Solar battery

Abstract

To provide a solar battery with a vertical conductive connection structure having a high durability performance.SOLUTION: A solar battery comprises a plurality of units. Each unit contains: an electrode; a light absorption layer that is formed onto the electrode, and contains an electron capture agent and a coloring agent; and an opposite electrode that is arranged so as to be opposite to the electrode. In a space between a first unit and a second unit that are adjacent from the plurality of units, a vertical conductive sealing material conducting the first and second units is formed. The vertical conductive sealing material includes: a conductive part in which the electrode extended from the first unit and the opposite electrode extended from the second unit are opposite; and a non-conductive part in which the electrode that is extended from the first unit and the opposite electrode that is extended from the second unit are not opposite.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to solar cells. [Background technology]

[0002] As a photoelectric conversion element, solar cells have been attracting attention because they are inexpensive and have high photoelectric conversion efficiency. Solar cells are expected to be used as energy harvesting elements. Solar cells are sometimes used as modules in which multiple solar cell units are connected in series to increase the light receiving area. Here, in order to connect multiple units in series, the electrodes provided on each unit may be connected vertically using a conductive sealing material. A solar cell module with this structure is sometimes called a Z-type module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-093252 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional Z-type module structure, peeling of the sealing material can occur due to weak adhesion between the electrodes and the sealing material.

[0005] An object of the present disclosure is to provide a solar cell having a vertical conduction connection structure with high durability. [Means for solving the problem]

[0006] The solar cell of one embodiment includes a plurality of units. Each unit includes an electrode, a light absorbing layer formed on the electrode and containing an electron collector and a dye, and a counter electrode arranged opposite the electrode. Between adjacent first and second units among the plurality of units, a vertically conductive sealant is formed to electrically connect the first and second units, and the vertically conductive sealant has a conductive portion where the electrode extended from the first unit faces the counter electrode extended from the second unit, and a non-conductive portion where the electrode extended from the first unit does not face the counter electrode extended from the second unit. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a solar cell having a vertical conduction connection structure with high durability. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a solar cell according to an embodiment. [Diagram 2] FIG. 2 is a diagram for explaining the principle of power generation in one unit of the dye-sensitized solar cell. [Diagram 3] FIG. 3 is a plan view of the dye-sensitized solar cell as viewed from the first substrate side. [Figure 4] FIG. 4 is a cross-sectional view of the vertical conductive sealing material taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a plan view of the dye-sensitized solar cell in Modification 1 as viewed from the first substrate side. [Figure 6] FIG. 6 is a plan view of the vertical conductive sealing material of the second modification seen from the substrate side. [Figure 7] FIG. 7 is a cross-sectional view of the vertical conductive sealing material taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a diagram showing a comparison of the series resistance between a dye-sensitized solar cell having the electrode structure of Modification 2 and a dye-sensitized solar cell having a conventional electrode structure. [Figure 9]FIG. 9 is a diagram showing the results of a reliability test at 85° C. and 85% RH for a dye-sensitized solar cell having the electrode structure of the second modification. [Figure 10] FIG. 10 is a cross-sectional view showing an example of the arrangement interval of comb teeth between an electrode and a counter electrode inside a vertical conductive sealing material. [Figure 11] FIG. 11 is a cross-sectional view showing another example of the arrangement interval of the comb teeth of the electrode and the counter electrode inside the vertical conductive sealing material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a solar cell according to an embodiment. The solar cell is a dye-sensitized solar cell with a liquid electrolyte. The dye-sensitized solar cell 1 in FIG. 1 is a dye-sensitized solar cell module with a Z-type structure in which a plurality of dye-sensitized solar cell units U1, U2, U3, and U4 are connected in series. In FIG. 1, the number of units is four. The number of units is not limited to four.

[0010] As shown in Fig. 1, each of the units U1, U2, U3, and U4 of the dye-sensitized solar cell 1 is formed between a first substrate 11 and a second substrate 12. The first substrate 11 is a transparent substrate such as a glass substrate. The second substrate 12 is disposed so as to face the first substrate 11. Like the first substrate 11, the second substrate 12 is a transparent substrate such as a glass substrate.

[0011] An electrode 13 is formed at the position of each unit on the first substrate 11. The electrodes 13 are spaced apart such that there is no influence of leakage current between adjacent electrodes. The electrodes 13 are formed of a transparent conductive oxide film (TCO) such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO). Each electrode 13 is used as an anode electrode of the corresponding unit. The electrode 13 formed on one of the units U1 and U4, which are end units in the dye-sensitized solar cell 1, unit U4 in FIG. 1, is drawn out to the outside of the dye-sensitized solar cell 1. This drawn out electrode 13 is connected to a counter electrode 14 via a top-bottom conductive sealing material 19. This counter electrode 14 is drawn out to the outside of the dye-sensitized solar cell 1. A terminal 131 is formed on the drawn out counter electrode 14. A wiring is drawn out from the terminal 131. This wiring is connected to one end of a load (not shown). The terminal 131 may be formed on the electrode 13 drawn out to the outside.

[0012] A counter electrode 14 is formed at the position of each unit on the second substrate 12. The counter electrodes 14 are spaced apart such that there is no influence of leakage current between adjacent electrodes. The counter electrodes 14 are formed of a transparent conductive oxide film (TCO) such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) like the electrodes 13. Each counter electrode 14 is used as a cathode electrode of the corresponding unit. The counter electrode 14 formed in the other unit of the units U1 and U4, which are end units in the dye-sensitized solar cell 1, that is, the unit U1 in FIG. 1, is drawn out to the outside of the dye-sensitized solar cell 1. A terminal 141 is formed on the drawn out counter electrode 14. A wiring is drawn out from the terminal 141. This wiring is connected to the other end of a load (not shown). The terminal 141 may be formed on the side of the first substrate 11 by using a vertical conductive sealing material 19.

[0013] Here, either or both of the electrode 13 and the counter electrode 14 may be formed of a metal film such as copper or silver instead of TCO.

[0014] An electron transport layer 15 is formed on the electrode 13 that constitutes the anode electrode of each unit. The electron transport layer 15 is made of titanium oxide (TiO x ) a metal oxide film. The electron transport layer 15 may be provided to suppress loss due to the electrode 13 made of TCO, which has a higher resistance than metal. Furthermore, the formation of the electron transport layer 15 improves the adhesion of the light absorbing layer 16 to be further formed on the electron transport layer 15. As shown in FIG. 1, the electron transport layer 15 may be formed integrally with the electrode 13. In this case, the electron transport layer 15 in the unit U4 may be drawn out to the outside of the dye-sensitized solar cell 1, similar to the electrode 13 in the unit U4.

[0015] A light absorbing layer 16 is formed on each of the electron transport layers 15. The light absorbing layer 16 is a layer formed by adsorbing a dye to an electron collector. The electron collector is, for example, a fine oxide semiconductor, such as titanium oxide (TiO 2 ) is an aggregate. The dye is, for example, a ruthenium (Ru) dye (RU) (such as N719 dye). The electron collector is not limited to titanium oxide, but may be, for example, zinc oxide, tin oxide, tungsten oxide, niobium oxide, indium oxide, or a complex thereof. The dye is not limited to N719 dye. For example, N3 dye and BlackDye may be used as ruthenium-based dyes, and D149, xanthene, PVK, merocyanine, oxazine, or the like may be used as pure organic dyes.

[0016] A catalyst layer 17 is formed on the counter electrode 14 constituting the cathode electrode of each unit. The catalyst layer 17 is, for example, a platinum layer. The catalyst layer 17 may be formed integrally with the counter electrode 14. In this case, the catalyst layer 17 in the unit U1 may be extended to the outside of the dye-sensitized solar cell 1, similar to the counter electrode 14 in the unit U1.

[0017] An electrolyte solution 18 is filled between the light absorbing layer 16 and the catalyst layer 17 of each unit. As a solvent for the electrolyte solution 18, for example, acetonitrile, methoxyacetonitrile, ethylene carbonate, etc. can be used. As a solute for the electrolyte solution 18, for example, iodine (I 2 ), 1,2-dimethyl-3-n-propylimidazolium iodide (DMPImI), lithium iodide (LiI), 4-tert-butylpyridine (TBP), etc. may be used. As shown in FIG. 1, the electrolyte 18 is partitioned by vertical conductive sealants 19 provided at the boundary between each unit U1 and unit U2, the boundary between unit U2 and unit U3, and the boundary between unit U3 and unit U4. The vertical conductive sealants 19 are formed by incorporating a conductive material containing metal particles into a resin having excellent solvent resistance, such as an acrylic resin or an olefin resin. The vertical conductive sealants 19 bond the first substrate 11 and the second substrate 12 together, and are provided between the opposing electrodes to provide electrical continuity between the units. In other words, the vertical conductive sealants 19 provided at the boundary between unit U1 and unit U2 provide electrical continuity between the electrode 13 of unit U1 and the opposing electrode 14 of unit U2. The vertical conductive sealant 19 provided at the boundary between the units U2 and U3 provides electrical continuity between the electrode 13 of the unit U2 and the counter electrode 14 of the unit U3 via the electron transport layer 15 and the catalyst layer 17. The vertical conductive sealant 19 provided at the boundary between the units U3 and U4 provides electrical continuity between the electrode 13 of the unit U3 and the counter electrode 14 of the unit U4. As a result, the units U1, U2, U3, and U4 are connected in series.

[0018] An external sealing material 20 is formed between the electron transport layer 15 and the catalyst layer 17 at the outermost periphery of the dye-sensitized solar cell 1. The external sealing material 20 bonds the first substrate 11 and the second substrate 12 together and prevents the electrolyte 18 from leaking out to the outside. That is, the electrolyte 18 is sealed by the first substrate 11, the second substrate 12, the vertical conductive sealing material 19, and the external sealing material 20. The external sealing material 20 is, for example, a resin. The vertical conductive sealing material 19 is provided on the portion of the external sealing material 20 where the terminal 131 is to be formed. Thereby, the electrode 13 and the counter electrode 14 are electrically connected, and the terminal 131 can be formed on the side of the second substrate 12.

[0019] FIG. 2 is a diagram for explaining the power generation principle in one unit of a dye-sensitized solar cell. In the following example, the electron collector is titanium oxide (TiO 2 ), the dye is a ruthenium (Ru) dye, and the electrolyte 18 is an iodine (I) electrolyte.

[0020] First, when light is incident on the dye-sensitized solar cell, the light is absorbed by the dye 16a formed on the substrate. The dye 16a is excited by absorbing the light. The reaction formula is, for example, shown in the following formula (1). Ru → Ru + +e - (1)

[0021] Electrons emitted from the excited dye 16a (e - ) is, for example, a porous titanium oxide (TiO 2 The electrons injected into the electron collector 16b move to the electrode 13, which is an anode electrode.

[0022] On the other hand, electrons (e - The dye 16a that has lost the ion exchange function reacts with, for example, iodide ions (I - ) in electrolyte 18. - ) is an electron (e - ) to dye 16a, triiodide ions (I 3 -The reaction formula is shown in the following formulas (2) and (3). Ru+e - →Ru (2) 3I - →I 3 - +2e - (3)

[0023] The triiodide ion (I 3 - ) is transported from the cathode electrode 14 to the counter electrode 14 by electrons (e - At this time, a potential difference is generated between the counter electrode 14 and the electrode 13. If a load is connected between the counter electrode 14 and the electrode 13, the electrons that have moved to the electrode 13 will move through the load to the counter electrode 14. Then, the electrons that have reached the counter electrode 14 will be converted into triiodide ions (I 3 - ) is absorbed by the iodide ion (I 3 - ) is the iodide ion (I - ) The reaction formula is shown, for example, in the following formula (4). I 3 - +2e - →3I - (4)

[0024] The above-mentioned redox reaction is repeated to generate electricity in the dye-sensitized solar cell unit. For this redox reaction to occur, the energy level of the excited dye 16a must be higher than the energy level of the electron collector 16b, and the energy level of the ground dye 16a must be lower than the energy level of the electrolyte 18.

[0025] Fig. 3 is a plan view of the dye-sensitized solar cell 1 as viewed from the side of the first substrate 11. Fig. 4 is a cross-sectional view of the upper and lower conductive sealing material 19 taken along the line IV-IV in Fig. 3.

[0026] In the embodiment, as shown in Fig. 3 and Fig. 4, in a plurality of regions 19a (four in the figure) having a small cross-sectional area in each of the vertical conductive sealing materials 19, the electrode 13 and the counter electrode 14 face each other. Therefore, in the regions 19a, the electrode 13 and the counter electrode 14 are electrically connected via the vertical conductive sealing materials 19. Hereinafter, the regions 19a are referred to as conductive parts. On the other hand, in the regions other than the regions 19a, the electrode 13 and the counter electrode 14 are not opposed to each other. Therefore, in the regions other than the regions 19a, the electrode 13 and the counter electrode 14 are not electrically connected. Hereinafter, the regions other than the regions 19a are referred to as non-conductive parts.

[0027] 3 and 4, the electrode 13 and the counter electrode 14 are directly connected vertically via the vertical conductive sealant 19. In the region 19a of the vertical conductive sealant, an electron transport layer 15 and a light absorbing layer 16 may be formed on the electrode 13, and a catalyst layer 17 may be formed on the counter electrode 14.

[0028] In the process of preparing the first substrate 11 as an anode substrate, a porous TiO 2 was used as an electron collector 16b to form the light absorbing layer 16. 2 The dye 16a is adsorbed on the layer. At this time, minute dye residues are generated on the electrode 13. Due to these dye residues, the adhesion of the sealant formed on the electrode 13 tends to be weak. On the other hand, the adhesion of the sealant formed directly on the first substrate 11, which is a glass substrate, is stronger than that of the sealant formed on the electrode 13. More specifically, the applicant's experiments have revealed that 1) the adhesion is highest when the sealant is interposed between the first substrate 11 and the second substrate 12, 2) the adhesion is second highest when the sealant is interposed between the first substrate 11 and the counter electrode 14, 3) the adhesion is third highest when the sealant is interposed between the electrode 13 and the second substrate 12, and 4) the adhesion is lowest when the sealant is interposed between the electrode 13 and the counter electrode 14.

[0029] In order to conduct the electrode 13 and the counter electrode 14, it is necessary to make the electrode 13 and the counter electrode 14 face each other and interpose the vertical conductive sealant 19 between them. However, since it is only necessary for the electrode 13 and the counter electrode 14 to be conductive, it is not necessary to conduct the electrode 13 and the counter electrode 14 with a large area of ​​vertical conductive sealant. Therefore, in the embodiment, the electrode 13 and the counter electrode 14 have a comb shape with a part extending toward the region 19a, and are conducted through the vertical conductive sealant 19 at the conductive part at the position of the region 19a. With this configuration, a non-conductive part other than the region 19a can be formed between the first substrate 11 and the second substrate 12. Therefore, the area of ​​the region where the vertical conductive sealant is interposed between the electrode 13 and the counter electrode 14, which have weak adhesion, is reduced, and the adhesion of the sealant can be improved. This provides a vertical conductive connection structure with high durability.

[0030] Here, in FIG. 3 and FIG. 4, the electrode 13 and the counter electrode 14 are vertically conductive in four regions 19a in the vertical conductive sealant 19. The number of conductive parts is not limited to four. That is, the number of conductive parts may be one or more. If the number of conductive parts is increased, the region in which the vertical conductive sealant 19 is interposed between the electrode 13 and the counter electrode 14 increases, so that the adhesion decreases. On the other hand, if the number of conductive parts is increased, even if a conduction defect occurs in any of the conductive parts, the electrode 13 and the counter electrode 14 can be conductive as long as the conduction is ensured in another conductive part. In this way, a redundancy effect is expected by increasing the number of conductive parts. For this reason, it is desirable to set the number of conductive parts to an appropriate value taking into consideration the adhesion of the sealant and the redundancy effect.

[0031] [Variation 1] A modified example of the embodiment will be described below. In the example of FIG. 3, the units are arranged in one direction. The vertical conductive sealant 19 is provided at the boundary between the units. In this configuration, the terminal 131 is formed on one end of the second substrate 12, and the terminal 141 is formed on the other end of the second substrate 12. In contrast, as shown in FIG. 5, the units are folded back and arranged, so that the terminals 131 and 141 can be formed on the same end of the second substrate 12. In this case, the vertical conductive sealant 19 is also provided at the boundary between the units. The electrode 13 and the counter electrode 14 are vertically conductive in a region 19a of a very small cross-sectional area in the vertical conductive sealant 19.

[0032] [Variation 2] 4, in the embodiment, the length of the gap in the conductive portion is shorter than the gap in the non-conductive portion. Therefore, in the embodiment, different gaps are alternately present along the extending direction of the vertical conductive sealing material 19. The alternate presence of different gaps can be a factor that applies stress to the vertical conductive sealing material 19.

[0033] FIG. 6 is a plan view of the vertical conductive sealant 19 of the second modification seen from the first substrate 11 side. FIG. 7 is a cross-sectional view of the vertical conductive sealant 19 cut along the line VII-VII in FIG. 6. In the second modification as well, the electrode 13 and the counter electrode 14 have a comb-like shape. However, in the second modification, the extending portion of the electrode 13 and the extending portion of the counter electrode 14 do not completely overlap, but are shifted so as to overlap only partially. Therefore, the interval between the conductive parts in the second modification is shorter than the interval between the conductive parts in the embodiment. Furthermore, as shown in FIG. 7, in the second modification, a non-conductive part where the vertical conductive sealant 19 is interposed between the first substrate 11 and the counter electrode 14 or a non-conductive part where the vertical conductive sealant 19 is interposed between the second substrate 12 and the electrode 13 is provided between the conductive parts, instead of a non-conductive part where the vertical conductive sealant 19 is interposed between the first substrate 11 and the second substrate 12. Therefore, in the second modification, the change in the gap is more gradual than in the embodiment. Therefore, it is expected that the stress applied to the vertical conductive sealant 19 will be smaller. In addition, as described above, the adhesion when a sealant is interposed between the first substrate 11 and the counter electrode 14 and the adhesion when a sealant is interposed between the electrode 13 and the second substrate 12 are higher than the adhesion when a sealant is interposed between the electrode 13 and the counter electrode 14, so it is expected that a certain degree of adhesion of the vertical conductive sealant will also be ensured.

[0034] FIG. 8 is a diagram showing a comparison of the series resistance between a dye-sensitized solar cell having an electrode structure of the modified example 2 and a dye-sensitized solar cell having a conventional electrode structure. Here, the dye-sensitized solar cell having the conventional electrode structure has a structure in which the electrode 13 and the counter electrode 14 are connected solidly, that is, on the entire surface, via the upper and lower conductive sealing material 19. In FIG. 8, the series resistance of the dye-sensitized solar cell having the electrode structure of the modified example 2 is shown by "comb teeth", and the series resistance of the dye-sensitized solar cell having the conventional electrode structure of the modified example 2 is shown by "solid". The series resistance is one of the parameters that express the performance of the dye-sensitized solar cell, and corresponds to the sum of the internal resistances of the electrode, the light absorption layer, and the electrolyte of the dye-sensitized solar cell. In FIG. 8, the results are shown under lighting conditions of 200 lux, which is assumed to be indoor lighting, lighting conditions of 1000 lux, and lighting conditions of 1 sun (illuminance equivalent to direct sunlight in midsummer. Approximately 100,000 lux) which is assumed to be outdoor lighting.

[0035] 8, regardless of the lighting conditions, there is no significant difference in series resistance between the dye-sensitized solar cell with the electrode structure of Modification 2 and the dye-sensitized solar cell with the conventional electrode structure. This shows that even if the connection area between electrode 13 and counter electrode 14 is reduced, the performance does not change as long as there is electrical continuity.

[0036] FIG. 9 is a diagram showing the results of a reliability test at 85°C and 85% RH for a dye-sensitized solar cell having the electrode structure of Modification 2. In the test, a dye-sensitized solar cell having the electrode structure of Modification 2 was produced, and the change in maximum output when this dye-sensitized solar cell was exposed to conditions of a temperature of 85°C and a relative humidity of 85% for 500 hours (h) was measured. The horizontal axis of FIG. 9 is the elapsed time. The vertical axis of FIG. 9 is the maximum output Pmax. The maximum output Pmax is also known as one of the parameters that express the performance of a dye-sensitized solar cell. Here, in FIG. 9, the maximum output Pmax is shown as a ratio, with the value of the maximum output Pmax at 0 hours (h) set to 1.

[0037] 9, the maximum output Pmax hardly decreases even after 500 hours in the dye-sensitized solar cell having the electrode structure of Modification 2. This indicates that the dye-sensitized solar cell having the electrode structure of Modification 2 is a highly durable dye-sensitized solar cell that is less susceptible to leakage of the electrolyte 18 due to peeling of the sealing material.

[0038] In the above-described second modification, a dye-sensitized solar cell having a vertical conduction connection structure with higher durability than that of the embodiment is provided.

[0039] Here, in the example of FIG. 6, the region 19a is formed from end to end in the direction of the width W1 in the short side direction of the vertical conductive sealant 19. That is, the electrode 13 and the counter electrode 14 extend from end to end in the direction of the width W1 of the vertical conductive sealant 19. In reality, there may be variations and positional deviations when the vertical conductive sealant 19 is formed, and positional deviations when the first substrate 11 and the second substrate 12 are attached to each other. In order to ensure the connection resistance while taking these into consideration, it is desirable that the region 19a is formed inward by W2 in the direction of the width W1 of the vertical conductive sealant 19. W2 is, for example, 100 μm, and preferably 200 μm.

[0040] 10 is a cross-sectional view showing an example of the arrangement interval of the comb teeth of the electrode 13 and the counter electrode 14 inside the vertical conductive sealing material 19. Fig. 10 corresponds to the cross-sectional view taken along line VII-VII in Fig. 6.

[0041] Usually, the gap of the dye-sensitized solar cell 1 is adjusted by using a gap material. By mixing the conductive gap material into the top-bottom conductive sealing material 19, the gap of the dye-sensitized solar cell 1 is adjusted to a desired value, and a top-bottom conductive connection structure is obtained. Here, when considering the load when bonding the first substrate 11 and the second substrate 12, for example, a gap material having a particle size of d(μm)-d+α(μm) is used to form a gap of d(μm) and provide conductivity. Usually, α is about 1-2(μm).

[0042] Here, the longitudinal width of the upper and lower conductive sealing materials 19 of the conductive portion and the longitudinal width of the upper and lower conductive sealing materials 19 of the non-conductive portion do not necessarily need to be the same. However, from the viewpoint of maintaining a desired gap value and ensuring conductivity, it is desirable that the width of the conductive portion and the width of the non-conductive portion are equal to or larger than the grain size of the gap material. In the case of the configuration shown in FIG. 6, as shown in FIG. 10, four parts, namely, a conductive portion A, a non-conductive portion B, a conductive portion C, and a non-conductive portion D, are formed between adjacent electrodes. Since it is desirable that the widths of the conductive portion A, the non-conductive portion B, the conductive portion C, and the non-conductive portion D are equal to or larger than the grain size d of the gap material, it is desirable that the minimum interval between the comb teeth of the electrode 13 and the interval between the comb teeth of the counter electrode 14 are equal to or larger than 4d (μm).

[0043] FIG. 11 is a cross-sectional view showing another example of the arrangement interval of the teeth of the electrode 13 and the counter electrode 14 inside the vertical conductive sealing material 19. In FIG. 10, all the electrodes 13 and the counter electrode 14 are connected in series inside the vertical conductive sealing material 19. As described above, it is sufficient that the electrode 13 and the counter electrode 14 are connected at least at one point inside the vertical conductive sealing material 19. Therefore, as shown in FIG. 11, a structure may be used in which the arrangement interval between the electrode 13 and the counter electrode 14 is expanded to form four parts, a conductive part A, a non-conductive part B, a non-conductive part C, and a non-conductive part D, between adjacent electrodes. Even in this case, it is preferable that the conductive part A, the non-conductive part B, the non-conductive part C, and the non-conductive part D are each spaced apart by a distance equal to or greater than the particle diameter d of the gap material, so that the minimum interval between the teeth of the electrode 13 and the interval between the teeth of the counter electrode 14 are preferably 4d (μm) or more.

[0044] (Other variations) Other modified examples will be described. In the above-mentioned embodiment and modified examples, examples of application to a dye-sensitized solar cell with a liquid electrolyte are shown. In contrast, the configurations of the above-mentioned embodiment and modified examples can be applied to configurations other than the dye-sensitized solar cell with a liquid electrolyte. For example, the dye-sensitized solar cell may be a dye-sensitized solar cell with a solid electrolyte. In the case of a dye-sensitized solar cell with a solid electrolyte, the only difference is that a solid electrolyte layer is interposed between the light absorption layer 16 and the catalyst layer 17 of each unit, rather than the electrolyte 18. The solid electrolyte layer may be, for example, the electrolyte 18 gelled by a gelling agent or the like.

[0045] As a further modification, the configurations of the above-described embodiment and modification may be applied to various solar cells other than dye-sensitized solar cells such as perovskite solar cells, etc. For example, in the case of a perovskite solar cell, the solid electrolyte layer may be replaced with a perovskite crystal layer.

[0046] In the above-described embodiment and modified examples, the first substrate 11 and the second substrate 12 are transparent substrates such as glass substrates. In contrast, the first substrate 11 and the second substrate 12 may be flexible substrates. In this case, the configurations of the above-described embodiment and modified examples may be applied to a monolithic structure in which electrodes and the like are formed on only one of the first substrate 11 and the second substrate 12.

[0047] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made in the implementation stage without departing from the gist of the invention. In addition, the embodiments may be implemented in appropriate combination, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0048] 1 dye-sensitized solar cell, 11 first substrate, 12 second substrate, 13 electrode, 14 counter electrode, 15 electron transport layer, 16 light absorption layer, 17 catalyst layer, 18 electrolyte, 19 upper and lower conductive sealing material, 20 external sealing material.

Claims

1. An electrode; a light absorbing layer formed on the electrode and including an electron collector and a dye; a counter electrode disposed opposite the electrode; The present invention comprises a plurality of units including a vertical conductive sealing material is formed between adjacent first and second units among the plurality of units to electrically connect the first and second units; The vertical conductive sealing material has a conductive portion where the electrode extended from the first unit and the counter electrode extended from the second unit face each other, and a non-conductive portion where the electrode extended from the first unit and the counter electrode extended from the second unit do not face each other. Solar cell.

2. The electrode is formed on a first substrate; the counter electrode is formed on a second substrate facing the first substrate, the non-conductive portion is a portion in the vertical conductive sealing material where the first substrate and the second substrate face each other, a portion in the vertical conductive sealing material where the electrode and the second substrate face each other, or a portion in the vertical conductive sealing material where the counter electrode and the first substrate face each other. The solar cell according to claim 1 .

3. a non-conductive portion in which the electrode and the second substrate face each other or a non-conductive portion in which the counter electrode and the first substrate face each other is disposed between the plurality of conductive portions; The solar cell according to claim 2 .

4. The widths of the conductive portion and the non-conductive portion along the longitudinal direction of the upper and lower conductive sealing material are equal. The solar cell according to claim 1 .

5. The widths of the conductive portion and the non-conductive portion along the longitudinal direction of the vertical conductive sealing material are different. The solar cell according to claim 1 .

6. The electrode and the counter electrode each have a comb shape extending toward the conductive portion. The solar cell according to claim 1 .

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