WO2020203443A1

WO2020203443A1 - Dye-sensitized solar cell

Info

Publication number: WO2020203443A1
Application number: PCT/JP2020/012904
Authority: WO
Inventors: 福島岳行; 染井秀徳
Original assignee: 太陽誘電株式会社
Priority date: 2019-03-29
Filing date: 2020-03-24
Publication date: 2020-10-08
Also published as: JP2020167300A; JP7369538B2

Abstract

A dye-sensitized solar cell according to the present invention is characterized by comprising: a transparent base material; a transparent electrode layer that is provided on the transparent base material; a power generation layer that is provided on the transparent electrode layer, while containing a dye; a solid electrolyte layer that is provided on the power generation layer; a counter electrode layer that is provided on the solid electrolyte layer; and a resin base material that is firmly bonded to the upper surface of the counter electrode layer.　

Description

Dye-sensitized solar cell

The present invention relates to a dye-sensitized solar cell.

Dye-sensitized solar cells are attracting attention as new solar cells to replace silicon-based solar cells. Dye-sensitized solar cells can efficiently generate electricity even in low-light environments such as indoors and 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 the dye-sensitized solar cell on the wiring board built in the IoT device, it is possible to drive an electronic device such as a sensor in the IoT device with the electric power of the dye-sensitized solar cell.

Various solar cells have been proposed so far that are supposed to be mounted on a wiring board, but there is room for improvement in all of them.

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

Further, a technique of providing an electrode pad on a translucent base material included in a dye-sensitized solar cell and connecting the electrode pad and a wiring substrate with solder is also disclosed (Patent Document 2). In this technique, heat is easily transferred to the dye-sensitized solar cell, so that the characteristics may deteriorate.

Japanese Unexamined Patent Publication No. 2010-80122 Japanese Unexamined Patent Publication No. 2011-243298

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 the power generation. It is characterized by having a solid electrolyte layer provided on the 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 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 the second via conductor. A second via conductor formed in the via hole and electrically connected to the counter electrode layer, and a first electrode pad provided on the second main surface and connected to the first via conductor. It may further have 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 on the edge of the resin base material.

In the dye-sensitized solar cell, the resin base material is polygonal in a plan view, the first via conductor is provided on one of the two corners of the polygon, and the second via conductor is provided on the other. A via conductor may be provided.

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

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

In the dye-sensitized solar cell, the solid electrolyte layer is provided with a size that fits in the cell region in a plan view, and the insulating layer provided on the transparent electrode layer in the first contact region and the said. It further has a conductive layer provided on the transparent electrode layer in the second contact region, and in the first contact region, the counter electrode layer is provided on the insulating layer, and the second contact electrode layer is provided. 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 a plan view, and the insulating layer may also be provided between the solid electrolyte layer and the conductive layer. Good.

In the 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, the side surface of the power generation layer and the 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 capable of increasing the amount of power generation.

(A) and (b) are perspective views (No. 1) during the manufacture of the dye-sensitized solar cell according to the first embodiment. (A) and (b) are perspective views (No. 2) during the production of the dye-sensitized solar cell according to the first embodiment. (A) to (c) are cross-sectional views (No. 1) of the wiring board according to the first embodiment during manufacturing. (A) to (c) are cross-sectional views (No. 2) during manufacturing of the wiring board according to the first embodiment. (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 turned up, and (b) is a cross section along the line BB of (a). It is a figure. It is a perspective view of the wiring board which concerns on 1st Example when the 1st main surface of a resin base material is turned up. It is a perspective view (No. 3) in the process of manufacturing the dye-sensitized solar cell which concerns on 1st Example. It is a perspective view (the 4) in the manufacturing process of the dye-sensitized solar cell which concerns on 1st Example. It is a perspective view (No. 5) in the process of manufacturing the dye-sensitized solar cell which concerns on 1st Example. (A) is a cross-sectional view taken along the line CC of FIG. 8, and (b) is a cross-sectional view taken along the line DD of FIG. It is sectional drawing for demonstrating an example of the use method of the dye-sensitized solar cell which concerns on 1st Example. (A) and (b) are perspective views (No. 1) during the production of the dye-sensitized solar cell according to the second embodiment. (A) and (b) are perspective views (No. 2) during the production of the dye-sensitized solar cell according to the first embodiment. (A) and (b) are perspective views of the wiring board used in this embodiment. (A) is a cross-sectional view taken along the line EE of FIG. 14 (a), (b) is a cross-sectional view taken along the line FF of FIG. 14 (a), and (c) is a cross-sectional view taken along the line EF of FIG. 14 (a). ) Is a cross-sectional view taken along the line GG. It is a perspective view (No. 3) in the process of manufacturing the dye-sensitized solar cell which concerns on 2nd Example. It is a perspective view (the 4) in the manufacturing process of the dye-sensitized solar cell which concerns on 2nd Example. It is a perspective view (No. 5) in the process of manufacturing the dye-sensitized solar cell which concerns on 2nd Example. (A) is a cross-sectional view taken along the line HH of FIG. 17, and (b) is a cross-sectional view taken along the line JJ of FIG.

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

First, as shown in FIG. 1A, a transparent base material 20 having a first main surface 20a and a second main surface 20b facing each other is prepared. Of these main surfaces, the first main surface 20a is an incident surface on which light is incident under 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. Instead of the ITO layer, any one 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 transparent. It may 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 thereof 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. The thickness Az of the transparent base material 20 is 0.1 mm to 3.0 mm, for example, 1.1 mm. 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 cause 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 drying may be performed at a temperature of 450 ° C. to 650 ° C., for example, about 550 ° C.

The cell region I is a region in which the solar cell is formed on the transparent base material 20. Further, the region adjacent to the cell region I becomes a peripheral region II in which a via conductor for drawing electric power from the solar cell is later formed.

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

Subsequently, as shown in FIG. 2A, a slurry in which titanium oxide particles having a particle size of 5 nm to 50 nm are dispersed is placed on the reverse electron transfer prevention layer 22 by a screen printing method to a thickness of about 1 μm to 10 μm. The power generation layer 25 is formed by applying the 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.

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

After that, the transparent base material 20 is immersed in an organic solution containing a dye, and the dye is adsorbed on the surface of the semiconductor particles constituting the power generation layer 25. The organic solution and immersion conditions are not particularly limited. For example, an organic solvent prepared by mixing acetonitrile and t-butanol in a volume ratio of 1: 1 is prepared, and CYC-B11 (K) as a dye is added to the organic solvent at a concentration of 0.1 mM to 1 mM, for example, 0.2 mM. The added organic solution can be used in this step. Then, while keeping the organic solution at 0 ° C. to 80 ° C., for example, 50 ° C., the transparent base material 20 is immersed in the organic solution for 1 hour to 12 hours, for example, 4 hours to adsorb the dye on the power generation layer 25. Just do it.

Further, the dye is not limited to the above, and the metal complex dye or the organic dye may be adsorbed on the power generation layer 25. Among these, examples of the metal complex dye include transition metal complexes such as ruthenium-cis-diaqua-bipyridyl complex, ruthenium-tris complex, ruthenium-bis complex, osmium-tris complex, and osmium-bis complex. Zinc-tetra (4-carboxyphenyl) porphyrin and iron-hexacianide complex 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 dyes, merocyanine dyes, xanthene dyes, carbazole compound dyes and the like.

Next, the process shown in FIG. 2B will be described. 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 so as to be uniform. Next, the solid electrolyte precursor 26 is dropped onto the power generation layer 25 by 0.1 μL to 50 μL, for example, 20 μL, and the power generation layer 25 is impregnated with the solid electrolyte precursor 26. Then, the power generation layer 25 is heated to 50 ° C. to 150 ° C., for example, 100 ° C., and this state is maintained for 1 minute to 60 minutes, for example, 30 minutes to volatilize the excess acetonitrile contained in the solid electrolyte precursor 26. The solid electrolyte precursor 26 on the power generation layer 25 is designated as the solid electrolyte layer 27. After that, the power generation layer 25 is returned to room temperature.

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

Further, the material of the solid electrolyte layer 27 is not limited to the above, and an organic semiconductor material such as a molten salt containing a redox pair, an oxadiazole compound, and a pyrazoline compound 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.
This completes the treatment for the transparent base material 20.

In this embodiment, a dye-sensitized solar cell is manufactured by joining a wiring board to the transparent base material 20. Therefore, the manufacturing method of the wiring board will be described next.

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

First, the double-sided copper-clad base material 30 shown in FIG. 3A is prepared. The double-sided copper-clad base material 30 has a first copper foil 32 pressed onto the first main surface 31a of the resin base material 31 by hot pressing, and has a second main surface 31b facing the first main surface 31a. It can be produced by crimping the copper foil 33 of No. 2 by a hot press.

The resin base material 31 is not particularly limited, but in this example, a glass epoxy substrate obtained by impregnating a glass woven fabric with a heat-resistant epoxy resin is used as the resin base material 31. The polyimide film may be used as the resin base material 31. The thickness of the resin base material 31 is 0.1 mm to 3.2 mm, for example, 1 μm. Further, the thickness of each of the copper foils 32 and 33 is not particularly limited. As an example, the thickness of each of the copper foils 32 and 33 is 18 μm to 200 μm, for example 35 μm.

Subsequently, as shown in FIG. 3B, the resin base material 31 is formed with the first via hole 31x 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. 3C, an electroless copper plating layer is formed on the inner surface of the first via hole 31x and the surfaces of the copper foils 32 and 33, and an electrolytic copper plating layer is further formed on the electroless copper plating layer. To do. The total 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 the first via conductor 36a, and the copper foils 32 and 33 and these copper plating layers are used as the copper layer 37.

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

Subsequently, as shown in FIG. 4B, the gold layer 38 was placed on the copper layer 37, the first electrode pad 37a, and the first wiring 37b by electroless plating to form a gold layer 38 of 0.01 μm to 0.05 μm. For example, it is formed to have a thickness of about 0.03 μm. The plating method for forming the gold layer 38 having such a thin thickness is also called flash plating.

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

The titanium layer in the catalyst layer 39 functions as an adhesion layer, and its thickness is about 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 a thickness of 0.01 μm to 0.3 μm, for example, about 0.05 μm.

From the above, 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 when the second main surface 31b of the resin base material 31 is turned up. The above-mentioned FIG. 4 (c) corresponds to a cross-sectional view taken along the line AA of 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. Then, 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 having a side length of 1 mm to 6 mm, for example, 5 mm in a plan view. The shape of the second electrode pad 37c is similar to this.
5 (b) is a cross-sectional view taken along the line BB of FIG. 5 (a).

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

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

As shown in FIG. 6, the above-mentioned 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 are regions corresponding to the peripheral region II (see FIG. 2B) outside the cell region I, and power is supplied from the cell region I via the via

conductors

36a and 36b. This is the area to take out.

The counter electrode layer 40 is formed in the first contact region CR ₁ , whereas the 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 CR ₂ .

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

The subsequent steps will be described with reference to FIGS. 7 to 9. 7 to 9 are perspective views during the production of the dye-sensitized solar cell according to the present embodiment.

First, as shown in FIG. 7, the above-mentioned transparent base material 20 is prepared again. Then, a silver paste is applied as the conductive layer 43 on the transparent electrode layer 21 in the second contact region CR ₂ . 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 them to form the conductive layer 43 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 to be cured to form an insulating layer 44. In this example, the solid electrolyte layer 27 and the conductive layer 43 are insulated by the insulating layer 44 by forming the insulating layer 44 also in the space S between the solid electrolyte layer 27 and the conductive layer 43.

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 face each other.

Next, as shown in FIG. 8, the transparent base material 20 and the resin base material 31 are laminated 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.

It is preferable to perform this step in a vacuum or a reduced pressure atmosphere in order to prevent air bubbles from being mixed between the transparent substrate 20 and the wiring substrate 45.

Further, by laminating the transparent base material 20 and the resin base material 31 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 in the cell region I is viewed in a plan view. It will overlap.
FIG. 10A is a cross-sectional view taken along the line CC of FIG.

As shown in FIG. 10A, in the cell region I, the counter electrode layer 40 is fixed to the first main surface 31a of the resin base material 31, and the solid electrolyte layer 27 and the transparent electrode layer 21 are beneath the counter electrode layer 40. And are formed. Then, when light is incident on 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 the potential difference due to the electromotive force is the transparent electrode layer 21 and the counter electrode layer. Occurs between 40 and 40. In this example, the transparent electrode layer 21 serves as a negative electrode, and the counter electrode layer 40 serves as 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, and 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 surface P. As a result, the amount of light received by the power generation layer 25 increases as compared with the case where the power generation layer 25 is formed on the transparent base material 20 so that the side surface 25s recedes from the side surface 20s, and the amount of power generation in the cell region I is increased. Is possible.
On the other hand, FIG. 10B is a cross-sectional view taken along the line DD of FIG.

As shown in FIG. 10B, in the first contact region CR ₁ , the counter electrode layer 40 and the first via conductor 36a are connected, and the positive voltage of the counter electrode layer 40 is the resin base material 31. It is pulled out to the second main surface 31b side of the above. 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 the first via conductor 36a and the transparent electrode layer 21 from being electrically short-circuited. Can be prevented with.

On the other hand, in the second contact region CR ₂ , 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 the second via conductor 36b. It is pulled out to the second main surface 32b side of the resin base material 31 via.

After that, as shown in FIG. 9, an ultraviolet curable resin is applied as a sealing resin 47 to each side surface of the transparent base material 20 and the resin base material 31, and then 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. The ultraviolet curable resin may be applied so as to cover a part of the second main surface 31b of the resin base material 31 to form the sealing resin 47.

From the above, the basic structure of the dye-sensitized solar cell 50 according to this embodiment is completed.

In the dye-sensitized solar cell 50, a solid electrolyte layer 27 having no possibility of liquid leakage is used without using a liquid electrolyte. Therefore, there is no possibility that the electrolyte leaks from the via

holes

31x and 31y (see FIG. 10B), and the transparent electrode layer 21 and the counter electrode are passed through the via

conductors

36a and 36b formed in the via

holes

31x and 31y. The voltage of the layer 40 can be drawn out to the

electrode pads

37a and 37c, respectively.

Further, since there is no possibility that the solid electrolyte layer 27 leaks, it is not necessary to provide a sealing material on the surface of the transparent base material 20 to prevent the leak. By eliminating the need for the sealing material in this way, the cell region I can be expanded, and the amount of power generated by the dye-sensitized solar cell 50 can be increased.

Further, since the area where the sealing resin 47 and the transparent base material 20 overlap when viewed in a plan view is extremely small, even when the dye-sensitized solar cell 50 is miniaturized, the transparent base material 20 generates electricity. The area of the cell region I that contributes to the above does not decrease significantly. Therefore, an effective power generation area can be sufficiently secured even when the dye-sensitized solar cell 50 is miniaturized.
Moreover, by drawing out the voltage through the via

conductors

36a and 36b as described above, the dye-sensitized solar cell 50 is compared with the case where the wiring for drawing out the voltage is provided on the side surface of the resin base material 31. It can be miniaturized.

Further, unlike a brittle material such as ceramic, the resin base material 31 has a certain degree of flexibility, so that deterioration of the mechanical strength of the resin base material 31 due to the via

holes

31x and 31y can be suppressed. ..

By using the resin base material 31 capable of easily and inexpensively forming the via

holes

31x and 31y by drilling, the dye is compared with the case where the ceramic base material is used instead of the resin base material 31. The cost of the sensitized solar cell 50 can be reduced.
The method of using the 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 the wiring board 60 built in the IoT device or the like. The wiring board 60 is formed of a resin such as a 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 and the

electrode pads

37a and 37c are connected by solder 63.

In this state, the dye-sensitized solar cell 50 is irradiated with light L to generate an electromotive force, and an electronic device such as a sensor built in the IoT device can be operated with the electromotive force.

In such a usage method, the

electrode pads

37a and 37c are heated when the solder 63 is melted at the time of mounting, whereby the solid electrolyte layer 27 is also heated. However, since the solid electrolyte layer 27 is more stable than the liquid electrolyte, it is less likely to be damaged by heat during mounting. Therefore, various parts for protecting the solid electrolyte layer 27 from heat damage become unnecessary, and the dye-sensitized solar cell 50 can be miniaturized.

Further, the substrate on the counter electrode side used in the conventional dye-sensitized solar cell is a glass substrate, but in this embodiment, the resin substrate 31 is interposed between the transparent substrate 20 and the

electrode pads

37a and 37c. There is. Therefore, it becomes difficult for the heat when connecting the

electrode pads

37a and 37c and the wiring board 60 with the solder 63 to be transferred to the transparent substrate 20, and it is possible to prevent the transparent substrate 20 from cracking due to the heat, and eventually the

electrodes

37a and 37c. Can be prevented from being damaged.

Further, since the resin base material 31 is formed of 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 reliability between the wiring board 60 and the dye-sensitized solar cell 50 Sex can also be maintained.

Further, since the

electrode pads

37a and 37c to which the solder 63 is bonded are provided on 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 both are connected. It is possible to eliminate the need for a connector or the like.

(Second Example)
In this embodiment, a dye-sensitized solar cell capable of increasing the amount of power generation as compared with the first embodiment will be described. 12 (a) to 13 (b) are perspective views during the manufacturing of the dye-sensitized solar cell according to the second embodiment. In these figures, the same elements as described in the first embodiment are designated by the same reference numerals as those described in the first embodiment, and the description thereof will be omitted below.

First, as shown in FIG. 12A, a transparent base material 20 having a transparent electrode layer 21 formed on the second main surface 20b is prepared. In this embodiment, the triangular regions including the

corners

20c and 20d of the transparent base material 20 are the first contact region CR ₁ and the second contact region CR ₂ , respectively. The size of the first contact region CR ₁ is not particularly limited, but in this embodiment, the lengths Cx and Cy of one side of the _first contact region CR ₁ are 0.5 mm to 1.5 mm, for example, 1 mm. The size of the second contact region CR ₂ is also about the same. Then, the region including all of the transparent base material 20 in the portion excluding these contact regions CR ₁ and CR ₂ becomes the hexagonal cell region I.

Next, the transparent electrode layer 21 is irradiated with a laser along the edge of the first contact region CR ₁ to form slits 21s in the transparent electrode layer 21, and the transparent electrode layer 21 in the first contact region CR ₁ is formed. Is separated from the transparent electrode layer 21 in the cell region I.

Subsequently, as shown in FIG. 12B, 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 cause reverse electrons. The movement prevention layer 22 is formed to have a thickness of about 5 nm to 0.1 μm. Similar to 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. 13A, a slurry in which titanium oxide particles having a particle size of 5 nm to 50 nm are dispersed is placed on the reverse electron transfer prevention layer 22 by a screen printing method to a thickness of about 1 μm to 10 μm. The power generation layer 25 is formed by applying the 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. The slurry is not particularly limited, but 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.

After that, the transparent base material 20 is immersed in an organic solution containing a dye, and the dye is adsorbed on the surface of the semiconductor particles constituting the power generation layer 25. As the organic solution, an organic solution prepared by adding CYC-B11 (K) as a dye to an organic solvent obtained by mixing acetonitrile and t-butanol in a volume ratio of 1: 1 is used as in the first embodiment. .. The concentration of the dye in the organic solvent is 0.1 mM to 1 mM, for example, 0.2 mM. Then, while keeping the organic solution at 0 ° C. to 80 ° C., for example, 50 ° C., the transparent base material 20 is immersed in the organic solution for 1 hour to 12 hours, for example, 4 hours to adsorb the dye on the power generation layer 25. Just do it.

Next, as shown in FIG. 13B, 0.1 μL to 50 μL, for example, 20 μL of the solid electrolyte precursor 26 is dropped onto the power generation layer 25, and the power generation layer 25 is impregnated with the solid electrolyte precursor 26. As the solid electrolyte precursor 26, for example, a solution in which iodine, 1,3-dimethylimidazolium iodide (DMII), acetonitrile, and polyethylene oxide having a molecular weight of 1 million are uniformly mixed is used.

Then, the power generation layer 25 is heated to volatilize the excess acetonitrile contained in the solid electrolyte precursor 26, and the solid electrolyte precursor 26 on the power generation layer 25 is designated as the solid electrolyte layer 27. The heating temperature of the power generation layer 25 is 50 ° C. to 150 ° C., for example, 100 ° C. The heating time is 1 to 60 minutes, for example, 30 minutes. After that, the power generation layer 25 is returned to room temperature.
This completes the treatment for the transparent base material 20. Next, the wiring board used together with the transparent base material 20 will be described.

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 described in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted below.

Further, the wiring board 45 is manufactured in the same process as described with reference to FIGS. 3 (a) to 4 (c) in the first embodiment, and the positions of the via

conductors

36a and 36b and the counter electrode layer 40 are formed. Only the shape of is different from the first embodiment.

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

As shown in FIG. 14A, the first contact region CR ₁ and the second contact region CR ₂ are provided outside the cell region I in this embodiment as well. Of 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 so as 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. 14B is a perspective view of the wiring board 45 when the first main surface 31a of the resin base material 31 is facing up.

As shown in FIG. 14B, the counter electrode layer 40 in the second contact region CR ₂ 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 the line EE of FIG. 14 (a). As shown in FIG. 15A, the first via conductor 36a is formed in the first via hole 31x of the resin base material 31 as in the first embodiment. Further, in the counter electrode layer 40, the copper layer 37, the gold layer 38, and the catalyst layer 39 are each formed 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 the line FF of FIG. 14 (a).

As shown in FIG. 15B, 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 on the copper layer 37 by flash plating.

Then, FIG. 15 (c) is a cross-sectional view taken along the line GG of FIG. 14 (a).

As shown in FIG. 15C, the second via conductor 36b is formed in the second via hole 31y of the resin base material 31 as in the first embodiment.

The subsequent steps will be described with reference to FIGS. 16 to 18. 16 to 18 are cross-sectional views of the dye-sensitized solar cell according to the present embodiment during manufacturing.

First, as shown in FIG. 16, the above-mentioned transparent base material 20 is prepared again, and silver paste is applied as the conductive layer 43 on the transparent electrode layer 21 in the second contact region CR ₂ . In this example, 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, and the solid electrolyte layer 27 is used. The conductive layer 43 is 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 to be cured to form an insulating layer 44.

The insulating layer 44 is also formed between the solid electrolyte layer 27 and the conductive layer 43, whereby the solid electrolyte layer 27 and the conductive layer 43 are insulated by the insulating layer 44.

Next, as shown in FIG. 17, the transparent base material 20 and the resin base material 31 are laminated 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.

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

Further, by laminating the transparent base material 20 and the resin base material 31 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 in the cell region I is viewed in a plan view. It will overlap.
FIG. 19A is a cross-sectional view taken along the line HH of FIG.

As shown in FIG. 19A, each of the transparent electrode layer 21, the solid electrolyte layer 27, and the counter electrode layer 40 is formed in the cell region I, and the transparent base material 20 is formed as in the first embodiment. Electromotive force is generated in the power generation layer 25 in the cell region I by the light incident through the cell region I. Then, the transparent electrode layer 21 under 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 surface P, and the side surface 25s is retracted from the side surface 20s. Also, the amount of light received by the power generation layer 25 increases.
On the other hand, FIG. 19B is a cross-sectional view taken along the line JJ of FIG.

As shown in FIG. 19B, in the first contact region CR ₁ , the counter electrode layer 40 and the first via conductor 36a are connected, and the positive voltage of the counter electrode layer 40 is the resin base material 31. It is pulled out to the second main surface 31b side of the above. Further, the insulating layer 44 interposed between the transparent electrode layer 21 and the counter electrode layer 40 can prevent the first via conductor 36a and the transparent electrode layer 21 from being electrically short-circuited. In particular, in this example, since the slits 21s are formed in the transparent electrode layer 21, the possibility that the transparent electrode layer 21 and the first via conductor 36a are electrically short-circuited can be further reduced.

On the other hand, in the second contact region CR ₂ , the second via conductor 36b is connected to the transparent electrode layer 21 via the connection pad 40a and the conductive layer 43. As a result, the negative voltage of the transparent electrode layer 21 is drawn to the second main surface 31b side of the resin base material 31 via the second via conductor 36b. Further, 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 prevent the connection pad 40a and the counter electrode layer 40 from being electrically short-circuited. It becomes.

After that, as shown in FIG. 18, an ultraviolet curable 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 water from entering the solid electrolyte layer 27 and the like.

From the above, the basic structure of the dye-sensitized solar cell 70 according to this embodiment is completed.

According to the above-described embodiment, as shown in FIG. 14A, the first via conductor 36a is provided on one of the two

corners

31c and 31d of the rectangular resin base material 31, and the other. Is provided with a second via conductor 36b.

As a result, it is possible to secure a wider cell area I than in the first embodiment, and it is possible to increase the amount of power generation as compared with the first embodiment.

In this embodiment, the resin base material 31 has a rectangular shape in a plan view, but the plane shape of the resin base material 31 is made into a polygonal shape having five or more corners, and two of the corners are used. As described above, the first via conductor 36a and the second via conductor 36b may be provided.

Claims

With a transparent base material
A transparent electrode layer provided on the transparent base material and
A power generation layer containing a dye provided on the transparent electrode layer and
A solid electrolyte layer provided on the power generation layer and
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 and
A dye-sensitized solar cell characterized by having.
The resin base material has a first main surface fixed to the upper surface of the counter electrode layer and a second main surface which is an opposite surface of the first main surface.
A first via hole and a second via hole are formed on the resin base material,
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 second 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, and
The dye-sensitized solar cell according to claim 1, further comprising a second electrode pad provided on the second main surface and connected to the second via conductor.
The dye-sensitized solar cell according to claim 2, wherein the first via conductor and the second via conductor are provided on the edge of the resin base material.
The resin base material is polygonal in a plan view and is
The dye-sensitized solar according to claim 2, wherein the first via conductor is provided on one of the two corners of the polygon, and the second via conductor is provided on the other. battery.
The first via hole and the second via hole are characterized in that the transparent electrode layer, the power generation layer, the solid electrolyte layer, and the counter electrode layer are each provided outside the cell region where they overlap in a plan view. The dye-sensitized solar cell according to claim 2.
The first via conductor is connected to the counter electrode layer in the outer first contact region of the cell region.
The dye-sensitized solar cell according to claim 5, wherein the second via conductor is connected to the transparent electrode layer in the outer second contact region of the cell region.
An insulating layer provided on the transparent electrode layer in the first contact region and
Further having 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, and the counter electrode layer is provided.
The dye-sensitized solar cell according to claim 6, wherein in the second contact region, the transparent electrode layer and the second via conductor are connected via the conductive layer.
The conductive layer is provided at a distance from the solid electrolyte layer in a plan view.
The dye-sensitized solar cell according to claim 7, wherein the insulating layer is also provided between the solid electrolyte layer and the conductive layer.
The dye-sensitized solar cell according to claim 6, wherein 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 side surface of the power generation layer and the side surface of the transparent base material are in the same plane.