Dye-sensitized solar cell

Abstract

To provide a dye-sensitized solar cell having further improved power generation performance.SOLUTION: A dye-sensitized solar cell includes a plurality of units including an electrode, an electron transport layer, a light absorbing layer, a counter electrode, a catalyst layer, an electrolyte, and a sealant. The electrode is formed on a first substrate. The electron transport layer is formed on the electrode. The light absorbing layer is formed on the electron transport layer, and includes an electron collector and a dye. The counter electrode is formed on a second substrate that is disposed to face the first substrate. The catalyst layer is formed on the counter electrode. The electrolyte fills a portion between the light absorbing layer and the catalyst layer. The sealant seals the electrode, the electron transport layer, the light absorbing layer, the counter electrode, the catalyst layer, and the electrolyte. The size in a current-flow direction of the unit of a power generating element constituting a region surrounded by the inner wall of the sealant of each unit is 10 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] With the advancement of IoT (Internet of Things) technology, the use of autonomous sensors as electronic devices in edge devices is expected to expand. An autonomous sensor is equipped with a secondary battery such as a lithium-ion battery, and while sensing using the power of this secondary battery, it also autonomously charges the secondary battery. Solar cells are used as a means of charging the secondary battery without a power supply. Solar cells are broadly classified into silicon solar cells, compound solar cells, and organic solar cells. Among the organic solar cells, dye sensitized solar cells (DSC) are well known. Dye sensitized solar cells generate electricity through an oxidation-reduction reaction using a dye for absorbing light and an electrolyte. Improvements in the power generation performance of dye sensitized solar cells are expected to enable efficient charging of secondary batteries. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 141905 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a dye-sensitized solar cell with further improved power generation performance. [Means for solving the problem]

[0005] A dye-sensitized solar cell according to one embodiment includes a plurality of units of a dye-sensitized solar cell, each unit including an electrode, an electron transport layer, a light absorbing layer, a counter electrode, a catalyst layer, an electrolyte, and a sealant. The electrode is formed on a first substrate. The electron transport layer is formed on the electrode. The light absorbing layer is formed on the electron transport layer and includes an electron collector and a dye. The counter electrode is formed on a second substrate disposed opposite the first substrate. The catalyst layer is formed on the counter electrode. The electrolyte is filled between the light absorbing layer and the catalyst layer. The sealant is interposed between the first substrate and the second substrate, and seals the electrode, the electron transport layer, the light absorbing layer, the counter electrode, the catalyst layer, and the electrolyte. The area surrounded by the inner wall of the sealant of each unit constitutes one power generating element. The size of each power generating element in the unit in the direction of current flow is 10 mm or less. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide a dye-sensitized solar cell with further improved power generation performance. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a dye-sensitized solar cell according to an embodiment. [Diagram 2] FIG. 2 is a plan view of the dye-sensitized solar cell as viewed from the first substrate side. [Diagram 3] FIG. 3 is a diagram for explaining the principle of power generation in one unit of the dye-sensitized solar cell. [Figure 4] FIG. 4 is a diagram showing the IV characteristics of an example of one unit in a dye-sensitized solar cell. [Diagram 5] FIG. 5 is a graph showing the relationship between cell area and fill factor. [Figure 6] FIG. 6 is a graph showing the relationship between the cell size in the current direction and the fill factor. [Figure 7] FIG. 7 is a graph showing the relationship between the vertical size ratio and the fill factor. [Figure 8]FIG. 8 is a diagram showing the configuration of a dye-sensitized solar cell formed by arranging in parallel a dye-sensitized solar cell module including five cells connected in series and another dye-sensitized solar cell module including five cells connected in series. [Figure 9] FIG. 9 is a diagram showing a modified example of the series connection. [Figure 10] FIG. 10 is a diagram showing a configuration of a counter electrode formed on a second substrate in the second modification. [Figure 11A] FIG. 11A is a diagram showing an example of a cell that can be formed in Modification 2. As shown in FIG. [Figure 11B] FIG. 11B is a diagram showing an example of a cell that can be formed in the second modification. [Figure 11C] FIG. 11C is a diagram showing an example of a cell that can be formed in Modification 2. As shown in FIG. [Figure 11D] FIG. 11D is a diagram showing an example of a cell that can be formed in Modification 2. [Figure 11E] FIG. 11E is a diagram showing an example of a cell that can be formed in Modification 2. As shown in FIG. [Figure 11F] FIG. 11F is a diagram showing an example of a cell that can be formed in Modification 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing an example of the configuration of a dye-sensitized solar cell according to an embodiment. A dye-sensitized solar cell 1 according to an embodiment is a dye-sensitized solar cell module with a Z-type structure, which is configured by connecting a plurality of dye-sensitized solar cell units U1, U2, U3, and U4 in series. In Fig. 1, the number of units is four. The number of units is not limited to four.

[0009] 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.

[0010] 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 (TCO) film 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 in 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 electrode 13 faces a counter electrode 14 without an electron transport layer 15, a light absorption layer 16, or a catalyst layer 17, which will be described later. 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. Wiring is drawn out from the terminal 131. This wiring is connected to one end of a load not shown.

[0011] 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 wire is drawn out from the terminal 141. This wire is connected to the other end of a load (not shown).

[0012] 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.

[0013] 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, an aggregate of minute oxide semiconductors, for example, titanium oxide (TiO2). The dye is, for example, a ruthenium (Ru) dye (RU) (N719 dye, etc.). The electron collector is not limited to titanium oxide, but may be, for example, zinc oxide, tin oxide, tungsten oxide, niobium oxide, indium oxide, and a complex thereof. In addition, 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, etc. may be used as pure organic dyes.

[0014] 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.

[0015] An electrolyte 18 is filled between the light absorption layer 16 and the catalyst layer 17 of each unit. As a solvent for the electrolyte 18, for example, acetonitrile, methoxyacetonitrile, ethylene carbonate, etc. can be used. As a solute for the electrolyte 18, for example, iodine (I2), 1,2-dimethyl-3-n-propylimidazolium iodide (DMPImI), lithium iodide (LiI), 4-tert-butylpyridine (TBP), etc. can be used. As shown in FIG. 1, the electrolyte 18 is partitioned by upper and lower conductive sealants 19 provided at the boundary positions between the units U1 and U2, between the units U2 and U3, and between the units U3 and U4. The upper and lower conductive sealants 19 are formed by incorporating a conductive agent containing metal particles into a resin having excellent solvent resistance, such as an acrylic resin or an olefin resin. The vertical conductive sealant 19 bonds the first substrate 11 and the second substrate 12 and is provided between the opposing electrodes to provide electrical continuity between the units. That is, the vertical conductive sealant 19 provided at the boundary between the unit U1 and the unit U2 provides electrical continuity between the electrode 13 of the unit U1 and the counter electrode 14 of the unit U2. The vertical conductive sealant 19 provided at the boundary between the unit U2 and the unit 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 unit U3 and the unit 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.

[0016] Furthermore, 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 solution 18 from leaking out to the outside. That is, the electrolyte solution 18 is sealed by the first substrate 11, the second substrate 12, the upper and lower conductive sealing material 19, and the external sealing material 20. The external sealing material 20 is, for example, a resin.

[0017] FIG. 2 is a plan view of the dye-sensitized solar cell 1 seen from the first substrate 11 side. In the embodiment, the area surrounded by the inner wall of the vertical conductive sealant 19 and the external sealant 20 of each unit constitutes a cell in each unit. The cell is a power generating element that contributes to power generation in each unit. In FIG. 2, one cell is shown as EL. In the following description, the size along the direction of the current flowing in each unit is A, and the size along the direction perpendicular to the current direction is B. For example, in the case of the dye-sensitized solar cell 1 having the configuration shown in FIG. 1, the current flows along the arrangement direction of the units. Therefore, in the case of the configuration of FIG. 1, the direction of the current flow is the short side direction of the cell. In this case, as shown in FIG. 2, the size of the cell in the short side direction is A, and the size of the cell in the long side direction is B. The cell area is the product of A and B. Hereinafter, the description will be continued assuming that the direction parallel to the short side direction of the cell is the horizontal direction, and the direction parallel to the long side direction of the cell is the vertical direction.

[0018] 3 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 (TiO2), the dye is a ruthenium (Ru) dye, and the electrolyte 18 is an iodine (I) electrolyte.

[0019] 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)

[0020] Electrons emitted from the excited dye 16a (e - The electrons injected into the electron collector 16b move to the electrode 13, which is an anode electrode.

[0021] 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 ion (I3 - The reaction formula is shown in the following formulas (2) and (3). Ru+e - →Ru (2) 3I - →I3 - +2e - (3)

[0022] The triiodide ion (I3 - ) is transported from the cathode electrode 14 to the counter electrode 14 by electrons (e - ) is received by the counter electrode 14. 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 (I3 - ) is absorbed by the iodide ion (I3 - ) is the iodide ion (I - ) The reaction formula is shown, for example, in the following formula (4). I3 - +2e - →3I - (4)

[0023] 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.

[0024] Fig. 4 is a diagram showing the IV characteristics of an example of one unit in a dye-sensitized solar cell, showing the characteristics under illumination of 1 sun (illuminance equivalent to direct sunlight in midsummer, approximately 100,000 lux) and the characteristics under illumination of 200 lux.

[0025] The fill factor is known as a parameter that can be calculated from the IV characteristics. The fill factor is calculated from Pmax / (Voc x Isc), where Pmax is the maximum output, Isc is the short-circuit current, and Voc is the open-circuit voltage obtained from the IV characteristics. The maximum output Pmax is the output at the point on the IV characteristic curve where the product of the current and voltage is maximum. The short-circuit current Isc is the current when the voltage is zero on the IV characteristic curve. The open-circuit voltage Voc is the voltage when the current is zero on the IV characteristic curve.

[0026] Usually, under the same conditions of short circuit current Isc and open circuit voltage Voc, the higher the fill factor of the dye-sensitized solar cell, the higher the maximum output that can be obtained. The fill factor of the current dye-sensitized solar cell is at most 0.8. In general, the fill factor tends to be high under low illuminance and low under high illuminance. One of the reasons for the decrease in the fill factor under high illuminance is that electron recombination in the light absorption layer is more likely to occur under high illuminance than under low illuminance. Thus, the fill factor also changes depending on the illuminance of the light incident on the dye-sensitized solar cell, so it is important that the dye-sensitized solar cell can maintain a sufficient fill factor even if the illuminance changes.

[0027] Fig. 5 is a graph showing the relationship between cell area and fill factor. The graph in Fig. 5 shows the fill factor calculated from the IV characteristics measured in the same manner as in Fig. 4 while changing only the cell area under illumination of 1 sun. Here, the fill factor in Fig. 5 is calculated from the IV characteristics measured in the same manner as in Fig. 4 while changing only the cell area under illumination of 1 sun. 2 It is expressed as a ratio when the fill factor is 1 when

[0028] As shown in Fig. 5, under the same illumination, the fill factor tends to decrease as the cell area increases. For example, when the cell area is 1 cm 2 The fill factor drops by about 20%. Therefore, in order to maintain a high fill factor even under high illuminance, it is desirable to have a small cell area.

[0029] Figure 6 is a graph showing the relationship between cell size in the direction of current flow and the fill factor. As mentioned above, the current flow direction is horizontal in the configuration of Figure 1. The graph in Figure 6 shows the relationship between the cell size in the direction of current flow and the fill factor when the cell area is 1 cm under illumination of 1 sun. 2 6 is a graph of the fill factor calculated based on the IV characteristics measured while fixing the cell size A in the horizontal direction and varying only the cell size A in the horizontal direction. Here, the fill factor in Fig. 6 is expressed as a ratio when the fill factor when the cell size A is 2.5 mm is taken as 1.

[0030] As shown in Figure 6, for the same cell area, the fill factor tends to decrease as the cell size A in the horizontal direction (current direction) increases. When the cell area exceeds 10 mm, the decrease in the fill factor increases rapidly. Therefore, in order to maintain a high fill factor under conditions of a constant cell area, it is desirable for the cell size A in the horizontal direction to be 10 mm or less.

[0031] FIG. 7 is a graph showing the relationship between the aspect ratio and the fill factor. Here, the aspect ratio B2 / B1 is the ratio between the aspect ratio B1 / A1 when the horizontal cell size A is A1 and the vertical cell size B is B1, and the aspect ratio B2 / A1 when the horizontal cell size A is also A1 and the vertical cell size is B2. In other words, a large aspect ratio B2 / B1 means that the vertical cell size is longer than the horizontal cell size. Here, the fill factor in FIG. 7 is expressed as a ratio when the fill factor when the vertical size ratio is 1 is 1.

[0032] As shown in Fig. 7, for the same horizontal cell size, the fill factor tends to decrease as the vertical size ratio, i.e., the vertical cell size B, increases. However, the decrease in the fill factor due to an increase in the vertical cell size tends to be smaller than the decrease in the fill factor due to an increase in the horizontal cell size.

[0033] As mentioned above, it is desirable for the cell area of ​​each cell to be small in order to maintain the fill factor. On the other hand, a certain amount of light-receiving area is necessary to obtain the necessary output for the dye-sensitized solar cell 1, so it is desirable for the cell area of ​​each cell to be large in order to expand the light-receiving area. To achieve both of these, it is desirable to reduce the cell area by reducing the horizontal cell size A while keeping the vertical cell size B as small as possible.

[0034] From the above, in the embodiment, the sizes of the electrode 13, the counter electrode 14, the electron transport layer 15, the light absorbing layer 16, and the catalyst layer 17, and the arrangement of the upper and lower conductive sealing materials 19 and the external sealing material 20 surrounding these are determined so that the cell size A in the current direction is 10 mm or less.

[0035] As described above, according to the embodiment, the cell size in the current direction of one cell in the dye-sensitized solar cell is set to 10 mm or less, thereby suppressing a decrease in the fill factor under high illuminance.

[0036] (Variation 1) Modifications of the embodiment will be described below. In the above-mentioned embodiment, the current direction of one cell is set to 10 mm or less, and the cell area is reduced, thereby suppressing the reduction of the fill factor even under high illuminance. On the other hand, a certain amount of light receiving area is required to obtain the necessary output as a dye-sensitized solar cell. As a configuration for obtaining a light receiving area without changing the cell area, it is considered to arrange many cells two-dimensionally.

[0037] 8 is a diagram showing the configuration of a dye-sensitized solar cell 1 configured by arranging in parallel a dye-sensitized solar cell module including five cells EL connected in series via a vertical conductive sealing material 19a, and a dye-sensitized solar cell module including five cells EL connected in series via a vertical conductive sealing material 19b. Here, the cell size A in the current direction of one cell EL is 10 mm or less. Here, as described in the embodiment, the number of cells connected in series is not limited to five. Furthermore, the number of rows of the dye-sensitized solar cell modules arranged in parallel is not limited to two rows.

[0038] In FIG. 8, the rightmost cell EL of the five cells EL connected in series via the vertical conductive sealing material 19a is connected to the terminal 131a, and the leftmost cell EL is connected to the terminal 141a. Similarly, the rightmost cell EL of the five cells EL connected in series via the vertical conductive sealing material 19b is connected to the terminal 131b, and the leftmost cell EL is connected to the terminal 141b. With this configuration, the five cells EL connected in series via the vertical conductive sealing material 19a and the five cells EL connected in series via the vertical conductive sealing material 19b can each operate independently as a dye-sensitized solar cell module with a Z-type structure. This ensures the necessary output of the dye-sensitized solar cell 1.

[0039] In Fig. 8, multiple cells EL are connected by vertical conductive sealing materials arranged at the boundary positions between units, similarly to Fig. 1. In contrast, the vertical conductive sealing materials do not necessarily have to be arranged at the boundary positions between units. As shown in Fig. 9, the vertical conductive sealing materials 19a and 19b may be arranged at the position of the external sealing material 20. In this case, the sealing material arranged at the boundary positions between units does not need to contain a conductive agent containing metal particles.

[0040] According to the above-described first modification, it is possible to ensure a light-receiving area large enough to obtain the necessary output as the dye-sensitized solar cell 1 without changing the cell area.

[0041] In addition, in the dye-sensitized solar cell having the configuration described in FIG. 8 and FIG. 9, the five cells EL connected in series via the upper and lower conductive sealing materials 19a and the five cells EL connected in series via the upper and lower conductive sealing materials 19b can each operate independently as a dye-sensitized solar cell module having a Z-type structure. If even a part of the cells connected in series has a poor electrical connection, the entire dye-sensitized solar cell module including that cell will not operate. However, by paralleling the dye-sensitized solar cell modules, even if one of the dye-sensitized solar cell modules stops operating, the other dye-sensitized solar cell module can still operate. Similarly, if even a part of the cells connected in series is not exposed to light for a long period of time, that cell will eventually corrode due to an excess or deficiency of electrons, and the entire dye-sensitized solar cell module including that cell will not operate. However, by paralleling the dye-sensitized solar cell modules, even if one of the dye-sensitized solar cell modules stops operating, the other dye-sensitized solar cell module can still operate. In this way, by arranging in parallel dye-sensitized solar cell modules including cells connected in series via upper and lower conductive sealing materials, a redundancy effect can be expected.

[0042] (Variation 2) Next, Modification 2 will be described. Fig. 10 is a diagram showing the configuration of the counter electrode formed on the second substrate in Modification 2. As shown in Fig. 10, in Modification 2, the second substrate 12 is provided with two-dimensionally small counter electrodes 14a divided into small tile shapes. Although not shown in Fig. 10, the first substrate 11 is also provided with two-dimensionally small electrodes and a small electron transport layer divided into small tile shapes so as to face each of the small counter electrodes 14a. The electron transport layer does not necessarily have to be divided into tiles.

[0043] As shown in FIG. 10, in the second modification, two or more terminals, four terminals 131a, 131b, 131c, and 131d and four terminals 141a, 141b, 141c, and 141d are provided on the second substrate 12.

[0044] 11A to 11F are diagrams showing examples of cells that can be formed in Modification 2. In Modification 2, the size of the cells, the number of cells in series, and the number of cells in parallel can be freely rearranged by changing the pattern of the light absorbing layer 16 of the first substrate 11, the pattern of the catalyst layer 17 of the second substrate 12, and the pattern of the sealant provided at the boundary position of the cells.

[0045] 11A is an example in which one cell EL is formed on two micro counter electrodes 14a in the horizontal direction and eight in the vertical direction. In practice, a single catalyst layer 17 is formed for two micro counter electrodes 14a in the horizontal direction and eight in the vertical direction. Similarly, a single light absorbing layer 16 is formed for each microelectrode and microelectron transport layer of the first substrate 11 so as to face the catalyst layer 17. As a result, two micro counter electrodes 14a in the horizontal direction and eight microelectrodes in the vertical direction can function as one counter electrode 14. Similarly, two microelectrodes in the horizontal direction and eight microelectrodes in the vertical direction can function as one electrode 13 and electron transport layer 15.

[0046] In the case of the configuration of FIG. 11A, five cells EL can be formed. The five cells EL are connected in series by forming a vertical conductive sealant 19 at the boundary positions of the five cells EL. In addition, the 16 microelectrodes included in the rightmost cell EL of the five cells EL connected in series are connected to any one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131a, and the 16 micro counter electrodes 14a included in the leftmost cell EL are connected to any one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a. With this configuration, the dye-sensitized solar cell 1 can operate as a dye-sensitized solar cell module consisting of five units connected in series. In the configuration of FIG. 11A, the current I flows in order from the leftmost unit to the rightmost unit of the five units. Here, even in the configuration of FIG. 11A, it is desirable that the cell size A in the current direction of one cell EL, that is, the horizontal direction, is 10 mm or less.

[0047] FIG. 11B shows an example in which one cell EL is formed on one micro counter electrode 14a in the horizontal direction and eight in the vertical direction.

[0048] In the case of the configuration of FIG. 11B, ten cells EL can be formed. The ten cells EL are connected in series by forming the upper and lower conductive sealing material 19 at the boundary positions of the ten cells EL. Furthermore, eight microelectrodes included in the rightmost cell EL of the ten cells EL connected in series are connected to any one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131a, and eight micro counter electrodes included in the leftmost cell EL are connected to any one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a. With this configuration, the dye-sensitized solar cell 1 can operate as a dye-sensitized solar cell module consisting of ten units connected in series. In the configuration of FIG. 11B, the current I flows in order from the leftmost unit to the rightmost unit among the ten units. Here, even in the configuration of FIG. 11B, it is desirable that the cell size A in the current direction of one cell EL, i.e., the horizontal direction, is 10 mm or less. In the configuration of FIG. 11B, the cell size A in the current direction can be made smaller than that in the configuration of FIG. 11A.

[0049] FIG. 11C shows an example in which one cell EL is formed on two micro counter electrodes 14a in the horizontal direction and four in the vertical direction.

[0050] In the case of the configuration of Fig. 11C, ten cells EL can be formed. Then, at the boundary positions of five cells EL arranged in the horizontal direction among the ten cells EL, the upper and lower conductive sealing materials 19 are formed, so that the five cells EL are connected in series. In addition, among the cells EL connected in series in the first row, the eight microelectrodes included in the rightmost cell EL are connected to one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131a, and the micro counter electrode 14a included in the leftmost cell EL is connected to one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a. Similarly, the eight microelectrodes included in the rightmost cell EL among the cells EL connected in series in the second row are connected to another one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131c, and the eight micro counter electrodes 14a included in the leftmost cell EL are connected to another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141c. With this configuration, the dye-sensitized solar cell 1 can operate as two dye-sensitized solar cell modules each consisting of five units connected in series arranged in parallel. In the configuration of FIG. 11C, the current I flows in order from the leftmost unit of each dye-sensitized solar cell module. Here, in the configuration of FIG. 11C, it is desirable that the cell size A in the current direction of one cell EL, i.e., the horizontal direction, is 10 mm or less.

[0051] FIG. 11D shows an example in which one cell EL is formed on two micro counter electrodes 14a in the horizontal direction and four in the vertical direction.

[0052] In the case of the configuration of FIG. 11D, ten cells EL can be formed. Then, at the boundary positions of five cells EL arranged in the horizontal direction among the ten cells EL, a vertical conductive sealant 19 is formed, so that the five cells EL are connected in series. Then, at the boundary position between the rightmost cell EL of the cells connected in series in the first row and the rightmost cell EL of the cells connected in series in the second row, a vertical conductive sealant 19 is also formed, so that the ten cells EL are connected in series. Eight microelectrodes included in the leftmost cell EL of the cells connected in series in the first row are connected to one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a, and eight micro counter electrodes 14a included in the leftmost cell EL of the cells connected in series in the second row are connected to another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141c. With this configuration, the dye-sensitized solar cell 1 can operate as a dye-sensitized solar cell module consisting of ten units connected in series. In the configuration of Fig. 11D, the current I flows in sequence from the leftmost unit of the dye-sensitized solar cell module in the first row to the rightmost unit of the dye-sensitized solar cell module in the second row. Here, even in the configuration of Fig. 11D, it is desirable that the current direction of one cell EL, i.e., the cell size A in the lateral direction, is 10 mm or less.

[0053] FIG. 11E shows an example in which one cell EL is formed on two micro counter electrodes 14a in the horizontal direction and two in the vertical direction.

[0054] In the case of the configuration of Fig. 11E, 20 cells EL can be formed. Then, at the boundary positions of five cells EL arranged in the horizontal direction among the 20 cells EL, the upper and lower conductive sealing materials 19 are formed, so that the five cells EL are connected in series. In addition, among the cells EL connected in series in the first row, the four microelectrodes included in the rightmost cell EL are connected to one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131a, and the micro counter electrode 14a included in the leftmost cell EL is connected to one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a. Similarly, the four microelectrodes included in the rightmost cell EL of the cells EL connected in series in the second row are connected to another one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131b, and the four micro counter electrodes 14a included in the leftmost cell EL are connected to another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141b. Similarly, the four microelectrodes included in the rightmost cell EL of the cells EL connected in series in the third row are connected to yet another one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131c, and the four micro counter electrodes 14a included in the leftmost cell EL are connected to yet another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141c. Similarly, the four microelectrodes included in the rightmost cell EL among the cells EL connected in series in the fourth row are connected to yet another one of the four terminals 131a, 131b, 131c, and 131d, for example, the terminal 131d, and the four micro counter electrodes 14a included in the leftmost cell EL are connected to yet another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141d. With this configuration, the dye-sensitized solar cell 1 can operate as four dye-sensitized solar cell modules each consisting of five units connected in series arranged in parallel. In the configuration of FIG. 11E, the current I flows in order from the leftmost unit of each dye-sensitized solar cell module. Here, in the configuration of FIG. 11E, it is desirable that the cell size A in the current direction of one cell EL, i.e., the horizontal direction, is 10 mm or less.

[0055] FIG. 11F shows an example in which one cell EL is formed on two micro counter electrodes 14a in the horizontal direction and two in the vertical direction.

[0056] In the case of the configuration of FIG. 11F, 20 cells EL can be formed. Then, at the boundary positions of five cells EL arranged in the horizontal direction among the ten cells EL, a vertical conductive sealing material 19 is formed, so that the five cells EL are connected in series. Then, at the boundary position between the rightmost cell EL of the cells connected in series in the first row and the rightmost cell EL of the cells connected in series in the second row, a vertical conductive sealing material 19 is also formed, so that the ten cells EL are connected in series. Similarly, at the boundary position between the rightmost cell EL of the cells connected in series in the third row and the rightmost cell EL of the cells connected in series in the fourth row, a vertical conductive sealing material 19 is also formed, so that the ten cells EL are connected in series. In addition, the four microelectrodes included in the leftmost cell EL of the cells connected in series in the first row are connected to one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141a, and the four micro counter electrodes 14a included in the leftmost cell EL of the cells connected in series in the second row are connected to another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141b. Similarly, the four microelectrodes included in the leftmost cell EL of the cells connected in series in the third row are connected to one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141c, and the four micro counter electrodes 14a included in the leftmost cell EL of the cells connected in series in the fourth row are connected to another one of the four terminals 141a, 141b, 141c, and 141d, for example, the terminal 141d. With this configuration, the dye-sensitized solar cell 1 can operate as two dye-sensitized solar cell modules arranged in parallel, each of which is made up of 10 units connected in series. In the configuration of FIG. 11F, the current I flows in sequence from the leftmost unit of the dye-sensitized solar cell module in the first row to the leftmost unit of the dye-sensitized solar cell module in the second row, and also flows in sequence from the leftmost unit of the dye-sensitized solar cell module in the third row to the leftmost unit of the dye-sensitized solar cell module in the fourth row. Here, even in the configuration of FIG. 11F, it is desirable that the cell size A in the current direction of one cell EL, i.e., the horizontal direction, is 10 mm or less.

[0057] In the above-described modified example 2, it is possible to freely change the output characteristics of the dye-sensitized solar cell 1 with respect to the design of the common electrode.

[0058] 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]

[0059] 1 electronic device, 10 solar cell, 11 first substrate, 12 second substrate, 13 electrode, 14 counter electrode, 14a micro-counter electrode, 15 electron transport layer, 16 light absorption layer, 17 catalyst layer, 18 electrolyte, 19, 19a, 19b upper and lower conductive sealing material, 20 external sealing material.

Claims

1. An electrode formed on a first substrate; an electron transport layer formed on the electrode; a light absorbing layer formed on the electron transport layer and including an electron collector and a dye; a counter electrode formed on a second substrate disposed opposite the first substrate; A catalyst layer formed on the counter electrode; an electrolyte filled between the light absorbing layer and the catalyst layer; a sealant interposed between the first substrate and the second substrate, for sealing the electrode, the electron transport layer, the light absorbing layer, the counter electrode, the catalyst layer, and the electrolyte; A dye-sensitized solar cell comprising a plurality of units, an area surrounded by an inner wall of the sealing material of each of the units constitutes one power generating element, The size of each of the power generating elements in the direction of current flow through the unit is 10 mm or less. Dye-sensitized solar cells.

2. the plurality of units are connected in series via a vertical conductive sealing material formed in a part of the sealing material to constitute a dye-sensitized solar cell module; A plurality of the power generating elements are arranged in parallel. The dye-sensitized solar cell according to claim 1 .

3. The electrode is divided into a plurality of tiled microelectrodes; The counter electrode is divided into a plurality of tile-shaped micro-counter electrodes. The dye-sensitized solar cell according to claim 1 .

4. A single light absorbing layer is formed on a plurality of the microelectrodes; A single catalyst layer is formed on a plurality of the micro counter electrodes. The dye-sensitized solar cell according to claim 3 .

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