Dye-sensitized solar cells

Abstract

To provide a dye-sensitized solar cell which can be easily manufactured while performing conductive connection of electrodes between units by a sealing material with conductivity.SOLUTION: A dye-sensitized solar cell comprises: a first unit; and a second unit. The first unit includes: a first electrode formed onto a first substrate; a first opposite electrode that is formed on a second substrate oppositely arranged to the first substrate; a first light absorption layer that is formed between the first electrode and the first opposite electrode, and contains an electron capture agent and a coloring agent; a first electrolyte; and a first catalyst layer. The second unit includes: a second electrode formed onto the first substrate; a second opposite electrode formed onto the second substrate; a second light absorption layer that is formed between the second electrode and the second opposite electrode, and contains the electron capture agent and the coloring agent; a second electrolyte; and a second catalyst layer. The first electrode and the second opposite electrode are conducted and connected by a conductive part formed in a sealing material containing an ultraviolet cure resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Solar cells are expected to be used as power sources and energy harvesting elements for IoT (Internet of Things) devices. Solar cells are broadly classified into silicon-based solar cells, compound-based solar cells, and organic-based solar cells. Among organic-based solar cells, dye-sensitized solar cells (DSCs) are well known. Dye-sensitized solar cells generate electricity through a redox reaction using a dye to absorb light and an electrolyte. The electrolytes used in dye-sensitized solar cells include solid-type electrolytes and liquid-type electrolytes.

[0003] Dye-sensitized solar cells can be used as modules in which multiple units of dye-sensitized solar cells are connected in series. To connect multiple units in series, the electrodes provided on each unit may be electrically connected using a conductive encapsulant. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2005-093252 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present disclosure aims to provide a dye-sensitized solar cell that is easy to manufacture, while electrically connecting electrodes between units using a conductive sealing material. [Means for solving the problem]

[0006] One embodiment of a dye-sensitized solar cell comprises a first unit and a second unit. The first unit includes a first electrode formed on a first substrate, a first counter electrode formed on a second substrate positioned opposite the first substrate, a first light-absorbing layer formed between the first electrode and the first counter electrode containing an electron-collecting agent and a dye, a first electrolyte, and a first catalyst layer. The second unit includes a second electrode formed on the first substrate, a second counter electrode formed on the second substrate, a second light-absorbing layer formed between the second electrode and the second counter electrode containing an electron-collecting agent and a dye, a second electrolyte, and a second catalyst layer. The first electrode and the second counter electrode are electrically connected by a conductive portion formed in a encapsulant containing an ultraviolet-curing resin. The sealing material is provided between the first substrate and the second substrate so as to surround the first unit and the second unit, sealing the first unit and the second unit together with the first substrate and the second substrate. The conductive portion is formed by conductive particles mixed into at least a portion of the sealing material. . [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a dye-sensitized solar cell that is easy to manufacture, while electrically connecting the electrodes between units with a conductive sealing material. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows an example of the configuration of a dye-sensitized solar cell according to one embodiment. [Figure 2] Figure 2 is a top view showing the connection structure between the electrode and the counter electrode in the embodiment. [Figure 3] Figure 3 is a diagram illustrating the power generation principle in a single unit. [Figure 4] Figure 4 is a top view showing the connection structure between the electrode and the counter electrode in a modified example. [Figure 5] Figure 5 is a top view showing the connection structure between the electrode and the counter electrode in a modified example. [Figure 6] Figure 6 is a top view showing the connection structure between the electrode and the counter electrode in a modified example. [Figure 7] Figure 7 is a top view showing the connection structure between the electrode and the counter electrode in a modified example. [Figure 8]FIG. 8 is a top view showing a connection structure between an electrode and a counter electrode in a modified example. [Figure 9] FIG. 9 is a top view showing a connection structure between an electrode and a counter electrode in a modified example. [Figure 10] FIG. 10 is a top view showing a connection structure between an electrode and a counter electrode in a modified example. [Figure 11A] FIG. 11A is a top view showing a connection structure between an electrode and a counter electrode in a modified example. [Figure 11B] FIG. 11B is a cross-sectional view showing the structure of region A in FIG. 11A. <舍 [Figure 11C] FIG. 11C is a cross-sectional view showing the structure of region B in FIG. 11A. [Figure 12A] FIG. 12A is a diagram showing an example of the configuration of a dye-sensitized solar cell in a modified example. [Figure 12B] FIG. 12B is a diagram showing an example of the configuration of a dye-sensitized solar cell in a modified example. [

MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, embodiments 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. The dye-sensitized solar cell 1 according to the embodiment is a dye-sensitized solar cell module in which a plurality of units U1, U2, U3, U4 of dye-sensitized solar cells 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 unit U1, U2, U3, U4 of the dye-sensitized solar cell 1 is formed side by side in a one-dimensional direction 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 arranged to face the first substrate 11. The second substrate 12 is a transparent substrate such as a glass substrate, similar to the first substrate 11.

[0011] It should be noted that there seems to be a misspelling in the original text where "<舍 [Figure 11C] " is likely an incorrect tag. It is presented as is in the translation for the purpose of maintaining the original content.Electrodes 13 are formed at the location of each unit on the first substrate 11. The spacing between the electrodes 13 is such that there is no influence from, for example, leakage current between adjacent electrodes. The electrodes 13 are formed from a transparent conductive oxide film (TCO) such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO). Each electrode 13 is used as the anode electrode of the corresponding unit. In addition, the electrode 13 formed on one of the end units U1 and U4 in the dye-sensitized solar cell 1, unit U1 in Figure 1, is led out to the outside of the dye-sensitized solar cell 1. A terminal 131 is formed on the led-out electrode 13. Wiring is led out from terminal 131. This wiring is connected to one end of a load (not shown).

[0012] Counter electrodes 14 are formed at the location of each unit on the second substrate 12. The spacing between the counter electrodes 14 is such that there is no influence from, for example, leakage current between adjacent electrodes. The counter electrodes 14 are formed from a transparent conductive oxide film (TCO) such as indium tin oxide (ITO) or fluorine-doped tin oxide (FTO), similar to the electrodes 13. Each counter electrode 14 is used as the cathode electrode of the corresponding unit. In addition, the counter electrode 14 formed on the other unit of the end units U1 and U4 in the dye-sensitized solar cell 1, unit U4 in Figure 1, is led out to the outside of the dye-sensitized solar cell 1. A terminal 141 is formed on the led-out counter electrode 14. Wiring is led out from terminal 141. This wiring is connected to the other end of a load (not shown).

[0013] 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 xIt is composed of a metal oxide film. The electron transport layer 15 may be provided to suppress losses caused by the electrode 13, which is composed of TCO, which has higher resistance than metal. Furthermore, the formation of the electron transport layer 15 improves the adhesion of the light absorption layer 16 that is further formed on top of the electron transport layer 15. It is desirable that the electron transport layer 15 be formed thinner than the electrode 13, for example, a thin layer of 10 nm or less.

[0014] A light-absorbing layer 16 is formed on each electron transport layer 15. The light-absorbing layer 16 is a layer formed by adsorbing a dye onto an electron-catching agent. The electron-catching agent is, for example, a fine oxide semiconductor, such as an aggregate of titanium dioxide (TiO2). The dye is, for example, a ruthenium (Ru) dye (RU) (such as N719 dye). The electron-catching agent is not limited to titanium dioxide, but may also be, for example, zinc oxide, tin oxide, tungsten oxide, niobium oxide, indium oxide, or composites thereof. Furthermore, the dye is not limited to N719 dye. For example, as a ruthenium-based dye, N3 dye, BlackDye, etc., or as a pure organic dye, D149, xanthene, PVK, merocyanine, oxazine, etc. may be used.

[0015] A catalyst layer 17 is formed on the counter electrode 14 that constitutes the cathode electrode of each unit. The catalyst layer 17 is, for example, a platinum layer. It is desirable that the catalyst layer 17 be formed thinner than the counter electrode 14, for example, a thin layer of 10 nm or less.

[0016] An electrolyte 18 is filled between the light-absorbing layer 16 and the catalyst layer 17 of each unit. As the solvent for the electrolyte 18, for example, acetonitrile, methoxyacetonitrile, ethylene carbonate, etc., can be used. As the 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.

[0017] Furthermore, a encapsulating material 19 is provided on the outermost periphery of the dye-sensitized solar cell 1 so as to surround units U1, U2, U3, and U4. In addition, the encapsulating material 19 is also provided at the boundary positions between units U1 and U2, between units U2 and U3, and between units U3 and U4. The encapsulating material 19 is made of an ultraviolet-curing resin such as acrylic resin. The encapsulating material 19 bonds the first substrate 11 and the second substrate 12 together and prevents the electrolyte 18 from leaking out. In other words, the electrolyte 18 is sealed by the first substrate 11, the second substrate 12, and the encapsulating material 19.

[0018] Figure 2 is a top view showing the connection structure between electrode 13 and counter electrode 14 in the embodiment. Figure 2 is a top view taken from above, after cutting the dye-sensitized solar cell 1 along line II-II in Figure 1. As shown in Figure 2, electrode 13 and counter electrode 14 are substantially rectangular flat plate electrodes with a long side extending from the front to the back when the orientation of the dye-sensitized solar cell visible in Figure 1 is considered the front.

[0019] Here, at least a portion of the short side of the electrodes 13 of units U4, U3, and U2 that are not connected to terminal 131 is extended to the lower end of the conductive portion 19a formed in the sealing material 19 located at the rear of each unit. In this example, the right end portion of the short side of the electrodes 13 of units U4, U3, and U2 is extended in the longitudinal direction, which is parallel to the long side, and contacts the lower end of the conductive portion 19a formed in the sealing material 19 located at the rear of each unit.

[0020] Furthermore, at least a portion of the short side of the opposing electrode 14 of units U3, U2, and U1 that are not connected to terminal 141 is extended to the upper end of the conductive portion 19a formed in the sealing material 19 located at the rear of the unit to the left. In this example, the right end portion of the short side of the opposing electrode 14 of units U3, U2, and U1 is extended longitudinally. In addition, this right end portion is bent to the left at the location of the sealing material 19 and abuts against the upper end of the conductive portion 19a formed in the sealing material 19 located at the rear of the unit U4, U3, and U2 to the left of each unit.

[0021] In this embodiment, the conductive portion 19a is formed in the sealing material 19 using a seal-in-cloth method. Specifically, the conductive portion 19a is formed by mixing conductive particles into the connection point between the electrode 13 and the counter electrode 14 in the sealing material 19, which is made of an ultraviolet-curing resin such as acrylic resin. The conductive particles may be metal particles.

[0022] Then, the electrode 13 drawn from unit U4 and the counter electrode 14 drawn from unit U3 are electrically connected via the conductive portion 19a. Similarly, the electrode 13 drawn from unit U3 and the counter electrode 14 drawn from unit U2 are electrically connected via the conductive portion 19a of the sealing material 19. Also similarly, the electrode 13 drawn from unit U2 and the counter electrode 14 drawn from unit U1 are electrically connected via the conductive portion. In this way, units U4, U3, U2, and U1 can be connected in series.

[0023] In Figure 2, a portion of the rear-side short edge of the electrode 13 of units U4, U3, and U2 is extended to the lower end of the conductive portion 19a formed in the sealing material 19 at the rear position of each unit, and a portion of the rear-side short edge of the opposing electrode 14 of units U3, U2, and U1 is extended to the upper end of the conductive portion 19a formed in the sealing material 19 at the rear position. Alternatively, a portion of the front-side short edge of the electrode 13 of units U4, U3, and U2 may be extended to the lower end of the conductive portion 19a formed in the sealing material 19 at the front position of each unit, and a portion of the front-side short edge of the opposing electrode 14 of units U3, U2, and U1 may be extended to the upper end of the conductive portion 19a formed in the sealing material 19 located on the front side of each unit.

[0024] In addition, the conductive particles mixed into the conduction part 19a may have a role in forming the cell gap between the first substrate 11 and the second substrate 12. In this case, the particle size of the conductive particles may have a value such as 0 μm to +5 μm of the target cell gap value. The reason why the particle size of the conductive particles is equal to or greater than the value of the cell gap is that the pressing force during the bonding of the first substrate 11 and the second substrate 12 is taken into consideration.

[0025] FIG. 3 is a diagram for explaining the power generation principle in one unit. Here, FIG. 3 shows, for example, the unit U4. However, the units U1, U2, and U3 also generate power according to the same power generation principle. In addition, in the following example, the electron collector is titanium oxide (TiO2), the dye is ruthenium (Ru) dye, and the electrolytic solution 18 is iodine (I) electrolytic solution.

[0026] First, when light is incident on the dye-sensitized solar cell 1, 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 shown, for example, by the following formula (1). Ru→Ru + +e - (1)

[0027] The electrons (e - ) emitted from the excited dye 16a are injected into the electron collector 16b composed of, for example, porous titanium oxide (TiO2). The electrons injected into the electron collector 16b move to the electrode 13 which is the anode electrode of the unit U4.

[0028] On the other hand, the dye 16a that has lost electrons (e - ) is supplied with electrons from, for example, iodide ions (I - ) in the electrolytic solution 18. The iodide ions (I - ) in the electrolytic solution 18 become triiodide ions (I3 - ) when they supply electrons (e - ) to the dye 16b. The reaction formulas are shown, for example, by the following formulas (2) and (3). Ru+e - →Ru (2) 3I - →I3 - +2e - (3)

[0029] The triiodide ions (I3) produced by this oxidation reaction - ) is electrons (e - At this time, a potential difference is generated between the counter electrode 14 and electrode 13. If a load is connected between the counter electrode 14 and electrode 13, electrons that have moved to electrode 13 will move through the load to the counter electrode 14. Then, the electrons that reach the counter electrode 14 will form triiodide ions (I3). - It is absorbed by ). Through this reduction reaction, triiodide ions (I3) are produced. - ) is an iodide ion (I - Return to (). The reaction equation is shown, for example, in equation (4) below. I3 - +2e - →3I - (4) The dye-sensitized solar cell 1 generates electricity through the repeated oxidation-reduction reactions described above. For such oxidation-reduction reactions to occur, the energy level of the excited dye 16a must be higher than the energy level of the electron-collecting agent 16b, and the energy level of the ground-state dye 16a must be lower than the energy level of the electrolyte 18.

[0030] In the dye-sensitized solar cell 1 shown in Figure 1, multiple units are connected in series. In this case, when light is incident on unit U4, electrons are emitted from the dye according to the principle explained with reference to Figure 3. The electrons emitted from the dye are transferred to an electron collecting agent and then move to the anode electrode. Here, electrode 13, which is the anode electrode of unit U4, is connected to the counter electrode 14, which is the cathode electrode of unit U3, via a conductive portion 19a. Therefore, the electrons that have moved to the anode electrode of unit U4 move to the cathode electrode of unit U3. These electrons that have moved to the cathode electrode of unit U3 are used in the reduction reaction in unit U3.

[0031] Similarly, electrons released from the dye during the oxidation reaction in unit U3 move from the anode electrode of unit U3 to the cathode electrode of unit U2. These electrons then move to the cathode electrode of unit U2 and are used in the reduction reaction in unit U2. Similarly, electrons released from the dye during the oxidation reaction in unit U2 move from the anode electrode of unit U2 to the cathode electrode of unit U1. These electrons then move to the cathode electrode of unit U1 and are used in the reduction reaction in unit U1.

[0032] Furthermore, electrons released from the dye during the oxidation reaction in unit U1 move to the anode electrode of unit U1. The anode electrode of unit U1 is connected to a load. Therefore, the electrons that have moved to the anode electrode of unit U1 move to the cathode electrode of unit U4 via the load. The electrons that have moved to the cathode electrode of unit U4 are then used in the reduction reaction in unit U4.

[0033] The dye-sensitized solar cell 1 generates electricity through repeated oxidation-reduction reactions in each of the units described above. The dye-sensitized solar cell 1 has a higher power generation efficiency than the single unit shown in Figure 3.

[0034] As described above, according to the embodiment, in a dye-sensitized solar cell composed of multiple units of dye-sensitized solar cells, a portion of the short side of the anode electrode and cathode electrode of each unit is extended to the encapsulant, and the extended anode electrode and cathode electrode are electrically connected via a conductive portion formed in the encapsulant using a seal-in-cross method. In other words, according to the embodiment, the conductive portion for the conductive connection of the multiple solar cell units is not formed on the outside of the encapsulant. Therefore, a compact dye-sensitized solar cell can be provided. Furthermore, the formation of the conductive portion is carried out by mixing conductive particles during the formation of the encapsulant. Therefore, the conductive portion can be formed in the same process as the formation of the encapsulant.

[0035] Furthermore, in this embodiment, an ultraviolet-curing resin such as acrylic resin is used as the encapsulating material. Therefore, heating is unnecessary during the manufacturing of the dye-sensitized solar cell. Consequently, heat-sensitive materials can be used for each element of the dye-sensitized solar cell. This broadens the range of material choices. As a result, an easy-to-manufacture dye-sensitized solar cell is provided.

[0036] [Differentiation] The following describes some variations. In Figure 2, one electrode 13 and one opposing electrode 14 are drawn out from only one short side. In contrast, as shown in Figure 4, one electrode 13 and one opposing electrode 14 may be drawn out from both short sides. By connecting two points on one electrode to the conductive portion 19a, an improvement in power generation efficiency due to a reduction in series resistance can be expected. Furthermore, even if one of the electrodes on the back and front sides connected to the conductive portion 19a breaks, power generation can still occur as long as the other is connected. Thus, by drawing out from both short sides of the electrode, a redundant design effect can also be expected. Note that the number of drawouts from the electrode does not have to be two. For example, one electrode may be drawn out from three or more points, and the drawn-out electrodes may be electrically connected by three or more conductive portions 19a formed in the sealing material 19.

[0037] Furthermore, the electrodes do not necessarily have to be drawn out from the shorter side. For example, as shown in Figure 5, the longer right side of the electrode 13 of the right-hand unit in the adjacent unit may be drawn out to the right, and the longer left side of the opposing electrode 14 of the left-hand unit may be drawn out to the left, and these drawn-out electrodes may be connected to a conductive portion 19a formed in the sealing material 19 provided at the boundary position of the adjacent unit. In the configuration of Figure 5, the contact area between the electrode and the conductive portion is larger than in the configuration of Figure 2, so an improvement in power generation efficiency due to a reduction in series resistance can be expected.

[0038] Figure 6 shows an example of electrode extraction in a multi-stage dye-sensitized solar cell in which a first dye-sensitized solar cell module M1, consisting of four units U11, U12, U13, and U14, and a second dye-sensitized solar cell module M2, consisting of four units U21, U22, U23, and U24, are arranged in a direction perpendicular to the arrangement direction of the units. In a multi-stage dye-sensitized solar cell, sealing material 19 can be provided not only at the boundary positions of each unit of the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2, but also at the boundary position between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. In this case, as shown in Figure 6, electrode extraction from the short sides of the electrode 13 and the opposing electrode 14 can be directed towards sealing material 19 located on the inside, rather than towards sealing material 19 located on the outer periphery of the dye-sensitized solar cell.

[0039] In the first dye-sensitized solar cell module M1 shown in Figure 6, the short side of the front electrode 13 of unit U14 is extended forward, and the short side of the front counter electrode 14 of unit U13 is also extended forward, and these electrodes are in contact with a conductive portion 19a formed in the sealing material 19 located at the boundary between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. Similarly, the short side of the front electrode 13 of unit U13 is extended forward, and the short side of the front counter electrode 14 of unit U12 is also extended forward. Furthermore, the short side of the front electrode 13 of unit U12 is extended forward, and the short side of the front counter electrode 14 of unit U11 is also extended forward. These electrodes are in contact with a conductive portion 19a formed in the sealing material 19 located at the boundary between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. As a result, units U11-U14 are connected in series.

[0040] Furthermore, in the second dye-sensitized solar cell module M2 shown in Figure 6, the rear short side of the counter electrode 14 of unit U24 is pulled out to the rear, and the rear short side of the electrode 13 of unit U23 is pulled out to the rear, and these electrodes are in contact with the conductive portion 19a formed in the sealing material 19 located at the boundary between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. Similarly, the rear short side of the counter electrode 14 of unit U23 is pulled out to the rear, and the rear short side of the electrode 13 of unit U22 is pulled out to the rear. Also, the rear short side of the counter electrode 14 of unit U22 is pulled out to the rear, and the rear short side of the electrode 13 of unit U21 is pulled out to the rear. These electrodes are in contact with the conductive portion 19a formed in the sealing material 19 located at the boundary between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. As a result, units U21-U24 are connected in series.

[0041] Furthermore, the short side of the front electrode 13 of unit U11 is extended forward, and the short side of the rear counter electrode 14 of unit U21 is extended backward. These electrodes then contact the conductive portion 19a formed in the sealing material 19 located at the boundary between the first dye-sensitized solar cell module M1 and the second dye-sensitized solar cell module M2. As a result, unit U11 and unit U21 are connected in series. That is, each unit of the first dye-sensitized solar cell module M1 and each unit of the second dye-sensitized solar cell module M2 are connected in series.

[0042] In Figure 6, a compact dye-sensitized solar cell can be provided by forming the conductive portion 19a on the inside of the dye-sensitized solar cell module, rather than on the outside. Here, in Figure 6, the dye-sensitized solar cell has a two-stage structure consisting of a first dye-sensitized solar cell module M1 composed of four units U11, U12, U13, and U14, and a second dye-sensitized solar cell module M2 composed of four units U21, U22, U23, and U24. However, the number of units constituting the dye-sensitized solar cell module is not limited to four, nor is the number of dye-sensitized solar cell modules limited to two.

[0043] Furthermore, in the example described above, a sealing material 19 is provided at the unit boundary. In contrast, as shown in Figures 7, 8, and 9, a sealing material 19 does not necessarily have to be provided at the unit boundary. Figure 7 is a configuration corresponding to Figure 2. Figure 8 is a configuration corresponding to Figure 5. Figure 9 is a configuration corresponding to Figure 6. In the configurations of Figures 7, 8, and 9, the electrolytic solution 18 is common to all units. However, since a sealing material 19 is not provided at the unit boundary, in the configurations of Figure 8 and Figure 9, a sealing material as a conductive portion 19a is provided only at the connection portion of the electrodes between units. This sealing material as a conductive portion 19a can be formed using the same process as the sealing material 19 formed on the outer circumference of the dye-sensitized solar cell 1. Thus, even with the configurations of Figures 7, 8, and 9, the same effects as those in Figures 2, 5, and 6 can be obtained.

[0044] Furthermore, as shown in Figure 6, the electrode leads for conductivity between units in a multi-stage dye-sensitized solar cell module do not necessarily have to be directed toward the encapsulant 19 provided at the boundary of the dye-sensitized solar cell module. For example, as shown in Figure 10, the electrode leads for conductivity between units in a multi-stage dye-sensitized solar cell module may be directed toward the encapsulant 19 provided on the outer periphery of the dye-sensitized solar cell. Figure 10 shows a four-stage dye-sensitized solar cell composed of four dye-sensitized solar cell modules M1-M4.

[0045] In Figure 10, conductive portions 19a and 19b are formed on the far side of the encapsulating material 19 that surrounds the four dye-sensitized solar cell modules. Conductive portions 19a and 19b are formed side by side in the longitudinal direction. The electrodes 13 and counter electrodes 14 of the first dye-sensitized solar cell module, which is located at the furthest back, are connected to the conductive portion 19a formed at the furthest back position. The electrodes 13 and counter electrodes 14 of the second dye-sensitized solar cell module M2, which is located at the next furthest back position, are connected to the conductive portion 19b formed at the next furthest back position.

[0046] Similarly, in Figure 10, conductive portions 19c and 19d are formed on the front side of the encapsulant 19 that surrounds the four dye-sensitized solar cell modules. Like conductive portions 19a and 19b, conductive portions 19c and 19d are also formed side by side in the longitudinal direction. The electrode 13 and counter electrode 14 of the fourth dye-sensitized solar cell module, which is positioned closest to the front, are connected to the conductive portion 19c formed at the closest front position. The electrode 13 and counter electrode 14 of the third dye-sensitized solar cell module M3, which is positioned next to the front, are connected to the conductive portion 19d formed at the next front position.

[0047] Even with the structure shown in Figure 10, the conductive portions 19a, 19b, 19c, and 19d can be formed using the same process as the encapsulant 19. Here, the number of dye-sensitized solar cell modules is not limited to four. Also, in the example shown in Figure 10, each unit of the first dye-sensitized solar cell module M1 and each unit of the second dye-sensitized solar cell module M2 are connected by the conductive portions 19a and 19b on the back side, and each unit of the third dye-sensitized solar cell module M3 and each unit of the fourth dye-sensitized solar cell module M4 are connected by the conductive portions 19c and 19d on the front side. Alternatively, the conductive portions may be formed together on one side of the encapsulant.

[0048] Furthermore, in Figure 10, the conductive portions 19a and 19b and conductive portions 19c and 19d are formed side by side in the longitudinal direction. In contrast, as shown in Figure 11A, the conductive portions 19a and 19b and conductive portions 19c and 19d may be formed side by side in the short direction. In this case, it is necessary to bypass the electrodes of different dye-sensitized solar cell modules that are led out to the conductive portions so that they do not come into contact with each other. Figure 11B is a cross-sectional view showing the structure of region A in Figure 11A. Figure 11C is a cross-sectional view showing the structure of region B in Figure 11A.

[0049] In the example shown in Figure 11A, the counter electrode 14 is not formed on the second substrate 12, as shown in Figures 11B and 11C, but is formed on the interlayer insulating film 14a formed on the second substrate 12. A conductive film 14b is formed on the second substrate 12. The conductive film 14b may be a metal film such as a molybdenum (MO)-based metal film or a chromium (Cr)-based metal film.

[0050] As shown in Figure 11B, the counter electrode 14 of unit U14 of the first dye-sensitized solar cell module M1 is connected to the conductive film 14b via a contact 14c. At least a portion of the conductive film 14b is extended to the far side of the encapsulant 19 and contacts the conductive portion 19b formed on the far side of the encapsulant 19. Similarly, at least a portion of the electrode 13 of unit U13 of the first dye-sensitized solar cell module M1 is extended to the far side of the encapsulant 19 and contacts the conductive portion 19b formed on the far side of the encapsulant 19. This connects unit U14 and unit U13 electrically.

[0051] Furthermore, as shown in Figure 11C, a portion 14d of the counter electrode 14 of unit U24 of the second dye-sensitized solar cell module M2 is extended to the back edge of the encapsulant 19 and contacts the conductive portion 19a formed on the back side of the encapsulant 19. Also, at least a portion 13a of the electrode 13 of unit U23 of the second dye-sensitized solar cell module M2 is extended to the back edge of the encapsulant 19 and contacts the conductive portion 19a formed on the back side of the encapsulant 19. In other words, units U24 and U23 contact the conductive portion 19a at different layers than units U14 and U13. Therefore, conductive connection between each unit is achieved without electrode contact between different modules.

[0052] In the configuration shown in Figure 11A, it is not necessary to arrange the conductive parts in a longitudinal direction. Therefore, the longitudinal thickness of the sealing material 19 is thinner compared to Figure 10.

[0053] Furthermore, in the embodiments and their modifications described above, one terminal is formed on the anode substrate and one on the cathode substrate. In contrast, the terminals may be formed together on either the anode substrate or the cathode substrate. For example, as shown in Figure 12A, the opposing electrodes 14 at both ends of the cathode substrate may be extended, and terminals 141 may be formed on each of the opposing electrodes 14. In this case, for example, a encapsulant 19 formed on the outermost periphery of the dye-sensitized solar cell 1 may be used to provide conductivity between the opposing electrode 14 on which the terminals 141 are formed and the electrode 13. As mentioned above, by mixing conductive particles into an ultraviolet-curing resin such as acrylic resin in the encapsulant 19, the encapsulant 19 can function as a conductive portion between the opposing electrode 14 for the terminals 141 and the electrode 13. Similarly, for example, as shown in Figure 12B, the electrodes 13 at both ends of the anode substrate may be extended, and terminals 131 may be formed on each of the electrodes 13. In this case as well, for electrical conductivity between the electrode 13 on which the terminal 131 is formed and the counter electrode 14, for example, a sealing material 19 formed on the outermost periphery of the dye-sensitized solar cell 1 may be used.

[0054] The present invention is not limited to the embodiments described above, and can be modified in various ways during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and in that case, the combined effects can be obtained. Moreover, the above embodiments include various inventions, and various inventions can be extracted by selecting combinations from the multiple constituent elements disclosed. For example, if the problem can be solved and effects obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, then the configuration with these deleted constituent elements can be extracted as an invention. [Explanation of Symbols]

[0055] 1 Dye-sensitized solar cell, 11 First substrate, 12 Second substrate, 13 Electrode, 14 Counter electrode, 15 Electron transport layer, 16 Light absorption layer, 16a Dye, 16b Electron collecting agent, 17 Catalyst layer, 18 Electrolyte, 19 Encapsulating material, 19a, 19b, 19c, 19d Conductive parts.

Claims

1. A first unit comprising: a first electrode formed on a first substrate; a first counter electrode formed on a second substrate positioned opposite the first substrate; a first light-absorbing layer formed between the first electrode and the first counter electrode, containing an electron-collecting agent and a dye; a first electrolyte; and a first catalyst layer. A second unit having a second electrode formed on the first substrate, a second counter electrode formed on the second substrate, a second light-absorbing layer formed between the second electrode and the second counter electrode containing an electron-collecting agent and a dye, a second electrolyte, and a second catalyst layer, It is equipped with, The first electrode and the second counter electrode are electrically connected by a conductive portion formed in a sealing material containing an ultraviolet-curing resin. The sealing material is provided between the first substrate and the second substrate so as to surround the first unit and the second unit, and seals the first unit and the second unit together with the first substrate and the second substrate. The conductive portion is formed by conductive particles mixed into at least a portion of the sealing material. Dye-sensitized solar cells.

2. The first electrode and the second counter electrode are electrically connected by two or more conductive portions. The dye-sensitized solar cell according to claim 1.

3. The aforementioned sealing material is A first sealing material is formed between the first substrate and the second substrate, and on the outer periphery of the first unit and the second unit, A second sealing material is formed between the first substrate and the second substrate at the boundary position between the first unit and the second unit, Includes, The conductive portion is formed by conductive particles mixed into at least a portion of the second sealing material. The dye-sensitized solar cell according to claim 1.

4. The present invention comprises a plurality of dye-sensitized solar cell modules, each including the first unit and the second unit, arranged in a direction perpendicular to the arrangement direction of the first unit and the second unit. The aforementioned sealing material is A first sealing material formed between the first substrate and the second substrate and on the outer periphery of the plurality of dye-sensitized solar cell modules, A second sealant formed at the boundary position of each dye-sensitized solar cell module, Includes, The conductive portion is formed by conductive particles mixed into at least a portion of the second sealing material. The dye-sensitized solar cell according to claim 1.

5. The present invention comprises a plurality of dye-sensitized solar cell modules, each including the first unit and the second unit, arranged in a direction perpendicular to the arrangement direction of the first unit and the second unit. The sealing material is formed between the first substrate and the second substrate, surrounding the plurality of dye-sensitized solar cell modules. The dye-sensitized solar cell according to claim 1.

6. The dye-sensitized solar cell according to claim 5, wherein the conductive portions for each of the dye-sensitized solar cell modules are formed in the sealing material in a direction perpendicular to the arrangement direction of the first unit and the second unit.

7. The conductive portions for each of the dye-sensitized solar cell modules are formed in the sealing material in a direction parallel to the arrangement direction of the first unit and the second unit. The first counter electrode and the second counter electrode are formed on the second substrate via an interlayer insulating film. The first counter electrode and the second counter electrode are connected to a conductive film formed on the second substrate via a contact. The conductive film is connected to the conductive portion. The dye-sensitized solar cell according to claim 5.

8. The conductive portion is formed by mixing conductive particles into the sealing material. The particle size of the conductive particles has a length of 0 μm or more and 5 μm or less relative to the distance between the first substrate and the second substrate. A dye-sensitized solar cell according to any one of claims 1 to 7.

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