JP5400273B2 - Dye-sensitized solar cell and composite device including the same - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell and a composite device including the same, and more particularly to a dye-sensitized solar cell in which a plurality of electrodes are connected in series and a composite device including the same.

  Conventionally, Si solar cells are mainly used as solar cells. The reason for this is that the Si PN junction, which is well-established with semiconductors and the like, is used so that it can be manufactured stably. On the other hand, compound satellites such as GaAs are used in artificial satellites for space applications. This is because the photoelectric conversion efficiency is higher than that of Si and the radiation resistance is higher.

  However, it is necessary to make a high-quality PN junction for the above-mentioned semiconductor-based solar cell, and it takes time to make a high-quality single crystal and an expensive film-forming apparatus. There is a problem that it takes a lot of processes and requires production cost and production time.

  In recent years, research and development of dye-sensitized solar cells have been actively conducted in place of these semiconductor solar cells. The dye-sensitized solar cell is a solar cell developed by Gretzell in Switzerland at the beginning of the 1990s, and its photoelectric conversion efficiency is theoretically larger than that of Si-based solar cells, and is easy to manufacture. It is expected to be the next generation solar cell, and research and development are actively conducted.

  The electromotive force of a dye-sensitized solar cell is normally about 0.6 V per cell. In order to actually drive a device using this, a plurality of devices are connected in series, and the voltage that the device drives It is necessary to. As a method for the series connection, there are a connection method using a conductive wire and a connection method using a partition wall between cells.

  A connection method using a conducting wire will be described with reference to FIG. FIG. 12 is a plan view of a conventional dye-sensitized solar cell. As shown in this figure, the dye-sensitized solar cell S0 has a plurality of dye-sensitized solar cells 112, 112,... Arranged in parallel between a substrate 101 and a substrate 110. And the conducting wire 113 is pulled out from one end of the transparent conductive film 102 of each dye-sensitized solar cell 112 and connected to one end of the positive electrode film 106 of the adjacent dye-sensitized solar cell 112 through the surface side of the substrate. Thereby, the dye-sensitized solar cell 112 is connected in series.

  This connection method is the simplest and most reliable method because it is sufficient to connect the positive and negative electrodes of adjacent cells using a conductive wire or the like. However, the connection work takes time and at the same time, since the lead wire extends outside the cell, there are safety problems such as touching and cutting the lead wire during use, and inconvenience that the appearance is not good. Moreover, since a conducting wire is connected from the electrode terminal on the front surface of the substrate to the electrode terminal on the back surface, a bent portion is generated in the conducting wire. For this reason, breakage or the like is likely to occur at the joint between the electrode terminal and the conductive wire, and there is a problem in safety from this point.

  On the other hand, as a method of connection using the partition walls between cells, there are connection methods called W-type and Z-type as shown in Patent Documents 1 to 3 below.

Among these, the W type is configured such that the positive electrode and the negative electrode of adjacent cells are alternately inverted, and two current collecting electrodes of the adjacent cells are shared, and a partition is provided between the positive electrode substrate and the negative electrode substrate. This is a method of automatically connecting each cell in series by injecting and sealing.
This method has the advantage of being relatively easy to create. However, in this connection method, since the positive electrode and the negative electrode are alternately inverted, the area of the cell on the transparent negative electrode side capable of taking in the light necessary for power generation is half of the entire cell area on either side. For this reason, only half of the cells can be received even if light is taken from either side of the substrate, and only half of the total cells function. Therefore, there is a problem that the overall photoelectric conversion efficiency is substantially halved and the cell output voltage is approximately halved.
In the W type, since the positive and negative of adjacent cells are alternately inverted, every other cell does not function. For this reason, there is also a problem that the overall output current is reduced as compared with a Z-type array in which all the cells function.
As described above, in the W-type dye-sensitized solar cell, since the positive electrode and the negative electrode are alternately arranged, there is a problem that the output voltage is reduced by half, the output current is also decreased, and the power generation characteristics are deteriorated.

  On the other hand, in the Z type, the positive electrode and negative electrode of each cell are arranged in common on one substrate side, and a wiring is formed through a partition wall between cells to connect end portions of adjacent cells. is there. In this method, since only the negative electrode is arranged on one substrate, if light is taken in from the negative electrode side, it can be received by all the cells, and all the arranged cells function. For this reason, in the Z type, the photoelectric conversion efficiency does not decrease unlike the W type, and good power generation characteristics are exhibited.

JP-A-8-306399 JP 2007-12377 A JP 2007-18862 A

  In the Z-type dye-sensitized solar cell, the positive and negative electrodes adjacent to each other are connected through the partition wall, so that a conductive part is formed inside the partition wall, and the conductive part is protected from a highly corrosive electrolyte. There is a need. However, it is technically difficult to manufacture such a partition wall, and a precise sealing technique for preventing liquid leakage and short circuit is necessary, which is technically difficult. It wasn't the way. In particular, when the cell is miniaturized, more advanced microfabrication technology for partition walls and more precise sealing technology are required, and it is necessary to introduce expensive equipment and take time and effort to manufacture the cell. . Even if series-connected cells can be fabricated, it is difficult to completely seal electrolyte leakage and avoid short circuiting due to the structure, resulting in a decrease in yield and variations in solar cell characteristics. It was.

  In addition, in the Z type, when a short circuit or the like occurs in the wiring in the partition after the opposing substrates are once bonded, the bonded substrate is peeled off to expose the internal wiring structure in order to repair it. After repair, it was necessary to bond the substrates again. As described above, the Z type has a disadvantage that the repair of the wiring becomes very difficult.

An object of the present invention is to provide a dye-sensitized solar cell that can obtain stable characteristics with a simple configuration in a dye-sensitized solar cell including a plurality of cells in which a positive electrode is formed on one side and a negative electrode on the other side. There is to do.
Furthermore, another object of the present invention is to provide a composite device that is less likely to be disconnected or short-circuited and can be driven stably.

According to the dye-sensitized solar cell of the present invention, the problem is that a plurality of dye-sensitized solar cells arranged opposite to each other and having at least one light-transmitting property and arranged in parallel between the substrates are provided. Each of the dye-sensitized solar cells is formed on the translucent substrate. A negative electrode made of a transparent conductive film, a positive electrode made of an electrode formed on the other side of the pair of substrates so as to face the negative electrode, and a photoelectric conversion layer formed between the negative electrode and the positive electrode In the positive electrode and the negative electrode, both end portions in the longitudinal direction extend to the outside of the partition portion, and each of the extended regions of the both end portions is an opposite electrode of the adjacent dye-sensitized solar cell. A plurality of the dye sensitizers by being electrically connected to It is solved by positive battery cells are connected in series.

In this way, each of the extended regions at both ends is electrically connected to the opposite electrode of the adjacent dye-sensitized solar cell, so that a plurality of dye-sensitized solar cells are connected in series. Therefore, it is not necessary to connect the adjacent electrodes with a conducting wire that passes outside the substrate, or with a wiring that penetrates the partition between the cells. Therefore, it is possible to provide a dye-sensitized solar cell having a simple wiring structure and stable battery characteristics with few disconnections.
Moreover, the positive electrode and the negative electrode have both ends in the longitudinal direction extending to the outside of the partition, and each of the extended regions of both ends is electrically connected to the opposite electrode of the adjacent dye-sensitized solar cell. Therefore, it is possible to conduct with the opposite electrode at both ends of the positive electrode and the negative electrode. Since the resistance of the positive electrode and the negative electrode is proportional to the length of the electrode, the resistance value is halved by conducting at both ends compared to the case of conducting with the opposite electrode at one end of the positive and negative electrodes. Thus, a solar cell with low battery loss and high battery characteristics can be obtained.

Further, the pair of electrodes of the positive electrode and the negative electrode includes a protruding portion that protrudes toward the other electrode that is electrically connected to the extended region, and the protrusion protrudes vertically from the front side of the substrate. when part viewed, a portion of the projecting portion overlaps with a portion of said issued the extension of the other electrode regions, in polymerization it becomes part, preferably and have been connected to the other electrode .

Thus, by providing a protrusion part, the distance of the edge part of a positive electrode and the edge part of the negative electrode of an adjacent dye-sensitized solar cell becomes small, and it becomes easy to form electrical connection between both. Therefore, it is possible to provide a dye-sensitized solar cell having a stable characteristic with a simple configuration.
In addition, since a part of the protruding part overlaps with a part of the extended region of the other electrode, by connecting this overlapping part, the distance between the protruding part and the end of the opposite electrode is the shortest distance. Can conduct. By doing so, the wiring portion can be shortened, and disconnection due to the length of the wiring portion is less likely to occur. Therefore, it is possible to provide a dye-sensitized solar cell having a simpler wiring structure and having stable battery characteristics in which disconnection or the like is unlikely to occur.

In this case, the positive electrode has the protruding portion in the extended region on one end side of the partition portion, and the negative electrode has the protruding portion in the extended region on the other end side of the partition portion. When that has a suitable.

Since it comprises in this way , a protrusion part will be provided in the edge part of both a positive electrode and a negative electrode, and it will conduct | electrically_connect with an opposite electrode in the both ends side of an electrode. For this reason, the electrode resistance of an electrode part becomes a half compared with the case where it conducts only on one side. Therefore, it is possible to provide a dye-sensitized solar cell with less battery loss due to electrical resistance of the electrode and high battery characteristics.

  The transparent conductive film is preferably a laminated transparent conductive film in which an ATO film in which tin oxide is doped with antimony is laminated on an ITO film in which tin is doped into indium oxide.

  Such a laminated transparent conductive film has a low electric resistance and a small change in the electric resistance due to temperature, and therefore, a dye-sensitized solar cell with high photoelectric conversion efficiency can be produced.

  The transparent conductive film is preferably formed by a sputtering method.

  In this way, by forming the transparent conductive film by the sputtering method, the film thickness and optical characteristics of the transparent conductive film can be adjusted to desired ones, so the characteristics of the dye-sensitized solar cell can be set arbitrarily. Can do.

  The dye-sensitized solar cell is a composite device composed of a dye-sensitized solar cell and a device connected to the dye-sensitized solar cell. A battery is preferred.

  By setting it as such a structure, the composite apparatus provided with the dye-sensitized solar cell which has a simple structure and has the stable characteristic as a power supply device can be provided.

According to the dye-sensitized solar cell of the present invention, each cell is connected to the opposite electrode of the adjacent dye-sensitized solar cell at the end, so that the dye-sensitized with stable characteristics with a simple configuration A solar cell can be provided.
In addition, since each of the extended regions at both ends is electrically connected to the opposite electrode of the adjacent dye-sensitized solar cell, a plurality of dye-sensitized solar cells are connected in series. Adjacent electrodes need not be connected by a conductive wire passing outside the substrate or connected by wiring penetrating the partition between cells. Therefore, it is possible to provide a dye-sensitized solar cell having a simple wiring structure and stable battery characteristics with few disconnections.
Moreover, the positive electrode and the negative electrode have both ends in the longitudinal direction extending to the outside of the partition, and each of the extended regions of both ends is electrically connected to the opposite electrode of the adjacent dye-sensitized solar cell. Therefore, it is possible to conduct with the opposite electrode at both ends of the positive electrode and the negative electrode. Since the resistance of the positive electrode and the negative electrode is proportional to the length of the electrode, the resistance value is halved by conducting at both ends compared to the case of conducting with the opposite electrode at one end of the positive and negative electrodes. Thus, a solar cell with low battery loss and high battery characteristics can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the members, arrangement, configuration, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.

  1-11 is a figure for demonstrating the dye-sensitized solar cell which concerns on one Embodiment of this invention, FIG. 1 is a top view of the dye-sensitized solar cell which concerns on 1st Embodiment, FIG. 1 is a cross-sectional view of the dye-sensitized solar cell of FIG. 1, FIG. 3 is an electrode pattern diagram of the positive electrode substrate side and the negative electrode substrate side of the dye-sensitized solar cell according to the first embodiment, and FIG. FIG. 5 is a cross-sectional view taken along a line cc and a cross-sectional view taken along a line dd of the dye-sensitized solar cell of FIG. 1, and FIG. 6 is a dye according to the second embodiment. FIG. 7 is a plan view of a dye-sensitized solar cell according to the third embodiment, and FIG. 8 is an electrode of a positive electrode substrate and a negative electrode substrate of the dye-sensitized solar cell according to the third embodiment. FIG. 9 is an ee sectional view of the dye-sensitized solar cell of FIG. 7, and FIG. 10 is a plan view of the dye-sensitized solar cell according to the fourth embodiment. FIG. 11 is a f-f sectional view of a dye-sensitized solar cell of FIG. 10.

As shown in FIG. 1, the serial connection type dye-sensitized solar cell S <b> 1 includes a substrate 1 and a substrate 10 disposed to face the substrate 1. Between the substrate 1 and the substrate 10, a plurality of dye-sensitized solar cells 12 each having a band shape are arranged in parallel. The dye-sensitized solar cells 12 are connected in series.
In this figure, the lower end portion of the transparent conductive film 2 which is originally invisible cannot be seen as “end portion 2b”. Similarly, the edge part of the dye-sensitized solar cell 12 is shown as "edge part 12a".

As shown in FIG. 2, each dye-sensitized solar cell 12 includes a transparent conductive film 2, a titanium oxide layer 3, a dye 4 adsorbed on the titanium oxide layer 3, an electrolyte layer 5, a positive electrode film 6, and a partition. Part 7 is a main component. The titanium oxide layer 3, the dye 4, and the electrolyte layer 5 correspond to the photoelectric conversion layer of the present invention.
Further, the substrate 1 is formed with the negative electrode pattern shown in FIG. 3A, and the substrate 10 is formed with the positive electrode pattern shown in FIG.

The substrate 1 is a plate-like member having a transparent conductive film 2 formed on the surface. The material of the substrate 1 is selected from appropriate materials that can form the transparent conductive film 2 on the surface and have transparency to the extent that light is received by the transparent conductive film 2. As such a material, for example, a material capable of transmitting a predetermined amount of light, such as a glass substrate, a quartz substrate, a resin substrate, or an optical crystal substrate, is used. Particularly preferred is a non-alkali glass not containing an alkali element such as Na or a quartz substrate having high heat resistance. Further, in order to provide additional properties such as increasing transparency, preventing diffusion of alkali elements such as Na, increasing heat resistance, and providing gas barrier properties, the surface is made of SiO ₂ , TiO _2, etc. The thin film may be a substrate formed by a sputtering method.

The light transmittance of the substrate 1 is not particularly limited as long as it can transmit light into the inside of the dye-sensitized solar cell 12, but normally the average transmittance in the wavelength range of 400 to 900 nm is 10% or more. It is in the range of 99% or less, particularly in the range of 60% or more and 99% or less, and more preferably in the range of 80% or more and 99% or less.
Although it does not specifically limit as thickness of the board | substrate 1, Usually, it exists in the range of 100 micrometers or more and 5 mm or less, and especially the inside of the range of 500 micrometers or more and 2 mm or less is preferable.

The transparent conductive film 2 is a film having light permeability and conductivity. The transparent conductive film 2 constitutes the negative electrode of the dye-sensitized solar cell S1.
Similarly to the substrate 1 described above, the light transmittance of the transparent conductive film 2 is usually in the range of 10% to 99% of the average transmittance in the wavelength range of 400 nm to 900 nm, particularly 60% to 99%. The following range is preferable, and more preferably in the range of 80% to 99%.
Examples of the transparent conductive film 2 include transparent conductive films such as indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), and zinc oxide (ZnO), and transparent conductive films obtained by adding impurities to these transparent conductive films. Can be used.

  The transparent conductive film to which impurities are added includes ITO in which tin is added to indium oxide, ATO in which antimony is added to tin oxide, FTO in which tin oxide is doped with fluorine, AZO in which aluminum is added to zinc oxide, and gallium in zinc oxide. GZO or the like to which is added can be used.

  In the step of forming the titanium oxide layer 3 on the transparent conductive film 2, a titanium oxide paste is applied on the transparent conductive film 2 and baked at 400 to 500 ° C. as a desirable temperature. Therefore, the transparent conductive film 2 is preferably made of a material whose transmittance is not reduced by this firing step and whose resistance is not increased.

  In order to satisfy such conditions, there is a laminated transparent conductive film coated with ATO or FTO on FTO, ATO, ITO, etc. In order to improve the solar cell characteristics, these transparent conductive films 2 are transparent. It is preferable to use a conductive film.

  As shown in FIG. 3A, the transparent conductive film 2 of the present embodiment has a structure in which a plurality of electrodes each having a strip shape (rectangular shape) are arranged in parallel. These transparent conductive films 2 are formed using a mask or the like in which a plurality of strip-shaped openings are formed so as to form such a strip-shaped negative electrode pattern. In addition, as a method for forming the transparent conductive film 2 on the surface of the substrate 1, a known film forming technique such as a sputtering method, a vacuum evaporation method, an ion plating method, or the like can be used.

The substrate 10 is a plate-like member on which the positive electrode film 6 is formed. The material of the substrate 10 can be selected from the transparent materials as described for the substrate 1.
Note that, unlike the substrate 1, the substrate 10 is not necessarily a light-acquisition side, so it is not necessarily formed of a transparent material, and may be formed of a material with poor light transmission. Examples of such materials include various ceramics such as oxide ceramics and nitride ceramics.
The thickness of the substrate 10 is not particularly limited, but is usually in the range of 100 μm to 5 mm, and particularly preferably in the range of 500 μm to 2 mm.

The positive electrode film 6 is an electrode formed in a film shape with a conductive material. For the positive electrode film 6, a conductive metal film, the same material as that described for the transparent conductive film 2, or the like is used. In the case where the positive electrode film 6 is used in a portion where light needs to be transmitted, a transparent conductive film is used.
In order to increase the photoelectric conversion efficiency, the positive electrode film 6 is preferably made of Pt, Pd, Au or the like that has a catalytic action and is excellent in the resistance of the electrolytic solution layer 5 to the electrolytic solution. Connected to the positive electrode film 6 is a positive lead wire 8 for connection to an external load. Thus, since the positive electrode film 6 has both a catalytic function and a function as a collecting electrode, it is not necessary to separately provide a collecting electrode, and the configuration of the battery can be simplified.
In addition, as the positive electrode film | membrane 6, what does not show the catalytic action mentioned above but may function simply as a current collecting electrode. Examples of the material for the positive electrode film 6 include aluminum.

As shown in FIG. 3B, the positive electrode film 6 of this embodiment has a structure in which a plurality of electrodes each having a strip shape are arranged in parallel. Both ends of the positive electrode film 6 in the longitudinal direction extend to the outside of the partition part 7. A narrow portion is formed at one end of the positive electrode film 6, and a protruding portion 6 a that protrudes in the vertical direction from the narrow portion toward the adjacent dye-sensitized solar cell 12 is formed.
In the present embodiment, the protrusion 6a is formed only at the end on the same side (upper side in FIG. 1) in all of the plurality of strip-like positive electrode films 6. Thus, by providing the protruding portion 6a only on one side of the end portions, the size of the positive electrode film 6 can be reduced as compared with the case where the protruding portions are formed on both sides.

  The positive electrode film 6 is formed using a mask or the like in which a plurality of L-shaped openings are formed so as to have such an L-shaped positive electrode pattern. In addition, as a method of forming the positive electrode film 6 on the surface of the substrate 10, a known film forming technique such as a sputtering method, a vacuum evaporation method, an ion plating method, or the like can be used.

  The substrate 1 and the substrate 10 are disposed to face each other so that the transparent conductive film 2 and the positive electrode film 6 face each other. As shown in FIG. 1, in a plan view of the substrate 1, the transparent conductive film 2 and the positive electrode film 6 are disposed so as to be shifted from each other along the respective longitudinal directions (vertical direction in FIG. 1). That is, one end (the upper end in FIG. 1) of the transparent conductive film 2 is located above the upper end of the positive electrode film 6, and the other end of the positive electrode film 6 (in FIG. 1). The lower end portion protrudes below the lower end portion (indicated by 2b in the figure) of the transparent conductive film 2.

  As described above, with the substrate 1 and the substrate 10 shown in FIGS. 3A and 3B, as shown in FIG. 1, the substrate 1 and the substrate 10 are all connected so that all the dye-sensitized solar cells 12 are connected in series. A plurality of dye-sensitized solar cells 12 are formed between the two. Since the configuration of each dye-sensitized solar cell 12 is exactly the same as that of the single dye-sensitized solar cell 12 shown in FIG. 2, only the configuration of the single cell will be described below.

  As shown in FIG. 2, a titanium oxide layer 3 is formed on the surface side of the transparent conductive film 2. The titanium oxide layer 3 is formed by mixing a titanium oxide powder with a binder to form a paste, applying the fired paste onto the transparent conductive film 2, and firing it. The firing temperature may be 100 ° C. or higher, but it is preferably fired at 400 ° C. or higher in order to improve the sinterability between the titanium oxide particles and increase the photoelectric conversion efficiency.

  As the binder of the baked paste, an organic solvent, an acidic solution, or the like can be used. The crystal structure of the titanium oxide layer 3 is preferably an anatase type. Moreover, in order to have a favorable solar cell characteristic, it is preferable that the titanium oxide layer 3 has a pore structure including many small holes.

  The dye 4 is adsorbed on a part of the titanium oxide layer 3. As the dye 4, a dye that can efficiently absorb sunlight, that is, a dye having an absorption band from the near ultraviolet region to the near infrared region centering on the visible region is used. The dye 4 is dissolved in a solvent such as alcohol, and the substrate 1 formed up to the titanium oxide layer 3 is immersed in the dye 4 to be adsorbed on the pores of the titanium oxide layer 3.

In order to increase the photoelectric conversion efficiency, the dye 4 includes a Ru complex [RuL ₂ (NSC) ₂ ] (here, L L that can efficiently move electrons to the titanium oxide layer 3 when excited by light). = 4,4'-dicboxy-2,2'-bypyridine) or the like is preferably used.

  An electrolyte layer 5 is provided on the surface side of the dye 4. As the material for the electrolyte layer 5, a material that can supply electrons to the dye 4 and receive electrons at the positive electrode portion (positive electrode film 6) is used. Specific examples of such materials include an electrolytic solution in which lithium iodide and metallic iodine are dissolved in polyethylene glycol, and an electrolytic solution in which acetonitrile and ethylene carbonate are mixed.

Between the substrate 1 and the substrate 10, partition portions 7 for partitioning the respective dye-sensitized solar cells 12 are formed. The partition part 7 is a member for partitioning the entire outer peripheral part of the plurality of dye-sensitized solar cells 12, and is also a member that separates the respective dye-sensitized solar cells 12. In the space partitioned by the partitioning portion 7, the electrolytic solution of the electrolytic solution layer 5 is held between the titanium oxide layer 3 on which the dye 4 is adsorbed and the positive electrode film 6.
Resin, glass, etc. can be used as the material of the partition part 7. Specific examples of the resin include an epoxy resin and a urethane resin.

  A conductive paste 11 is disposed between the front end side of the protrusion 6 a of the positive electrode film 6 and the end of the transparent conductive film 2. The conductive paste 11 of the present embodiment is formed of a viscous material in which a conductive bonding agent containing a conductive metal powder such as copper is contained in an organic binder. For this reason, the transparent conductive film 2 and the positive electrode film 6 are electrically connected to each other, and since the viscosity is high, the conductive film is electrically connected to other electrodes, so that a short circuit is hardly generated.

Next, with reference to FIG. 4 and FIG. 5, the structure of the dye-sensitized solar cell S1 according to the present embodiment will be described in detail.
4 and 5 are aa to dd sectional views of the dye-sensitized solar cell S1 of FIG. 1, FIG. 4 (a) is an aa sectional view, and FIG. 4 (b) is a bb sectional view. FIG. 5C is a sectional view taken along line cc, and FIG. 5D is a sectional view taken along line dd.

  As shown in FIG. 4 (a), the tip side of the protruding portion 6a of the positive electrode film 6 (the region on the right side of each tip portion 6a in the figure) and a part of the transparent conductive film 2 face each other vertically. Is in position. The conductive paste 11 is applied along the up and down direction on the facing portion. That is, in the conductive paste 11, a part of the protruding part 6a and a part of the transparent conductive film 2 are connected with the shortest distance. As described above, the conductive paste 11 connects the transparent conductive film 2 and the positive electrode film 6 with the shortest distance, so that the connection portion formed of the conductive paste 11 can be narrowed. As a result, a short circuit with other electrodes due to the expansion of the connection portion is less likely to occur, the wiring structure is simplified, and stable battery characteristics are provided.

  As shown in FIG. 4B, the transparent conductive film 2 and the positive electrode film 6 are not wired in the region sealed by the partition portion 7, and the partition portion 7 is provided between them. . As shown in FIG.5 (c), the dye-sensitized solar cell 12 is provided in the center part of dye-sensitized solar cell S1. As shown in FIG. 5 (d), nothing is disposed between the transparent conductive film 2 and the positive electrode film 6 in the region outside the partition portion 7 where the conductive paste 11 is not provided. Absent.

Next, the manufacturing method of dye-sensitized solar cell S1 is demonstrated.
First, the transparent conductive film 2 is formed on the surface of the substrate 1 by a known film formation method such as a sputtering method. Next, a titanium oxide layer 3 is formed by applying and baking a baking paste containing titanium oxide powder on the surface of the transparent conductive film 2. Subsequently, the surface of the titanium oxide layer 3 is immersed in a solution containing the dye 4 to adsorb the dye 4 to the surface of the titanium oxide layer 3.
On the other hand, the positive electrode film 6 is formed on the surface of the substrate 10 by the sputtering method or the like in the same manner as the substrate 1.

Next, the partition part 7 is formed between the board | substrate 1 and the board | substrate 10, after inject | pouring electrolyte solution, it bonds together. At that time, as shown in FIG. 1, the patterns are bonded to each other with a slight shift along the longitudinal direction so that the end of each pattern is exposed by about several millimeters.
Finally, the conductive paste 11 is applied between the front end side of the protrusion 6 a of the positive electrode film 6 and the end of the transparent conductive film 2. Thereby, it can be connected in series without conducting wire.

Next, the dye-sensitized solar cell S2 according to the second embodiment will be described.
In the first embodiment described above, the positive electrode film 6 is provided with the protruding portion 6a and the transparent conductive film 2 is not provided with the protruding portion. However, in the present embodiment, the transparent conductive film 2 is provided with the protruding portion 2a and the positive electrode film 6 is provided with the positive portion. The electrode film 6 is not provided with a protruding portion.

  As shown in FIG. 6, the transparent conductive film 2 and the positive electrode film 6 are in positions shifted from each other along the longitudinal direction, and one end of the transparent conductive film 2 is at the end of the adjacent positive electrode film 6. A protruding portion 2a that protrudes toward is formed. When viewed from the front side of the substrate 1 in the vertical direction, the tip end portion of the protruding portion 2 a overlaps with a part of the end portion of the positive electrode film 6 of the adjacent dye-sensitized solar cell 12. Then, the conductive paste 11 is applied between the front end portion of the protruding portion 2a and the end portion of the positive electrode film 6, and both are conducted. Thus, even if a protrusion is provided at the end of the transparent conductive film 2, the dye-sensitized solar cells 12 can be connected in series.

Next, the dye-sensitized solar cell S3 according to the third embodiment will be described.
In the first and second embodiments described above, the protruding portion is formed only on one of the transparent conductive film 2 and the positive electrode film 6, but in this embodiment, the protruding portion is provided on both. .

As shown in FIG. 7, a protruding portion 2 a that protrudes toward the adjacent dye-sensitized solar cell 12 is formed at one end (the lower end portion of FIG. 7) of the transparent conductive film 2. In addition, a protruding portion 6 a that protrudes toward the dye-sensitized solar cell 12 adjacent to the opposite side is formed at one end of the positive electrode film 6 (the upper end portion in FIG. 7).
As shown in FIG. 8A, a plurality of transparent conductive films 2 are formed on the substrate 1. At one end of the transparent conductive film 2 (the lower end in FIG. 8A), a protruding portion 2a that protrudes toward the adjacent dye-sensitized solar cell 12 is formed.
On the other hand, as shown in FIG. 8B, a plurality of positive electrode films 6 are formed on the substrate 10. At one end of the positive electrode film 6 (the upper end in FIG. 8B), a protruding portion 6a that protrudes toward the adjacent dye-sensitized solar cell 12 is formed.

FIG. 9 is a cross-sectional view taken along the line ee of FIG. As shown in FIG. 9, the conductive paste 11 is applied between the protruding portion 2a of the transparent conductive film 2 and the end portion of the positive electrode film 6 of the dye-sensitized solar cell 12 adjacent thereto. ing. Thereby, the transparent conductive film 2 and the positive electrode film 6 are electrically connected.
In this way, by providing the transparent conductive film 2 and the positive electrode film 6 with the protruding portions, the transparent conductive film 2 and the positive electrode film 6 are electrically connected to the opposite electrodes on both ends. Here, the resistance of the transparent conductive film 2 and the positive electrode film 6 is proportional to the length of the electrode. For this reason, compared with the case where it conducts with the opposite electrode at one end side of the transparent conductive film 2 and the positive electrode film 6 as in the first and second embodiments, the resistance value is halved by conducting at both ends. . Thereby, the internal cell resulting from resistance of the transparent conductive film 2 or the positive electrode film 6 is few, and it can be set as a solar cell with a high battery characteristic.

Next, the dye-sensitized solar cell S4 according to the fourth embodiment will be described.
In any of the first to third embodiments described above, when viewed from the front side of the substrate 1 in the vertical direction, the opposite electrode in the dye-sensitized solar cell 12 in which the tip of the protruding portion of one of the electrodes is adjacent. In this structure, the conductive paste 11 is disposed in the overlapping region. However, as long as conduction between the positive electrode and the negative electrode can be ensured, the protruding portion and the end portion of the opposite electrode do not necessarily overlap as described above.

  As shown in FIG. 10, the dye-sensitized solar cell S4 of this embodiment is a dye-sensitized solar cell adjacent to the protruding portion 6a of the positive electrode film 6 when viewed in the vertical direction from the front side of the substrate 1. 12 does not overlap with a part of the end of the transparent conductive film 2, and a predetermined gap is left between the tip of the protruding portion 6 a and the side of the end of the transparent conductive film 2.

  As shown in FIG. 11, the conductive paste 11 is disposed along the oblique direction between the protrusion 6 a and the end of the transparent conductive film 2, and between the transparent conductive film 2 and the positive electrode film 6. Continuity is ensured. The conductive paste 11 is preferably made of a material having a viscosity high enough to adhere only to the opposite electrode of the adjacent dye-sensitized solar cell 12 and not to other electrodes.

Thus, in the dye-sensitized solar cell S4 of the present invention, as described above, a part of the protruding part of the electrode does not necessarily overlap with a part of the end part of the opposite electrode. By disposing the conductive paste 11 between the electrodes that do not become conductive, the conductive paste 11 may drip under the influence of gravity and may short-circuit with other electrodes other than the opposite electrode. For this reason, as in the first to third embodiments, it is possible to connect the electrodes at the shortest distance by the conductive paste when the protruding portion of one electrode and the end of the opposite electrode overlap each other. It is preferable that a short circuit due to dripping of the conductive paste 11 does not occur.
In each of the above-described embodiments, the protruding portion has a shape protruding vertically from the main body of the electrode. However, the protruding portion is not limited to the protrusion protruding in the vertical direction, and is adjacent to the dye-sensitized solar cell. Any shape that projects toward the cell 12 may be used. For example, the shape in plan view may be a curved shape such as a C shape or an S shape.
Moreover, in each said embodiment, although the shape of the transparent conductive film 2 and the positive electrode film 6 was made into strip | belt shape, it is not limited to this, What kind of shape, such as a circle, a square, a triangle, may be sufficient.

Next, embodiments of the present invention will be described with reference to the drawings.
Example 1
The Example which produced dye-sensitized solar cell S1 shown in FIG. 1 is demonstrated.
First, a positive electrode film 6 serving as a positive electrode was formed on a substrate 10 made of soda lime glass having a length of 100 mm, a width of 100 mm, and a thickness of 1 mm. The positive electrode film 6 was formed by a DC magnetron sputtering method using a platinum (Pt) target. Film formation was performed with a DC power of 0.6 kW and no heating to form a 0.3 μm Pt thin film.

  In the formation of the Pt film, the Pt film was formed on the substrate 10 using a mask having a predetermined shape so as to have a pattern having an L-shaped end as shown in FIG. The patterns of the six Pt films were formed at a predetermined interval (about 5 mm) so as to be insulated from each other. The pattern of the six Pt films is formed by producing six dye-sensitized solar cells 12 on the substrate 1 corresponding to each Pt film and connecting them in series to increase the electromotive force. Because.

The substrate 1 on the negative electrode side was made of soda lime glass having a length of 100 mm, a width of 100 mm, and a thickness of 1 mm, similarly to the positive electrode side. As will be described later, since the substrate 1 is baked at 500 ° C. in the subsequent steps, impurities such as alkali elements and oxygen contained in the glass are prevented from diffusing and the heat resistance of the glass is improved. Before the transparent conductive film 2 is formed, a silicon oxide (SiO ₂ ) thin film is first formed on the glass substrate 1. The SiO ₂ film was formed by introducing an oxygen gas by an RF magnetron sputtering method using a Si semiconductor target. The RF power was 1 KW, and the film was formed without heating. This formed a 0.05 .mu.m SiO ₂ thin film.

Next, a transparent conductive film is formed by forming an indium oxide (ITO) film doped with tin and a tin oxide (ATO) film doped with antimony in this order on the substrate 1 on which the SiO ₂ thin film is formed. 2 was formed.
During the film formation, ITO and ATO sintered targets were used, respectively, and the film was formed by a DC magnetron sputtering method with a DC power of 1.0 kW and a film formation temperature of 300 ° C. The film thicknesses of the formed ITO thin film and ATO thin film are 0.3 μm and 0.1 μm, respectively. The laminated transparent conductive film had a resistance value of 4.5Ω / □.

The reason why the ATO film is formed on the ITO film is to suppress an increase in the resistance of the transparent conductive film 2 during the titanium oxide (TiO ₂ ) baking process described below.
When forming the ITO film and the ATO film, six strip-shaped transparent conductive films 2 (ITO / ATO films) were formed as shown in FIG. 3A using a mask having a predetermined shape.

  Next, a viscous liquid in which titanium oxide powder is dissolved in an acidic solution and applied in paste form is applied onto the six strip-shaped transparent conductive films 2 by the squeegee method, dried, and then placed in an electric furnace. Firing was performed at 500 ° C. for 1 hour. Thereby, the titanium oxide layer 3 was formed on the surface of the transparent conductive film 2.

Next, a step of adsorbing the dye 4 to the titanium oxide layer 3 was performed. First, the dye 4 containing the Ru complex was dissolved with alcohol in a petri dish. Subsequently, the baked substrate 1 was taken out from the electric furnace, and the substrate 1 was immersed in a petri dish in which the dye was dissolved overnight, so that the dye 4 was adsorbed on the surface of the titanium oxide layer 3.
The next day, the substrate 1 was taken out of the petri dish, and the pigment 4 other than the titanium oxide layer 3 was wiped clean. An adhesive was applied between the peripheral part of the substrate 1 and the six strip-shaped dye-sensitized solar cells 12 to form the partition part 7. In this example, the partition part 7 was formed with the epoxy resin.

  Next, as an electrolytic solution layer 5, lithium iodide and metallic iodine were dissolved in polyethylene glycol to prepare an iodine solution, and this iodine solution was suspended in each cell partitioned into six by the partition portion 7. Thereafter, the substrate 1 and the substrate 10 are overlapped so that the ends of the six Pt positive electrode films 6 and the ITO / ATO transparent conductive film 2 are exposed by several mm as shown in FIG. It was. Thereby, the electrolyte solution of the electrolyte solution layer 5 was sealed between the substrate 1 and the substrate 10 by the partition portion 7.

  Finally, as shown in FIG. 4A, a conductive paste is applied in the gap between the end of the adjacent exposed L-shaped positive electrode film 6 and the end of the transparent conductive film 2 to connect them in series. It was. Further, as shown in FIGS. 4A and 4B, conductive wires 11 are fixed to the exposed positive electrode film 6 and transparent conductive film 2 of the left and right dye-sensitized solar cells 12 with a conductive paste 11, respectively. By fixing, the positive electrode lead wire 8 and the negative electrode lead wire 9 were drawn out.

  As described above, a dye-sensitized solar cell S1 in which six dye-sensitized solar cells 12 were connected in series without wiring was produced. The power generation characteristics of the solar cell were measured using a solar simulator as a light source and an IV curve tracer as a current-voltage measuring device. As a comparative example, the power generation characteristics were examined by the same method for an example in which the six dye-sensitized solar cells 12 were not connected in series and each was configured independently.

As a result, in the dye-sensitized solar cell (comparative example) in which the dye-sensitized solar cells 12 are not connected in series, the open circuit voltage is 0.68 V, the short-circuit current is 12.48 mA / cm 2, and the photoelectric conversion efficiency is about 5. It was 6%.
On the other hand, in the dye-sensitized solar cell (Example) in which the dye-sensitized solar cells 12 are connected in series, the open-circuit voltage of the entire solar cell is 3.8 V, the short-circuit current is 12.21 mA, and the photoelectric conversion efficiency is about 5.5%. there were.

  In order to confirm that it actually functions as a solar cell, when it was connected to a calculator and irradiated with light, it was confirmed that the calculator worked. For this reason, it turned out that the dye-sensitized solar cell S1 of a present Example has sufficient electromotive force to operate a device.

  As described above, it was confirmed that the dye-sensitized solar cell S1 of this example can be easily manufactured and sufficiently functions as a power source.

It is a top view of the dye-sensitized solar cell which concerns on 1st Embodiment. It is sectional drawing of the dye-sensitized solar cell of FIG. It is an electrode pattern figure of the positive electrode substrate side and negative electrode substrate side of the dye-sensitized solar cell which concerns on 1st Embodiment. It is aa sectional drawing and bb sectional drawing of the dye-sensitized solar cell of FIG. It is cc sectional drawing and dd sectional drawing of the dye-sensitized solar cell of FIG. It is a top view of the dye-sensitized solar cell which concerns on 2nd Embodiment. It is a top view of the dye-sensitized solar cell which concerns on 3rd Embodiment. It is an electrode pattern figure of the positive electrode substrate side and negative electrode substrate side of the dye-sensitized solar cell which concerns on 3rd Embodiment. It is ee sectional drawing of the dye-sensitized solar cell of FIG. It is a top view of the dye-sensitized solar cell which concerns on 4th Embodiment. It is ff sectional drawing of the dye-sensitized solar cell of FIG. It is a top view of the conventional dye-sensitized solar cell.

Explanation of symbols

1 Substrate 2 Transparent conductive film (negative electrode)
2a Projection 2b End 3 Titanium oxide layer (photoelectric conversion layer)
4 Dye (photoelectric conversion layer)
5 Electrolyte layer (photoelectric conversion layer)
6 Positive electrode film (positive electrode)
6a Protrusion 7 Partition 8 Positive electrode lead 9 Negative electrode lead 10 Substrate 11 Conductive paste 12 Dye-sensitized solar cell 12a End 101 Substrate 102 Transparent conductive film 106 Positive electrode film 110 Substrate 112 Dye-sensitized solar cell 113 Conductor S0 Conventional dye-sensitized solar cell S1 to S4 Dye-sensitized solar cell

Claims (6)

A pair of substrates disposed opposite to each other, at least one of which has translucency;
A plurality of dye-sensitized solar cells arranged in parallel between the substrates;
A partition that partitions the outer periphery of the plurality of dye-sensitized solar cells,
Each of the dye-sensitized solar cells is
A negative electrode composed of a transparent conductive film formed on the light-transmitting substrate;
A positive electrode formed on the other side of the pair of substrates to face the negative electrode;
A photoelectric conversion layer formed between the negative electrode and the positive electrode,
The positive electrode and the negative electrode have both ends in the longitudinal direction extending to the outside of the partition part,
Each of the extended regions of the both ends is electrically connected to the opposite electrode of the adjacent dye-sensitized solar cell, so that the plurality of dye-sensitized solar cells are connected in series. The dye-sensitized solar cell characterized by the above-mentioned. The pair of electrodes of the positive electrode and the negative electrode includes a protruding portion that protrudes toward the other electrode that is electrically connected to the extended region,
When the protrusion is viewed from the front side of the substrate in the vertical direction, a part of the protrusion overlaps with a part of the extended region of the other electrode, and the overlap part The dye-sensitized solar cell according to claim 1, wherein the dye-sensitized solar cell is connected to the other electrode. The positive electrode has the protruding portion in the extended region on one end side of the partition portion,
The dye-sensitized solar cell according to claim 2, wherein the negative electrode has the protruding portion in the extended region on the other end side of the partition portion.   The transparent transparent conductive film is a laminated transparent conductive film in which an ATO film in which tin oxide is doped with antimony is laminated on an ITO film in which tin is doped with indium oxide. 2. The dye-sensitized solar cell according to item 1.   The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the transparent conductive film is formed by a sputtering method. A composite-type device composed of a dye-sensitized solar cell and a device connected to the dye-sensitized solar cell,
The said dye-sensitized solar cell is a dye-sensitized solar cell of any one of Claims 1-3, The composite type apparatus characterized by the above-mentioned.

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