this step. Then, the transparent base material 20 is immersed in the organic solution for 1 hour to 12 hours, for example 4 hours, while keeping the organic solution at a temperature of 0° C. to 80° C., for example, 50° C., so that the dye is adsorbed to the power generation layer 25. That's fine.

Further, the dye is not limited to the above, and a metal complex dye or an organic dye may be adsorbed onto the power generation layer 25. Among these, examples of metal complex dyes include transition metal complexes such as ruthenium-cis-diaqua-bipyridyl complex, ruthenium-tris complex, ruthenium-bis complex, osmium-tris complex, and osmium-bis complex. Furthermore, zinc-tetra(4-carboxyphenyl)porphyrin and iron-hexacyanide complexes are also examples of metal complex dyes.

Examples of organic dyes include 9-phenylxanthene dyes, coumarin dyes, acridine dyes, triphenylmethane dyes, tetraphenylmethane dyes, quinone dyes, azo dyes, indigo dyes, and cyanine dyes. There are pigments such as merocyanine pigments, xanthene pigments, and carbazole compound pigments.

Next, the process shown in FIG. 2(b) will be explained. First, as the solid electrolyte precursor 26, iodine, 1,3-dimethylimidazolium iodide (DMII), acetonitrile, and polyethylene oxide having a molecular weight of 1 million are mixed uniformly. Next, 0.1 μL to 50 μL, for example 20 μL, of this solid electrolyte precursor 26 is dropped onto the power generation layer 25 to impregnate the power generation layer 25 with the solid electrolyte precursor 26 . Then, by heating the power generation layer 25 to 50° C. to 150° C., for example 100° C., and maintaining this state for 1 minute to 60 minutes, for example 30 minutes, excess acetonitrile contained in the solid electrolyte precursor 26 is volatilized. , the solid electrolyte precursor 26 on the power generation layer 25 is used as a solid electrolyte layer 27. After that, the power generation layer 25 is returned to room temperature.

Note that the electrolyte contained in the solid electrolyte precursor 26 is not limited to DMII. For example, iodine salts such as pyridinium salts, imidazolium salts, triazolium salts, etc., which are solid at around room temperature or room temperature molten salts which are molten can be used as the ionic liquid. Examples of such room temperature molten salts include 4-iodide salts such as 1-methyl-3-propylimidazolium iodide, 1-butyl-3-methylimidazolium iodide (BMII), and 1-ethyl-pyridinium iodide. There are ammonium salt compounds, etc.

Furthermore, the material of the solid electrolyte layer 27 is not limited to the above, and organic semiconductor materials such as molten salts containing redox couples, oxadiazole compounds, and pyrazoline compounds may be used as the material of the solid electrolyte layer 27. . Further, the solid electrolyte layer 27 may be formed of a metal halide material such as copper iodide or copper bromide.
With the above steps, the processing for the transparent base material 20 is completed.

In this example, a dye-sensitized solar cell is manufactured by bonding a wiring board to this transparent base material 20. Next, a method for manufacturing the wiring board will be explained.

FIGS. 3(a) to 4(c) are cross-sectional views of the wiring board according to the present example during manufacture.

First, a double-sided copper-clad base material 30 shown in FIG. 3(a) is prepared. The double-sided copper-clad base material 30 is obtained by bonding a first copper foil 32 to a first main surface 31a of a resin base material 31 by heat pressing, and a second main surface 31b opposite to the first main surface 31a. It can be produced by bonding the copper foil 33 of No. 2 using hot press.

Although the resin base material 31 is not particularly limited, in this example, a glass epoxy substrate in which a glass woven cloth is impregnated with a heat-resistant epoxy resin is used as the resin base material 31. Note that a polyimide film may be used as the resin base material 31. Further, the thickness of the resin base material 31 is 0.1 mm to 3.2 mm, for example, 1 μm. Furthermore, the thickness of each copper foil 32, 33 is not particularly limited either. As an example, the thickness of each copper foil 32, 33 is 18 μm to 200 μm, for example 35 μm.

Subsequently, as shown in FIG. 3(b), a first via hole 31x is formed in the resin base material 31 by drilling the double-sided copper-clad base material 30. The diameter of the first via hole 31x is 0.1 mm to 2 mm, for example 0.25 mm.

Next, as shown in FIG. 3(c), an electroless copper plating layer is formed on the inner surface of the first via hole 31x and the surface of each copper foil 32, 33, and an electrolytic copper plating layer is further formed thereon. do. Note that the combined thickness of the electroless copper plating layer and the electrolytic copper plating layer is 10 μm to 30 μm, for example, about 20 μm. Then, each copper plating layer formed in the first via hole 31x is used as a first via conductor 36a, and each copper foil 32, 33 and these copper plating layers are used as a copper layer 37.

Next, as shown in FIG. 4A, the copper layer 37 is patterned by photolithography and wet etching to form a first electrode pad 37a and a first wiring 37b on the second main surface 31b. .

Subsequently, as shown in FIG. 4B, a gold layer 38 of 0.01 μm to 0.05 μm is deposited on each of the copper layer 37, the first electrode pad 37a, and the first wiring 37b by electroless plating. , for example, to have a thickness of about 0.03 μm. The plating method for forming the gold layer 38 with such a small thickness is also called flash plating.

Subsequently, as shown in FIG. 4C, a titanium layer and a platinum layer are formed in this order as a catalyst layer 39 on the copper layer 37 on the first main surface 31a side of the resin base material 31 by sputtering. , the copper layer 37, the gold layer 38, and the catalyst layer 39 are each used as a counter electrode layer 40.

Note that the titanium layer in the catalyst layer 39 functions as an adhesive layer, and its thickness is 0.05 μm to 0.5 μm, for example, about 0.1 μm. Further, the thickness of the platinum layer in the catalyst layer 39 is not particularly limited, and the catalyst layer 39 can be formed to have a thickness of about 0.01 μm to 0.3 μm, for example, about 0.05 μm.

Through the above steps, the basic structure of the wiring board 45 used in this embodiment is completed.

FIG. 5A is a perspective view of the wiring board 45 with the second main surface 31b of the resin base material 31 facing upward. Note that FIG. 4(c) described above corresponds to a cross-sectional view taken along line AA in FIG. 5(a).

As shown in FIG. 5A, a second electrode pad 37c is formed on the second main surface 31b of the resin base material 31 in the same process as the first electrode pad 37a described above. A second wiring 37d formed in the same process as the first wiring 37b is connected to the second electrode pad 37c.

The shape of the first electrode pad 37a is a square with a side length of 1 mm to 6 mm, for example, 5 mm in plan view. The shape of the second electrode pad 37c is also similar to this.
FIG. 5(b) is a cross-sectional view taken along line BB in FIG. 5(a).

As shown in FIG. 5(b), a second via hole 31y is formed in the resin base material 31 in the same process as the first via hole 31x. A second via conductor 36b is formed on the inner surface of the second via hole 31y in the same process as the first via conductor 36a, and one end of the second wiring 37d is connected to the second via conductor 36b. is connected to the via conductor 36b.

FIG. 6 is a perspective view of the wiring board 45 with the first main surface 31a of the resin base material 31 facing up.

As shown in FIG. 6, the aforementioned first via conductor 36a and second via conductor 36b are provided in the first contact region CR ₁ and the second contact region CR ₂ at the edge of the resin base material 31, respectively. . These contact regions CR ₁ and CR ₂ correspond to the peripheral region II outside the cell region I (see FIG. 2(b)), and are connected to the cell region I through the via conductors 36a and 36b. This is the area to extract.

A counter electrode layer 40 is formed in the first contact region CR ₁ , whereas a counter electrode layer 40 is not formed in the second contact region CR ₂ . As a result, one end of the second via conductor 36b and the resin base material 31 are exposed in the second contact region _CR2 .

Further, in this example, the area of the counter electrode layer 40 occupies 85% to 95% of the area of the first main surface 31a, for example, 87.5% or more. Furthermore, the width Bw of each contact region CR ₁ and CR ₂ is not particularly limited either, and is set to 5 mm to 10 mm, for example, about 7.5 mm.

The subsequent steps will be explained with reference to FIGS. 7 to 9. 7 to 9 are perspective views of the dye-sensitized solar cell according to this example during manufacture.

First, as shown in FIG. 7, the above-described transparent base material 20 is prepared again. Then, silver paste is applied as a conductive layer 43 on the transparent electrode layer 21 in the second contact region _CR2 . In order to prevent the conductive layer 43 and the solid electrolyte layer 27 from being electrically short-circuited, a space S is provided between the conductive layer 43 and the solid electrolyte layer 27, and the conductive layer 43 is formed at a distance from the solid electrolyte layer 27. preferable.

Next, an ultraviolet curable resin is applied onto the transparent electrode layer 21 in the first contact region CR ₁ , and then the ultraviolet curable resin is irradiated with ultraviolet rays and cured, thereby forming the insulating layer 44. In this example, by forming the insulating layer 44 also in the space S between the solid electrolyte layer 27 and the conductive layer 43, the solid electrolyte layer 27 and the conductive layer 43 are insulated by the insulating layer 44.

Then, the wiring board 45 is arranged above the transparent base material 20, and the solid electrolyte layer 27 of the transparent base material 20 and the first main surface 31a of the resin base material 31 are made to face each other.

Next, as shown in FIG. 8, the transparent base material 20 and the resin base material 31 are pasted together and heated to a temperature of about 50°C. As a result, the conductive layer 43 is solidified, and the second via conductor 36b and the transparent electrode layer 21 are connected via the conductive layer 43.

Note that in order to prevent air bubbles from entering between the transparent base material 20 and the wiring board 45, it is preferable to perform this step in a vacuum or a reduced pressure atmosphere.

Moreover, by pasting the transparent base material 20 and the resin base material 31 together in this way, each of the transparent electrode layer 21, the power generation layer 25, the solid electrolyte layer 27, and the counter electrode layer 40 can be seen in plan view in the cell region I. It will overlap.
FIG. 10(a) is a cross-sectional view taken along line CC in FIG.

As shown in FIG. 10(a), in the cell region I, a counter electrode layer 40 is fixed to the first main surface 31a of the resin base material 31, and a solid electrolyte layer 27 and a transparent electrode layer 21 are disposed under the counter electrode layer 40. is formed. When light enters the power generation layer 25 via the transparent base material 20 and the transparent electrode layer 21, an electromotive force is generated in the cell region I, and a potential difference caused by the electromotive force is caused between the transparent electrode layer 21 and the counter electrode layer. Occurs between 40 and 40. In addition, in this example, the transparent electrode layer 21 becomes a negative electrode, and the counter electrode layer 40 becomes a positive electrode.

Further, in the cell region I, the power generation layer 25 is formed over the entire width of the transparent base material 20, so that the side surface 20s of the transparent base material 20 and the side surface 25s of the power generation layer 25 are located on the same plane P. This increases the amount of light received by the power generation layer 25 compared to the case where the power generation layer 25 is formed on the transparent base material 20 so that the side surface 25s is set back from the side surface 20s, increasing the amount of power generation in the cell region I. becomes possible.
On the other hand, FIG. 10(b) is a cross-sectional view taken along line DD in FIG.

As shown in FIG. 10(b), in the first contact region _CR1 , the counter electrode layer 40 and the first via conductor 36a are connected, and the positive voltage of the counter electrode layer 40 is applied to the resin base material 31. is pulled out to the second main surface 31b side. Further, since the insulating layer 44 is interposed between the transparent electrode layer 21 and the counter electrode layer 40, the insulating layer 44 prevents an electrical short circuit between the first via conductor 36a and the transparent electrode layer 21. This can be prevented by

On the other hand, in the second contact region _CR2 , the second via conductor 36b and the transparent electrode layer 21 are connected via the conductive layer 43, and the negative voltage of the transparent electrode layer 21 is applied to the second via conductor 36b. It is pulled out to the second main surface 32b side of the resin base material 31 via.

After this, as shown in FIG. 9, after applying an ultraviolet curable resin as a sealing resin 47 to each side of the transparent base material 20 and the resin base material 31, the sealing resin 47 is cured by irradiation with ultraviolet rays. The sealing resin 47 prevents moisture from entering the solid electrolyte layer 27 and the like. Note that the sealing resin 47 may be formed by applying an ultraviolet curable resin so as to cover a portion of the second main surface 31b of the resin base material 31.

Through the above steps, the basic structure of the dye-sensitized solar cell 50 according to this example is completed.

The dye-sensitized solar cell 50 does not use a liquid electrolyte, but uses a solid electrolyte layer 27 with no possibility of liquid leakage. Therefore, there is no possibility that the electrolyte will leak from the via holes 31x, 31y (see FIG. 10(b)), and the electrolyte may leak through the via conductors 36a, 36b formed in the via holes 31x, 31y to the transparent electrode layer 21 and the counter electrode. The voltage on layer 40 can be extracted to each electrode pad 37a, 37c.

Furthermore, since there is no possibility of liquid leakage from the solid electrolyte layer 27, there is no need to provide a sealing material on the surface of the transparent base material 20 to prevent liquid leakage. By eliminating the need for a sealant in this way, the cell area I can be expanded, and the amount of power generated by the dye-sensitized solar cell 50 can be increased.

In addition, since the area where the sealing resin 47 and the transparent base material 20 overlap when viewed from above is extremely small, even if the dye-sensitized solar cell 50 is downsized, the transparent base material 20 can generate electricity. The area of the cell region I that contributes to this does not decrease significantly. Therefore, even when the dye-sensitized solar cell 50 is downsized, a sufficient effective power generation area can be ensured.
Furthermore, by drawing out the voltage through the via conductors 36a and 36b as described above, the dye-sensitized solar cell 50 is more efficient than when wiring for drawing out the voltage is provided on the side surface of the resin base material 31. Can be made smaller.

Furthermore, unlike a brittle material such as ceramic, the resin base material 31 has a certain degree of flexibility, so it is possible to suppress deterioration of the mechanical strength of the resin base material 31 due to each via hole 31x, 31y. .

By using the resin base material 31 that allows the via holes 31x and 31y to be formed easily and inexpensively by drilling, the dye It is possible to reduce the cost of the sensitized solar cell 50.
The method of using this dye-sensitized solar cell 50 is not particularly limited.

FIG. 11 is a cross-sectional view for explaining an example of how to use the dye-sensitized solar cell 50.

In the example of FIG. 11, it is assumed that the dye-sensitized solar cell 50 is mounted on a wiring board 60 built into an IoT device or the like. The wiring board 60 is made of resin such as glass epoxy resin, like the resin base material 31, and terminals 61 and 62 obtained by patterning a copper layer are provided on the surface thereof. Then, these terminals 61 and 62 are connected to each electrode pad 37a and 37c using solder 63.

By irradiating the dye-sensitized solar cell 50 with light L in this state, an electromotive force is generated, and an electronic device such as a sensor built into the IoT device can be operated by the electromotive force.

In such a method of use, the electrode pads 37a, 37c are heated when the solder 63 is melted during mounting, and the solid electrolyte layer 27 is thereby also heated. However, since the solid electrolyte layer 27 is more stable than a liquid electrolyte, it is less likely to be damaged by heat during mounting. Therefore, various parts for protecting the solid electrolyte layer 27 from damage due to heat are not required, and the dye-sensitized solar cell 50 can be downsized.

Furthermore, although the substrate on the opposite electrode side used in conventional dye-sensitized solar cells is a glass substrate, in this embodiment, a resin base material 31 is interposed between the transparent substrate 20 and each electrode pad 37a, 37c. There is. Therefore, the heat generated when connecting each electrode pad 37a, 37c and the wiring board 60 with the solder 63 becomes difficult to be transmitted to the transparent substrate 20, and it is possible to prevent the transparent substrate 20 from cracking due to the heat, and in turn, each electrode 37a, 37c can be prevented from being damaged.

Furthermore, since the resin base material 31 is formed from the same material as the wiring board 60, there is no significant difference in the amount of thermal expansion between the two, and the connection between the wiring board 60 and the dye-sensitized solar cell 50 is reliable. You can also maintain your sexuality.

Furthermore, by providing each electrode pad 37a, 37c to which the solder 63 is bonded to the dye-sensitized solar cell 50, the dye-sensitized solar cell 50 can be mounted on the wiring board 60 via the solder 63, and the two can be connected. This makes it possible to eliminate the need for connectors, etc.

(Second example)
In this example, a dye-sensitized solar cell that can generate more power than the first example will be described. FIGS. 12(a) to 13(b) are perspective views of the dye-sensitized solar cell according to the second example during manufacture. In addition, in these figures, the same elements as explained in the first embodiment are given the same reference numerals as in the first embodiment, and the explanation thereof will be omitted below.

First, as shown in FIG. 12(a), a transparent base material 20 having a transparent electrode layer 21 formed on the second main surface 20b is prepared. In this embodiment, triangular regions including the corners 20c and 20d of the transparent base material 20 become the first contact region CR ₁ and the second contact region CR ₂ , respectively. Although the size of the first contact region CR ₁ is not particularly limited, in this embodiment, the lengths Cx and Cy of one side of the first contact region CR ₁ are set to 0.5 mm to 1.5 mm, for example, 1 mm. The size of the second contact region _CR2 is also approximately the same. Then, a region including the entire portion of the transparent base material 20 excluding these contact regions CR ₁ and CR ₂ becomes a hexagonal cell region I.

Next, a slit 21s is formed in the transparent electrode layer 21 by irradiating the transparent electrode layer 21 with a laser along the edge of the first contact region CR ₁ , and the transparent electrode layer 21 in the first contact region CR ₁ is is separated from the transparent electrode layer 21 in the cell region I.

Subsequently, as shown in FIG. 12(b), an alcohol solution prepared from titanium alkoxide is applied onto the transparent electrode layer 21 in the cell region I, and the alcohol solution is heated and dried to remove reverse electrons. The movement prevention layer 22 is formed to have a thickness of about 5 nm to 0.1 μm. As in the first embodiment, the drying temperature in this step is 450°C to 650°C, for example about 550°C.

Next, as shown in FIG. 13(a), a slurry in which titanium oxide particles with a particle size of 5 nm to 50 nm are dispersed is screen printed onto the reverse electron transfer prevention layer 22 to a thickness of about 1 μm to 10 μm. The power generation layer 25 is formed by coating and heating it to remove organic components. The heating temperature of the slurry is 450° C. to 650° C., for example 550° C., and the drying time is 10 minutes to 120 minutes, for example about 30 minutes. Although the slurry is not particularly limited, in this example, PST-30NRD, which is a titanium oxide paste manufactured by JGC Catalysts and Chemicals, is used as the slurry, as in the first embodiment.

Thereafter, the transparent base material 20 is immersed in an organic solution containing a dye, and the dye is adsorbed onto the surface of the semiconductor particles constituting the power generation layer 25. As the organic solution, as in the first example, an organic solution is used in which CYC-B11 (K) is added as a dye to an organic solvent in which acetonitrile and t-butanol are mixed at a volume ratio of 1:1. . Note that the concentration of the dye in the organic solvent is 0.1 mM to 1 mM, for example 0.2 mM. Then, the transparent base material 20 is immersed in the organic solution for 1 hour to 12 hours, for example 4 hours, while keeping the organic solution at a temperature of 0° C. to 80° C., for example, 50° C., so that the dye is adsorbed to the power generation layer 25. That's fine.

Next, as shown in FIG. 13(b), 0.1 μL to 50 μL, for example 20 μL, of the solid electrolyte precursor 26 is dropped onto the power generation layer 25 to impregnate the power generation layer 25 with the solid electrolyte precursor 26. As the solid electrolyte precursor 26, for example, a liquid obtained by uniformly mixing each of iodine, 1,3-dimethylimidazolium iodide (DMII), acetonitrile, and polyethylene oxide having a molecular weight of 1 million is used.

Then, the power generation layer 25 is heated to volatilize excess acetonitrile contained in the solid electrolyte precursor 26, and the solid electrolyte precursor 26 on the power generation layer 25 becomes a solid electrolyte layer 27. Note that the heating temperature of the power generation layer 25 is 50°C to 150°C, for example 100°C. The heating time is 1 minute to 60 minutes, for example 30 minutes. After that, the power generation layer 25 is returned to room temperature.
With the above steps, the processing for the transparent base material 20 is completed. Next, a wiring board used together with this transparent base material 20 will be explained.

FIGS. 14(a) and 14(b) are perspective views of the wiring board 45 used in this embodiment. In FIGS. 14A and 14B, the same elements as described in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the explanation thereof will be omitted below.

Further, the wiring board 45 is manufactured in the same process as described in the first embodiment with reference to FIGS. Only the shape of is different from the first embodiment.

FIG. 14A is a perspective view of the wiring board 45 with the second main surface 31b of the resin base material 31 facing up.

As shown in FIG. 14A, in this embodiment as well, a first contact region CR ₁ and a second contact region CR ₂ are provided outside the cell region I. Among these, the first contact region CR ₁ is provided so as to include the corner portion 31c of the resin base material 31, and the first via conductor 36a is provided in the first contact region CR ₁ .

Further, the second contact region CR ₂ is provided to include the corner portion 31d of the resin base material 31, and the second via conductor 36b is provided in the second contact region CR ₂ .

FIG. 14(b) is a perspective view of the wiring board 45 with the first main surface 31a of the resin base material 31 facing upward.

As shown in FIG. 14(b), the counter electrode layer 40 in the second contact region _CR2 is separated from the cell region I by patterning to form a triangular connection pad 40a.

FIG. 15(a) is a cross-sectional view taken along line EE in FIG. 14(a). As shown in FIG. 15(a), the first via conductor 36a is formed in the first via hole 31x of the resin base material 31 similarly to the first embodiment. Further, the counter electrode layer 40 is formed by forming each of a copper layer 37, a gold layer 38, and a catalyst layer 39 in this order on the first main surface 31a of the resin base material 31, as in the first embodiment. Become.

Further, FIG. 15(b) is a cross-sectional view taken along line FF in FIG. 14(a).

As shown in FIG. 15(b), the first electrode pad 37a is formed by patterning a copper layer 37 as in the first embodiment, and a gold layer 38 is formed thereon by flash plating.

FIG. 15(c) is a cross-sectional view taken along line GG in FIG. 14(a).

As shown in FIG. 15(c), the second via conductor 36b is formed in the second via hole 31y of the resin base material 31, similar to the first embodiment.

The subsequent steps will be explained with reference to FIGS. 16 to 18. 16 to 18 are cross-sectional views of the dye-sensitized solar cell according to this example during manufacture.

First, as shown in FIG. 16, the aforementioned transparent base material 20 is prepared again, and silver paste is applied as a conductive layer 43 on the transparent electrode layer 21 in the second contact region _CR2 . In order to prevent the conductive layer 43 and the solid electrolyte layer 27 from being electrically short-circuited, a space S is provided between the solid electrolyte layer 27 and the conductive layer 43 in this example. Conductive layers 43 are formed at intervals.

Next, an ultraviolet curable resin is applied onto the transparent electrode layer 21 in the first contact region CR ₁ , and then the ultraviolet curable resin is irradiated with ultraviolet rays and cured, thereby forming the insulating layer 44.

Note that the insulating layer 44 is also formed between the solid electrolyte layer 27 and the conductive layer 43, so that the solid electrolyte layer 27 and the conductive layer 43 are insulated by the insulating layer 44.

Then, the wiring board 45 is arranged above the transparent base material 20, and the solid electrolyte layer 27 of the transparent base material 20 and the first main surface 31a of the resin base material 31 are made to face each other.

Next, as shown in FIG. 17, the transparent base material 20 and the resin base material 31 are pasted together and heated to a temperature of about 50°C. As a result, the conductive layer 43 is solidified, and the second via conductor 36b and the transparent electrode layer 21 are connected via the conductive layer 43.

Note that, as described in the first embodiment, in order to prevent air bubbles from entering between the transparent base material 20 and the wiring board 45, it is preferable to perform this step in a vacuum or a reduced pressure atmosphere.

Furthermore, by pasting the transparent base material 20 and the resin base material 31 together in this way, each of the transparent electrode layer 21, the power generation layer 25, the solid electrolyte layer 27, and the counter electrode layer 40 can be seen in plan view in the cell region I. It will overlap.
FIG. 19(a) is a cross-sectional view taken along line HH in FIG. 17.

As shown in FIG. 19(a), in the cell region I, a transparent electrode layer 21, a solid electrolyte layer 27, and a counter electrode layer 40 are each formed, and the transparent base material 20 is formed as in the first embodiment. An electromotive force is generated in the power generation layer 25 in the cell region I by the light incident thereon. The transparent electrode layer 21 below the power generation layer 25 functions as a negative electrode, and the counter electrode layer 40 above the power generation layer 25 functions as a positive electrode.

Further, as in the first embodiment, in the cell region I, the side surfaces 20s and 25s of the transparent base material 20 and the power generation layer 25 are located on the same plane P, and compared to the case where the side surface 25s is set back from the side surface 20s. Also, the amount of light received by the power generation layer 25 increases.
On the other hand, FIG. 19(b) is a cross-sectional view taken along line JJ in FIG. 17.

As shown in FIG. 19(b), in the first contact region _CR1 , the counter electrode layer 40 and the first via conductor 36a are connected, and the positive voltage of the counter electrode layer 40 is applied to the resin base material 31. is pulled out to the second main surface 31b side. Moreover, the insulating layer 44 interposed between the transparent electrode layer 21 and the counter electrode layer 40 can suppress electrical short-circuiting between the first via conductor 36a and the transparent electrode layer 21. In particular, in this example, since the slits 21s are formed in the transparent electrode layer 21, it is possible to further reduce the possibility that the transparent electrode layer 21 and the first via conductor 36a will be electrically short-circuited.

On the other hand, in the second contact region CR ₂ , the second via conductor 36 b is connected to the transparent electrode layer 21 via the connection pad 40 a and the conductive layer 43 . Thereby, the negative voltage of the transparent electrode layer 21 is drawn out to the second main surface 31b side of the resin base material 31 via the second via conductor 36b. Furthermore, by forming the insulating layer 44 between the connection pad 40a and the counter electrode layer 40 as in this example, it is possible to suppress electrical short circuit between the connection pad 40a and the counter electrode layer 40. becomes.

After this, as shown in FIG. 18, an ultraviolet curing resin is applied as a sealing resin 47 to each side surface of the transparent base material 20 and the resin base material 31. Then, the sealing resin 47 is cured by irradiation with ultraviolet rays, and the sealing resin 47 prevents moisture from entering the solid electrolyte layer 27 and the like.

Through the above steps, the basic structure of the dye-sensitized solar cell 70 according to this example is completed.

According to the present embodiment described above, as shown in FIG. 14(a), the first via conductor 36a is provided at one of the two corners 31c and 31d of the rectangular resin base material 31, and the first via conductor 36a is provided at the other corner. A second via conductor 36b is provided.

This makes it possible to secure a wider cell area I than in the first embodiment, and it becomes possible to increase the amount of power generation compared to the first embodiment.

In this example, the resin base material 31 is rectangular in plan view, but the planar shape of the resin base material 31 is made into a polygonal shape with five or more corners, and two of the corners are The first via conductor 36a and the second via conductor 36b may be provided as described above.

20 Transparent base material 21 Transparent electrode layer 22 Reverse electron transfer prevention layer 25 Power generation layer 26 Solid electrolyte precursor 27 Solid electrolyte layer 30 Double-sided copper clad base material 31 Resin base material 32 First copper foil 33 Second copper foil 36a First Via conductor 36b Second via conductor 37 Copper layer 37a First electrode pad 37c Second electrode pad 40 Counter electrode layer 43 Conductive layer 44 Insulating layer 45 Wiring board 47 Sealing resin 50 Dye-sensitized solar cell 60 Wiring board 70 dye-sensitized solar cells

Claims (8)

a transparent base material,
a transparent electrode layer provided on the transparent base material;
a power generation layer containing a dye provided on the transparent electrode layer;
a solid electrolyte layer provided on the power generation layer;
a counter electrode layer provided on the solid electrolyte layer;
a resin base material fixed to the upper surface of the counter electrode layer;
has
The resin base material has a first main surface fixed to the upper surface of the counter electrode layer, and a second main surface opposite to the first main surface,
A first via hole and a second via hole are formed in the resin base material,
a first via conductor formed in the first via hole and electrically connected to the counter electrode layer ;
a second via conductor formed in the second via hole and electrically connected to the transparent electrode layer ;
a first electrode pad provided on the second main surface and connected to the first via conductor;
further comprising a second electrode pad provided on the second main surface and connected to the second via conductor,
The first via hole and the second via hole are provided outside a cell region where each of the transparent electrode layer, the power generation layer, the solid electrolyte layer, and the counter electrode layer overlap in plan view,
the first via conductor is connected to the counter electrode layer in the first contact region outside the cell region;
the second via conductor is connected to the transparent electrode layer in the second contact region outside the cell region;
A dye-sensitized solar cell characterized in that the transparent electrode layer in the first contact region is separated from the transparent electrode layer in the cell region. The dye-sensitized solar cell according to claim 1, wherein the first via conductor and the second via conductor are provided at an edge of the resin base material. The resin base material is polygonal in plan view,
The dye-sensitized solar according to claim 1, wherein the first via conductor is provided at one of the two corners of the polygon, and the second via conductor is provided at the other corner. battery. an insulating layer provided on the transparent electrode layer in the first contact region;
further comprising a conductive layer provided on the transparent electrode layer in the second contact region,
In the first contact region, the counter electrode layer is provided on the insulating layer,
The dye-sensitized solar cell according to claim 1, wherein the transparent electrode layer and the second via conductor are connected to each other via the conductive layer in the second contact region. The conductive layer is provided at a distance from the solid electrolyte layer in plan view,
The dye-sensitized solar cell according to claim 4, wherein the insulating layer is also provided between the solid electrolyte layer and the conductive layer. The dye-sensitized solar cell according to claim 1, wherein a side surface of the power generation layer and a side surface of the transparent base material are in the same plane. a transparent base material,
a transparent electrode layer provided on the transparent base material;
a power generation layer containing a dye provided on the transparent electrode layer;
a solid electrolyte layer provided on the power generation layer;
a counter electrode layer provided on the solid electrolyte layer;
a resin base material fixed to the upper surface of the counter electrode layer;
has
The resin base material has a first main surface fixed to the upper surface of the counter electrode layer, and a second main surface opposite to the first main surface,
A first via hole and a second via hole are formed in the resin base material,
a first via conductor formed in the first via hole and electrically connected to the counter electrode layer ;
a second via conductor formed in the second via hole and electrically connected to the transparent electrode layer ;
a first electrode pad provided on the second main surface and connected to the first via conductor;
further comprising a second electrode pad provided on the second main surface and connected to the second via conductor,
A cell region in which each of the transparent electrode layer, the power generation layer, the solid electrolyte layer, and the counter electrode layer overlaps in plan view has a rectangular shape in plan view,
A first region and a second region are provided in a region outside one side of the rectangular shape in plan view,
A conductive layer drawn out from the transparent electrode layer is provided in the second region and is electrically connected to the second via conductor, and the first via conductor extends to the first region and then connects to the counter electrode layer. A dye-sensitized solar cell characterized by electrical conductivity. The dye-sensitized solar cell according to claim 7, wherein the resin base material is a glass epoxy resin.

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