JP4666926B2 - Dye-sensitized solar cell - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell in which a plurality of dye-sensitized photoelectric conversion elements are connected, and a method for manufacturing the same.

  A photoelectric conversion element in which a semiconductor layer carrying a dye and an electrolyte are provided between a transparent electrode and a counter electrode and the periphery is sealed with a sealing material such as a resin is known as a dye-sensitized photoelectric conversion element. In such a photoelectric conversion element, a current extraction part is provided between the transparent electrode and the counter electrode. When a plurality of photoelectric conversion elements are connected, a metal material is used between the current extraction parts provided in each photoelectric conversion element. Connected.

As a method for producing such a dye-sensitized photoelectric conversion element, the following method has been proposed.
A transparent conductive layer is formed on a transparent substrate (transparent electrode), and a plurality of semiconductor layers carrying pigments are separately provided on the transparent substrate, and each semiconductor layer is surrounded by a sealing material (side wall), on which A substrate having a counter electrode formed on the surface is set. A plurality of photoelectric conversion elements are formed between the transparent substrate and the substrate by filling an electrolyte in a space provided with the semiconductor layer surrounded by the transparent electrode, the counter electrode, and the sealing material. .

  Next, a conductive paste containing a metal material is applied between adjacent photoelectric conversion elements and baked to form a conductive electrode. As a result, the conductive electrode is formed so as to be in contact with the current extraction portion on the transparent electrode side of one adjacent photoelectric conversion element and the current extraction portion on the counter electrode side of the other photoelectric conversion element, and adjacent to each other. The photoelectric conversion elements are electrically connected. According to this method, it is possible to simultaneously produce the photoelectric conversion elements on the same substrate without individually producing the photoelectric conversion elements.

  Thus, in the conventional dye-sensitized solar cell, the current extraction part on the transparent electrode side of one photoelectric conversion element that is adjacent to each other and the counter electrode side of the other photoelectric conversion element Therefore, it was necessary to form it so as to be in contact with both of the current extraction portions.

  However, in the prior art, it is difficult to bring the conductive electrode into contact with the current extraction portion of both photoelectric conversion elements that are adjacent to each other without any gap, and sufficient electrical continuity cannot be ensured. . Further, since the conductive electrode is required to have high conductivity, the conductive electrode is usually formed from silver, copper or the like. On the other hand, the conductive electrode is installed in a predetermined space between adjacent photoelectric conversion elements surrounded by a sealing material (side wall), but an electrolyte has oozed out from between the sealing material (side wall). In this case, there is a problem in that the conductive electrode is affected by the electrolyte.

  Further, in order to bring the conducting electrode into contact with the current extraction portion as much as possible, it is necessary to increase the thickness of the conducting electrode to some extent and sandwich it, and there is a problem that the thickness of the photoelectric conversion element cannot be reduced. there were.

  The present invention solves the above-described problems and provides a structure and a manufacturing method of a dye-sensitized solar cell capable of easily, reliably and electrically connecting a plurality of dye-sensitized photoelectric conversion elements. To do.

In order to achieve the above object, the present invention provides:
A plurality of photoelectric conversion elements composed of a transparent electrode, a semiconductor layer carrying a dye, a first electrolyte, and a counter electrode are formed on the same substrate, and the plurality of photoelectric conversion elements are adjacent to each other. to spacing between elements is sealed to hold the space between each adjacent photoelectric conversion elements two with a sealing material, the space in which the formed between the two sealing member , A redox electrode is provided on the transparent electrode and the counter electrode of the adjacent photoelectric conversion element, and the redox electrodes are arranged so as not to contact each other and to contact with the counter electrode or the transparent electrode existing opposite to each other. In addition, the present invention relates to a dye-sensitized solar cell, wherein the plurality of photoelectric conversion elements are electrically connected to each other by further providing a second electrolyte layer. The first electrolyte and the second electrolyte can be made of the same electrolyte, or can be made of different electrolytes.

  According to the present invention, in addition to filling the space formed by the transparent electrode and the counter electrode formed with a plurality of semiconductor layers constituting each photoelectric conversion element with the electrolyte, each photoelectric conversion element is also predetermined. It is designed to be electrically connected with the electrolyte. Therefore, the adjacent photoelectric conversion elements can be electrically connected without the need for providing a separate conducting electrode as in the prior art. That is, adjacent photoelectric conversion elements can be electrically connected easily and reliably, and the intended dye-sensitized solar cell can be configured.

  In a preferred embodiment of the present invention, an oxidation-reduction electrode for electrolyte made of carbon or metal is formed on at least one of the current extraction portions provided on the transparent electrode and the counter electrode. As a result, an oxidation-reduction reaction of the electrolyte via the oxidation-reduction electrode becomes active, and electrical connection between the adjacent photoelectric conversion elements can be promoted and electrical conduction can be further improved.

  Moreover, when providing the said oxidation reduction electrode, it is preferable to carry | support a oxidation reduction catalyst with respect to this electrode. Thereby, the oxidation-reduction reaction of the electrolyte at the oxidation-reduction electrode becomes more active, electrical connection between adjacent photoelectric conversion elements can be further promoted, and electrical conduction can be further improved. Furthermore, the redox electrode is preferably porous. In this case, the surface area of the redox electrode is increased, and the amount of the redox catalyst supported can be increased. Therefore, electrical continuity between adjacent photoelectric conversion elements can be further improved.

  As described above, according to the present invention, a plurality of photoelectric conversion elements are electrically connected by an electrolyte, and a conventional conductive electrode is not used. Thus, the conducting electrode is not attacked by the electrolyte. In addition, it is not required to increase the thickness of the conductive electrode to some extent in order for the conductive electrode to contact the current extraction portion. Therefore, it is possible to easily and reliably electrically connect a plurality of dye-sensitized photoelectric conversion elements, and to provide a sufficiently thinned dye-sensitized solar cell structure and manufacturing method. .

  Details of the present invention, as well as other features and advantages, are described in detail below. However, the present invention is not limited to the embodiments described below.

  FIG. 1 is a configuration diagram showing an example of the dye-sensitized solar cell of the present invention. A dye-sensitized solar cell 10 shown in FIG. 1 includes a transparent electrode substrate 11 and a counter electrode substrate 12 provided so as to face the transparent electrode substrate 11. The transparent electrode substrate 11 includes a transparent substrate 111 and a transparent electrode 112 formed on the transparent substrate 111. The counter electrode substrate 12 is composed of a predetermined substrate 121 and two-layered conductive layers 122 and 123 that are formed on the substrate 121 and constitute the counter electrode.

  Semiconductor layers 13-1 and 13-2 are formed on the transparent electrode 112, and the semiconductor layers 13-1 and 13-2 are embedded between the transparent electrode 112 and the counter electrode 122; 123. An electrolyte 18 is filled. The semiconductor layers 13-1 and 13-2 carry a predetermined dye (not shown).

  The transparent electrode 112, the counter electrode 122; 123, the semiconductor layer 13-1, and the electrolyte 18 constitute the first photoelectric conversion element 20, and the transparent electrode 112, the counter electrode 122; 123, the semiconductor layer 13-2, and the electrolyte. 18 constitutes a second photoelectric conversion element 30.

  Moreover, the 1st photoelectric conversion element 20 is sealed with the sealing material 14-1 provided in counter electrode 122; 123 (counter electrode board | substrate 12), and the 2nd photoelectric conversion element 30 is transparent electrode 112 ( It is sealed with a sealing material 14-2 provided on the transparent electrode substrate 11).

  In the space formed by the sealing materials 14-1 and 14-2, the transparent electrode 112 is provided with the transparent electrode side current extraction part 15, and the counter electrode 122; 123 is provided with the counter electrode side current extraction part 16. It has been. Further, the current extraction parts 15 and 16 are provided with a pair of redox electrodes 17 facing each other. The pair of redox electrodes 17 are arranged so as to face each other with a predetermined distance without contacting each other. Moreover, it is provided so as not to contact the transparent electrode side current extraction part 15 of the transparent electrode 112 and the counter electrode side current extraction part 16 of the counter electrode 122;

  In the solar cell 10 shown in FIG. 1, an electric current is passed through the transparent electrode 112, the counter electrode 122; 123, the semiconductor layers 13-1 and 13-2, the redox electrode 17 and the electrolyte 18 as indicated by arrows in the drawing. The first photoelectric conversion element 20 and the second photoelectric conversion element 30 are electrically connected to each other in series.

  That is, in the dye-sensitized solar cell 10 shown in FIG. 1, the first photoelectric conversion element 20 and the second photoelectric conversion element 30 are electrically connected in series via the electrolyte 18. Therefore, unlike the prior art, the adjacent photoelectric conversion elements 20 and 30 can be electrically connected by the electrolyte 18 itself that constitutes the photoelectric conversion elements 20 and 30 without providing a separate conducting electrode. That is, adjacent photoelectric conversion elements can be easily and reliably electrically connected.

  In the dye-sensitized solar cell 10 shown in FIG. 1, power is generated through the following steps in each photoelectric conversion element. That is, when light in a predetermined wavelength region is incident from the outside, the dye supported on the semiconductor layers 13-1 and 13-2 is excited by absorbing the light, and the generated electrons are converted into the semiconductor layer 13-. Awarded to 1 and 13-2. Next, the electrons flow through the transparent electrode 112 in the order of the transparent electrode side current extraction part 15 → the oxidation / reduction electrode 17 → the electrolyte 18 → the oxidation / reduction electrode 17 → the counter electrode side current extraction part 16 and reach the counter electrodes 122 and 123. On the other hand, the dye is supplied with electrons from the counter electrodes 122; 123 through the electrolyte 18, and enters a steady state. Such a process is defined as one cycle, and usually, such a cycle is repeated a plurality of times, whereby continuous power generation is executed.

  In the dye-sensitized solar cell 10 illustrated in FIG. 1, a pair of redox electrodes 17 is provided in the current extraction units 15 and 16. In this case, the oxidation-reduction reaction of the electrolyte 18 through the oxidation-reduction electrode 17 becomes active, the electrical connection between the adjacent photoelectric conversion elements 10 and 20 can be promoted, and the electrical conduction can be further improved.

  As described above, the pair of redox electrodes 17 are arranged so as to face each other at a predetermined distance without contacting each other, and the transparent electrode-side current of the transparent electrode 112 that is opposed to each other. It is provided so as not to contact the extraction part 15 and the counter electrode side current extraction part 16 of the counter electrode 122; 123. Thus, since the redox electrodes 17 are not necessarily required to contact each other and to the opposing current extraction portion, the production of the redox electrode 17 is facilitated and its reliability is improved.

  However, the gap between the pair of redox electrodes 17 is preferably 0.1 μm to 50 μm. In this case, the influence of the gap on the current flowing in the dye-sensitized solar cell 10 can be removed, and the current flow is not hindered.

  As the transparent substrate 111, a general-purpose substrate such as a glass substrate can be used. The transparent electrode 112 is composed of tin oxide, fluorine-doped tin oxide, ITO, ATO, zinc oxide, aluminum-doped zinc oxide, or a light-transmissive transparent conductive layer in which a coating of tin oxide or fluorine-doped tin oxide is provided on the surface thereof. Can be formed. Further, conductive glass having a conductive layer such as fluorine-doped tin oxide on the surface can be used as the transparent electrode substrate 11.

  The substrate 121 can be made of glass, plastic, or the like. The conductive layers 122 and 123 can be made of Pt, C, Ni, Cr, stainless steel, fluorine-doped tin oxide, ITO, or the like. The counter electrode substrate 12 can also be made of conductive glass in which a conductive layer such as fluorine-doped tin oxide is provided on the surface as described above.

  The semiconductor layers 13-1 and 13-2 can be made of a known semiconductor such as an oxide semiconductor, a sulfide semiconductor, a selenide semiconductor, a telluride semiconductor, an arsenide semiconductor, a phosphide semiconductor, or a silicon-based semiconductor. As the dye supported on the semiconductor layers 13-1 and 13-2, a ruthenium metal complex can be preferably used, and among them, a ruthenium bipyridine complex is preferable.

The electrolyte 18 can be a solid or a liquid. Specifically, an iodine-based electrolyte, the bromine-based electrolyte, selenium-based electrolyte, it is possible to employ a sulfur-based electrolyte such as various electrolytes, I _2, LiI, acetonitrile dimethylpropyl imidazolium iodide, etc., methoxyacetonitrile A solution or the like dissolved in an organic solvent such as propylene carbonate or ethylene carbonate is preferably used.

  The sealing materials 14-1 and 14-2 are made of an insulating material, and can be composed of, for example, an epoxy resin, a fluorine-containing resin, an ionomer resin or the like alone or in combination.

  The oxidation-reduction electrode 17 is not particularly limited as long as it is a conductive substance and is not affected by the electrolyte 18. Moreover, the layer containing a redox electrode material should just be formed in the at least one part. Examples of the redox electrode material include C, Ni, Cr, In, Ti, Sn, and a mixture or composite of two or more thereof. In particular, C, Ni, Cr, and a mixture, composite or alloy of two or more of these are preferable because they are not corroded by the electrolyte 18, particularly iodine.

  In the conventional method of forming a conducting electrode, conduction is achieved by passing a current through the conducting electrode, so that the conducting electrode is required to have high conductivity, and only Ag, Cu, etc. can be used. According to the present invention, since conduction is achieved through the electrolyte, C, Ni, Cr, which could not be used as a conventional conduction electrode because of its relatively low conductivity while having the advantage of being hardly affected by the electrolyte. Etc. can be used as a redox electrode material.

  The redox electrode 17 preferably supports a redox catalyst. Thereby, the oxidation-reduction reaction of the electrolyte 18 in the oxidation-reduction electrode 17 becomes more active, the electrical connection between the adjacent photoelectric conversion elements 20 and 30 can be further promoted, and the electrical continuity can be further improved. At this time, the redox electrode 17 is preferably porous. In this case, the surface area of the redox electrode 17 is increased, and the amount of the redox catalyst supported can be increased. Therefore, the electrical continuity between the adjacent photoelectric conversion elements 20 and 30 can be further improved.

  Examples of the oxidation-reduction catalyst include one or two of Pt, Ag, Au, Pd, Rh, Ru, palladium oxide, palladium chloride, ruthenium oxide, ruthenium chloride, platinum oxide, and platinum chloride. The above can be used. Pt is particularly preferable.

  Next, a method for producing the dye-sensitized solar cell 10 shown in FIG. 1 will be described. 2 and 3 are diagrams for explaining a process of manufacturing the dye-sensitized solar cell 10. As shown in FIG. 2, first, a transparent substrate 111 made of glass or the like is prepared, and a transparent electrode 112 made of a transparent conductive layer is formed thereon, thereby preparing the transparent electrode substrate 11. Examples of the transparent conductive layer include the above-described transparent transparent conductive layers such as Pt, C, and ITO. Moreover, the conductive glass which provided the conductive layers, such as a fluorine dope tin oxide, on the surface as the transparent electrode substrate 11 can also be used.

  Next, a part of the transparent electrode 112 is removed according to the arrangement of the photoelectric conversion elements. As this method, for example, a laser scrape, a sand blaster, or the like can be used. Alternatively, a transparent mask can be formed by applying a mask patterned in advance to the transparent substrate 111 and then applying a conductive layer forming application fee.

  Next, the semiconductor layers 13-1 and 13-2 are formed on the transparent electrode 112, for example, according to the following method. First, semiconductor fine particles, a dispersant, and a solvent are mixed and dispersed using a dispersing device such as a sand mill to prepare a semiconductor fine particle dispersion, and then this dispersion is mixed and stirred with a binder, thereby containing semiconductor fine particles. Get a paste. Next, this semiconductor fine particle-containing paste is applied on the transparent electrode 112 to a thickness of, for example, about 10 to 50 μm, preferably about 15 to 20 μm. Next, after drying as necessary, it is formed by firing at a temperature of, for example, 550 ° C. or less in air. Usually, the target semiconductor layers 13-1 and 13-2 are obtained by repeating the above-described coating and baking steps. As for the film thickness of the semiconductor layers 13-1 and 13-2 after baking, 15-35 micrometers is preferable.

  The solvent preferably has a high boiling point, and for example, a mixture of alpha-terpineol, 1-p-menten-8-ol and acetylacetone can be preferably used. Moreover, as a dispersing agent, a polyester-type dispersing agent can be used preferably, for example. As the binder, one that has an increase in viscosity of the paste containing semiconductor fine particles and an effect of preventing cracking of the semiconductor layer, and evaporates or burns at 550 ° C. or less is used. For example, a cellulose-based binder or polyethylene glycol can be suitably used. The addition amount of the binder is preferably 10 to 60% by weight with respect to the semiconductor fine particles in the semiconductor fine particle-containing paste.

  Moreover, as a method of applying the semiconductor fine particle-containing paste, screen printing is preferable. In addition, flexographic printing, gravure printing, doctor blade, bar coater, roll coater, spin coater, dip coater, or the like can be used.

  Next, the redox electrode 17 is formed in the transparent electrode side current extraction part 15 of the transparent electrode 112. The redox electrode 17 is formed, for example, by applying a paste containing a redox electrode material, drying, and firing if necessary.

  The paste containing the redox electrode material is mixed with the redox electrode material, a dispersing agent, and a solvent, and dispersed using a dispersing device such as a sand mill to prepare a redox electrode material dispersion liquid. By mixing and stirring with a binder, a redox electrode material-containing paste is obtained. Next, the redox electrode material-containing paste is applied on the current extraction unit 15 to a thickness of, for example, 10 to 50 μm, preferably 15 to 20 μm. Next, after drying as necessary, it is formed, for example, by baking at a temperature of 300 to 500 ° C. in nitrogen. As for the film thickness of the oxidation reduction electrode 17 after baking, 5-30 micrometers is preferable.

  The catalyst can be supported on the redox electrode material by using a method such as making a paste after supporting the catalyst on the redox electrode material. For example, a paste can be prepared after mixing Pt ultrafine particles of 1 to 5 nm and carbon particles of 10 to 50 nm at an appropriate ratio and adsorbing Pt on the surface of the carbon particles.

  Further, the catalyst can be supported on the redox electrode material in the heating process at the time of electrode formation. For example, a Pt complex is mixed with a carbon particle-containing paste, and the Pt complex is thermally decomposed in the heating process at the time of electrode formation after the paste is applied, thereby generating Pt ultrafine particles and supporting Pt on the carbon particles. . Furthermore, the catalyst can be supported after forming the redox electrode. For example, after producing a carbon electrode with a carbon fine particle-containing paste, a Pt complex solution is applied and dried, Pt fine particles are generated by thermal decomposition, and Pt is supported on the carbon particles.

  Next, the transparent electrode substrate 11 on which the semiconductor layers 13-1 and 13-2 and the redox electrode 17 are formed is immersed in a dye solution in which a predetermined dye body is dissolved or refluxed in the dye solution. By doing so, the dye bodies are adsorbed to the semiconductor layers 13-1 and 13-2.

  At this time, the dye is also adsorbed to the oxidation-reduction electrode 17, but there is no problem in the operation of the battery. In order to avoid dye adsorption to the oxidation-reduction electrode 17, if the dye solution is circulated only through the photoelectric conversion element from the injection port after sealing, it is adsorbed only to the semiconductor layers 13-1 and 13-2. In this case, the dye is adsorbed to the counter electrodes 122; 123, which also has no problem in the operation of the battery. Alternatively, the dye solution can be dropped and adsorbed only on the semiconductor layers 13-1 and 13-2.

  On the other hand, the counter substrate 12 is formed by preparing a predetermined substrate 121 and sequentially forming conductive layers 122 and 123 on the substrate 121. The conductive layers 122 and 123 function as a counter electrode as described above.

  Next, as in the case of the transparent electrode 112, a part of the counter electrode 122; 123 of the counter electrode substrate 12 is removed according to the arrangement of the photoelectric conversion elements. Next, the redox electrode 17 is formed at the counter electrode side current extraction part 16 of the counter electrode 122; 123. As described above, the redox electrode 17 is formed by applying, drying, and firing if necessary, a paste containing a redox electrode material.

  Next, as shown in FIG. 3, the transparent electrode substrate 11 and the counter electrode substrate 12 are bonded via sealing materials (side walls) 14-1 and 14-2 so that the electrode sides face each other. At this time, the distance between the transparent electrode 12 and the counter electrode 122; 123 can be about 1 μm to 1000 μm, and preferably 10 μm to 50 μm. Moreover, the sealing materials 14-1 and 14-2 function as side walls of the photoelectric conversion elements, and serve as a support between the substrates.

  The sealing materials 14-1 and 14-2 are made of an insulating material, and can be composed of, for example, an epoxy resin, a fluorine-containing resin, an ionomer resin or the like alone or in combination. In this case, the two substrates can be joined via the sealing materials 14-1 and 14-2 by thermocompression bonding using an ionomer resin which is a thermoplastic resin.

  Next, the electrolyte 18 is injected so that the semiconductor layers 13-1 and 13-2 and the oxidation-reduction electrode 17 are embedded in the space surrounded by the transparent electrode 112 and the counter electrode 122; 123. Thus, the first photoelectric conversion element 20 including the transparent electrode 112, the counter electrode 122; 123, the semiconductor layer 13-1, and the electrolyte 18, the transparent electrode 112, the counter electrode 122; 123, and the semiconductor layer 13-2. , And the second photoelectric conversion element 30 constituted by the electrolyte 18 are formed so as to be adjacent to each other on the same substrate. Further, the first photoelectric conversion elements 20 and 30 are electrically connected in series with each other through the electrolyte 18 and the redox electrode 17 (and the redox catalyst).

  By passing through the above processes, the target dye-sensitized solar cell shown in FIG. 1 can be obtained.

  In addition, when injecting the electrolyte 18, it is preferable to provide an electrolyte injection port in advance in the transparent electrode 112 or the counter electrode 122; 123.

(Example)
A conductive glass substrate having a fluorine-doped tin oxide transparent conductive film formed thereon is prepared, and a part of the transparent conductive film is laser-treated so that each photoelectric conversion element formed on the transparent conductive film can be connected in series. The transparent electrode substrate in which the transparent conductive layer was patterned was removed by scrubbing. Titanium oxide paste was applied and fired at a predetermined location on the transparent electrode substrate to form an oxide semiconductor porous layer with a thickness of 35 μm.

  Next, in order to form a redox electrode on the transparent electrode substrate, a paste obtained by adding a Pt complex to carbon fine particles was applied and baked to obtain a redox electrode layer having a thickness of 10 μm.

  On the other hand, a conductive glass substrate provided with a fluorine-doped tin oxide conductive layer on the surface, which functions as a counter electrode substrate, was prepared, and a hole for injecting an electrolyte solution having a diameter of about 0.5 mm was formed on the substrate. Next, in order to form a redox electrode on the counter electrode substrate, a paste containing a Pt complex on carbon fine particles was pattern printed and baked to obtain a redox electrode layer having a thickness of 10 μm.

  Next, a dye solution is dropped onto the oxide semiconductor porous layer on the transparent electrode substrate to carry a Ru dye, and then both electrode substrates are thermocompression-bonded using a thermoplastic ionomer resin as a sealing material. Sealed. At this time, the redox electrodes of both electrode substrates were not in contact with each other, and the distance between them was 20 μm. The distance between the transparent electrode and the counter electrode was 40 μm.

  Next, an iodine electrolyte solution was put between the transparent electrode and the counter electrode from the electrolyte solution injection hole to form a module.

  The above process was repeated to produce a total of 10 similar modules. In each module, the four oxide semiconductor porous layers were formed adjacent to each other at a predetermined interval so that a total of four photoelectric conversion elements were electrically connected in series.

  The modules obtained as described above had an average photoelectric conversion efficiency of 8%. All the modules showed the same performance and the yield was almost 100%. Further, in the long-term stability test, there was no significant deterioration even after 1000 hours.

(Comparative example)
A conductive glass substrate having a fluorine-doped tin oxide transparent conductive film formed thereon is prepared, and a part of the transparent conductive film is laser-treated so that each photoelectric conversion element formed on the transparent conductive film can be connected in series. The transparent electrode substrate in which the transparent conductive layer was patterned was removed by scrubbing. Titanium oxide paste was applied to a predetermined location on the transparent electrode substrate and baked to form an oxide semiconductor porous layer with a thickness of 35 μm. Next, in order to form a conducting electrode, a silver paste was applied and baked to obtain a conducting electrode having a thickness of 30 μm.

  On the other hand, a conductive glass substrate provided with a fluorine-doped tin oxide conductive layer on the surface, which functions as a counter electrode substrate, was prepared, and a hole for injecting an electrolyte solution having a diameter of about 0.5 mm was formed on the substrate. Next, in order to form a conductive electrode, a silver paste was applied and baked to obtain a conductive electrode having a thickness of 30 μm.

  Next, a dye solution is dropped onto the oxide semiconductor porous layer on the transparent electrode substrate to carry a Ru dye, and then both electrode substrates are thermocompression-bonded using a thermoplastic ionomer resin as a sealing material. Sealed. At this time, the conductive electrodes of both electrode substrates were brought into contact. The distance between the transparent electrode and the counter electrode was 60 μm. Next, an iodine electrolyte solution was put only into the photoelectric conversion element portion from the electrolyte solution injection hole to form a module.

  The above process was repeated to produce a total of 10 similar modules. In each module, the four oxide semiconductor porous layers were formed adjacent to each other at a predetermined interval so that a total of four photoelectric conversion elements were electrically connected in series.

  Six of the obtained 10 modules showed a photoelectric conversion efficiency of 7 to 8% as in the examples, but the remaining four photoelectric conversion efficiencies were 1% or less. This is because a part of the conductive electrode is not in contact, and the yield was 60%. Further, in the long-term stability test, corrosion of the conductive electrode was observed in four of the six modules that showed good photoelectric conversion efficiency. In the module in which this corrosion was confirmed, the photoelectric conversion efficiency was reduced to about 3%.

  As described above, the present invention has been described in detail according to the best embodiment, but the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  For example, in the above specific example, two or four photoelectric conversion elements are connected in series to form a dye-sensitized solar cell, but the number of photoelectric conversion elements is not limited to these and is necessary. It can be set to an arbitrary number depending on. Further, the transparent electrode is composed of a single conductive layer, and the counter electrode is composed of two conductive layers 122 and 123, but the number of electrode layers constituting each electrode is not particularly limited.

  Moreover, in the said specific example, although the electrolyte which comprises each photoelectric conversion element and the electrolyte which electrically connects an adjacent photoelectric conversion element were comprised from the same electrolyte 18, it can also comprise from a different electrolyte, respectively. Furthermore, in the above specific example, two barriers 14-1 and 14-2 are provided, but either one may be used or these barriers may not be used. However, when the barrier is not used, the transparent electrode 112 and the conductive paths 122 and 123 are partially divided, and it is necessary for the current to flow as shown by an arrow in FIG.

It is a block diagram which shows an example of the dye-sensitized solar cell of this invention. It is process drawing for demonstrating the manufacturing method of the dye-sensitized solar cell of this invention. Similarly, it is process drawing for demonstrating the manufacturing method of the dye-sensitized solar cell of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dye-sensitized solar cell 11 Transparent electrode substrate 111 Transparent substrate 112 Transparent electrode 12 Counter electrode substrate 121 Substrate 122, 123 Counter electrode 13-1, 13-2 Semiconductor layer 14-1, 14-2 Sealing material 15 Transparent electrode Side current extraction unit 16 Counter electrode side current extraction unit 17 Redox electrode 18 Electrolyte 20 First photoelectric conversion element 30 Second photoelectric conversion element

Claims (5)

A plurality of photoelectric conversion elements composed of a transparent electrode, a semiconductor layer carrying a dye, a first electrolyte, and a counter electrode are formed on the same substrate, and the plurality of photoelectric conversion elements are adjacent to each other. to spacing between elements is sealed to hold the space between each adjacent photoelectric conversion elements two with a sealing material, the space in which the formed between the two sealing member , A redox electrode is provided on the transparent electrode and the counter electrode of the adjacent photoelectric conversion element, and the redox electrodes are arranged so as not to contact each other and to contact with the counter electrode or the transparent electrode existing opposite to each other. The dye-sensitized solar cell is characterized in that the plurality of photoelectric conversion elements are electrically connected to each other by further providing a second electrolyte layer.   The dye-sensitized solar cell according to claim 1, wherein at least one of the redox electrode provided on the transparent electrode and the redox electrode provided on the counter electrode is made of carbon or metal. .   The dye-sensitized solar cell according to claim 1 or 2, wherein the redox electrode is porous.   The dye-sensitized solar cell according to any one of claims 1 to 3, wherein the redox electrode is composed of C, Ni, Cr, In, Ti, Sn, and two or more kinds of these compounds. .   The dye-sensitized solar cell according to any one of claims 1 to 4, wherein a redox catalyst is supported on the redox electrode.

Images