JP2006318765A - Photoelectric conversion element, photoelectric conversion element module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectric conversion element having structure enhancing the degree of flexibility of selecting the material of an electrode. <P>SOLUTION: The photoelectric conversion element has a first support 1, a first electrode 3 and a second electrode 4 separated from each other and positioned on the main surface of the first support, a photoelectric conversion layer 5 comprising a dye-adsorbed semiconductor layer and coming in contact with the first electrode, a second support 2 arranged to face the main surface of the first support, and a carrier transport layer 6 installed between the first support and the second support. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photoelectric conversion element and a photoelectric conversion element module.

  Solar cells that can convert sunlight into electric power are attracting attention as an energy source to replace fossil fuels. Currently, some solar cells that have begun to be put into practical use include solar cells using crystalline silicon substrates and thin-film silicon solar cells. However, the former has a problem that the manufacturing cost of the silicon substrate is high, and the latter needs to use various semiconductor gases and complicated apparatuses, and the manufacturing cost is still high. For this reason, efforts have been made to reduce the cost per power generation output by increasing the efficiency of photoelectric conversion in any of the solar cells, but they have not yet solved the above problem.

  As a new type of solar cell, Patent Document 1 discloses a wet solar cell to which photoinduced electron transfer of a metal complex is applied. In this wet solar cell, a photoelectric conversion layer is formed by using a photoelectric conversion material and an electrolyte material between electrodes formed on two glass substrates. This photoelectric conversion material has an absorption spectrum in the visible light region by adsorbing a photosensitizing dye. In this solar cell, when the photoelectric conversion layer is irradiated with light, electrons are generated, and the electrons move to an electrode through an external electric circuit. The electrons that have moved to the electrode are carried by the ions in the electrolyte and return to the photoelectric conversion layer via the opposing electrode. In this way, electric energy can be extracted.

Based on this operation, Patent Document 2 discloses a dye-sensitized solar cell module in which a plurality of dye-sensitized solar cells are connected in series. Specifically, each dye-sensitized solar cell is formed by sequentially laminating a titanium oxide layer, an insulating porous layer, and a counter electrode on a glass substrate on which a transparent conductive film (electrode) patterned in a strip shape is formed. It has the structure. Moreover, both the solar cells are connected in series by disposing the conductive layer of one dye-sensitized solar cell so that the counter electrode is in contact with the adjacent dye-sensitized solar cell.
Japanese Patent No. 2664194 International Publication No. WO97 / 16838 Pamphlet

Since the solar cell has a configuration in which a photoelectric conversion layer is provided between electrodes facing each other, at least one of the facing electrodes needs to be transparent in order to irradiate the photoelectric conversion layer with light. Furthermore, since high electrical conductivity is also required to reduce IR loss, the degree of freedom in material selection is small.
This invention is made | formed in view of the situation which concerns, and provides the photoelectric conversion element which has a structure which can make the freedom degree of selection of the material of an electrode high.

Means for Solving the Problems and Effects of the Invention

  The photoelectric conversion element of the present invention comprises a first support, a first and second electrodes that are on the main surface of the first support and are not in contact with each other, and a semiconductor layer on which a dye is adsorbed. A photoelectric conversion layer in contact with the electrode, a second support disposed so as to face the main surface of the first support, and a carrier transport layer provided between the first and second supports. Features.

  According to the present invention, both the first and second electrodes are formed on the first support. Therefore, by irradiating light from the second support side, it is possible to irradiate light to the photoelectric conversion layer without using an electrode. Therefore, it is not necessary to use a highly transparent material for the first and second electrodes. For this reason, the first and second electrodes can be formed of a material having high electrical conductivity, the IR loss at these electrodes can be reduced, and the photoelectric conversion efficiency can be improved.

  The photoelectric conversion element of the present invention comprises a first support, a first and second electrodes that are on the main surface of the first support and are not in contact with each other, and a semiconductor layer on which a dye is adsorbed. A photoelectric conversion layer in contact with the electrode; a second support disposed so as to face the main surface of the first support; and a carrier transport layer provided between the first and second supports.

1. The first support and the second support The material of the first support is not particularly limited as long as it is heat-resistant to the process temperature necessary for forming the semiconductor layer and is an insulating substrate. Examples thereof include glass substrates such as soda glass, fused quartz glass, and crystalline quartz glass, heat resistant resin plates, ceramic substrates, and the like. For example, when a paste for forming a porous semiconductor containing ethyl cellulose is used, it is preferable that the paste has heat resistance of about 500 ° C., and if the paste does not contain ethyl cellulose, heat resistance of about 120 ° C. is sufficient.

  The heat resistant resin plate is made of, for example, polyester, polyacryl, polyimide, Teflon (registered trademark), polyethylene, polypropylene, PET, or the like.

  Furthermore, the first support can be used when the completed photoelectric conversion element is attached to another structure. That is, when using a support such as glass, the peripheral portion of the glass can be easily attached to another support using a metal processed part and a screw.

  The description of the first support basically applies to the second support. However, since the second support does not need to be heated and does not require heat resistance, it is possible to use more types of materials such as tempered glass and a cheaper and lighter flexible film. Moreover, when using the solvent with a possibility of volatilization for a carrier transport layer, it is preferable to use a material with low moisture permeability with respect to this solvent. Moreover, in order to improve workability | operativity at the time of producing a sealing layer, it is preferable that the 2nd support body is fixed to some extent. Therefore, for example, it is preferable to use a flexible film as the second support, place the second support on the first support, and heat-press both of them. The flexible film is made of, for example, modified polypropylene.

  In addition, it is required that at least one of the first support and the second support has light transmittance, and it is preferable that the second support has light transmittance. This is because an electrode is not formed on the second support side, so that a wider light receiving area can be secured.

2. First electrode The first electrode has a function of extracting electrons generated in the photoelectric conversion layer to an external circuit. In order to extract electrons smoothly, the first electrode is preferably formed of a material that is in ohmic contact with the photoelectric conversion layer. Therefore, the first electrode preferably has a work function smaller than that of the photoelectric conversion layer. As the material of the first electrode, for example, ITO (indium-tin composite oxide), fluorine-doped tin oxide, boron, zinc oxide doped with gallium or aluminum, titanium oxide doped with niobium, etc. Metal oxides and the like. Moreover, silver, copper, aluminum, indium, titanium, nickel, tantalum, iron, etc. are mentioned, The alloy produced combining some of these may be sufficient.

  When using a material having a strong corrosive material such as iodine for the carrier transport layer, corrosion resistance is required, and an oxide conductive material, a metal having a strong corrosion resistance or a metal constituting a dense oxide material on the surface is preferable. Specifically, ITO, fluorine-doped tin oxide, titanium, tantalum and the like can be mentioned.

  Since the part where corrosion resistance is required is only the interface between the carrier transport layer and the first electrode, a method of coating the surface of the first electrode with a material having strong corrosion resistance may be used.

  The first electrode can be formed, for example, in a stripe shape, and the width thereof may not be uniform unless it is in contact with the adjacent first electrode or second electrode. Moreover, when producing a photoelectric conversion element module, you may contact about the part which connects adjacent photoelectric conversion elements in series.

  The interval between the adjacent first electrodes is not particularly limited as long as the electrons in the photoelectric conversion layer can reach the first electrode, but is preferably within 100 μm, and more preferably within 50 μm. This is because in this case, the distance between the farthest position in the photoelectric conversion layer and the first electrode does not become too large, and electrons generated in the photoelectric conversion layer can reach the first electrode. For the same reason, the distance between the end of the photoelectric conversion layer and the first electrode located closest to the end is also preferably within 50 μm, for example. Further, the distance between adjacent first electrodes is not particularly limited as long as it can be formed without contact, but for example, the distance may be 1 μm or more.

  The thickness of the first electrode is not particularly limited. For example, when the first electrode is formed on the support, it is preferably 0.1 μm or more so that the resistance does not become too high. Moreover, since it is preferable that a photoelectric conversion layer exists on a 1st electrode for the effective utilization of a light-receiving surface, it is preferable that the film thickness of a 1st electrode is thinner than a photoelectric conversion layer.

3. Second electrode The second electrode has two functions of smoothly passing electrons to the redox species by taking in electrons from an external circuit and promoting the redox reaction. The material used for the surface of the second electrode may be any material that promotes a redox reaction in the carrier transport layer described later (has a catalytic function).

The distance between the adjacent second electrodes is not particularly limited as long as the redox species can reach the second electrode, but is preferably within 150 μm, and more preferably within 100 μm. This is because the distance of the redox species between the farthest position in the photoelectric conversion layer and the second electrode does not become too large if the distance is at this level. For the same reason, the distance between the end of the photoelectric conversion layer and the second electrode closest to the end is also preferably within, for example, 75 μm. However, this distance may be large if the mobility of the redox species in the electrolytic solution is large, and the distance is preferably small if the mobility is small.
The second electrode is formed so as not to be in contact with the first electrode. The distance between the first and second electrodes is preferably 100 μm or less, although not particularly limited as long as the redox species can reach the second electrode. This is because when the thickness is 100 μm or more, the transport resistance of the redox species increases and the performance decreases.

The second electrode may be in contact with the photoelectric conversion layer or non-contact.
When using a structure in which the second electrode is in contact with the photoelectric conversion layer, the second electrode should be formed of a material that is in Schottky contact with the photoelectric conversion layer in order to prevent electron injection from the photoelectric conversion layer to the second electrode. Is preferred. Therefore, it is preferable that the second electrode has a work function larger than that of the photoelectric conversion layer. The second electrode preferably has a work function larger than that of the first electrode.

The second electrode and the semiconductor layer may be not in contact with each other. Such a structure is, for example, that the surface of the second electrode is covered with a polymer material, and the raw material paste of the porous semiconductor layer is printed and dried thereon, and the polymer material is also oxidized and removed when firing. Can be produced. By making the coating thickness of this polymer material very thin, which is less than submicron, the distance that ions in the carrier transport layer move between the second electrode and the porous semiconductor layer is larger than that of conventional photoelectric conversion elements. It can be shortened and the photoelectric conversion efficiency can be improved.
As a material that can be used in this case, a material having a decomposition temperature higher than that of a polymer material generally contained in a titanium oxide paste used for forming a porous semiconductor layer can be considered. Specifically, for example, nitrocellulose can be used as the polymer material in the titanium oxide paste, and ethylcellulose can be used as the polymer material on the surface of the second electrode.

  The firing condition is that the polymer material is preferentially decomposed by holding it at the decomposition temperature of the polymer material in the titanium oxide paste for several tens of minutes, and then the decomposition temperature of the polymer material on the surface of the second electrode By decomposing the polymer material by firing at a predetermined firing temperature (for example, 500 ° C.), the second electrode and the porous semiconductor layer can be brought into a non-contact structure.

  The second electrode may be formed of, for example, platinum, palladium, an alloy containing them, or carbon (carbon black, graphite, glass carbon, amorphous carbon, hard carbon, soft carbon, carbon whisker, carbon nanotube, fullerene) or the like. it can.

The second electrode may be formed of a single material, and may be composed of a conductive layer and a coating layer that covers the conductive layer. In this case, since the conductive layer does not need to have a catalytic function, the degree of freedom in material selection is high, and in order to reduce the manufacturing cost, an inexpensive material such as copper is used or IR loss when electrons are taken from an external circuit is used. In order to reduce the above, a material having high conductivity can be used. In addition, since the conductive layer is covered with the coating layer, the influence of corrosion due to the redox species contained in the carrier transport layer is small, and also in this respect, the degree of freedom in material selection is high. Note that the conductive layer is also preferably formed of a material resistant to corrosion.
In order to reduce the number of manufacturing steps, the same material may be used for the conductive layer and the first electrode, and both may be formed in the same step. As a specific production method, for example, a conductive layer and a first electrode are produced using a known method, a coating film is formed only on the conductive layer with a material that promotes a redox reaction, and a second electrode is formed. Make it.

  The surface area of the second electrode may be 5% or more of the projected area of the semiconductor layer. Moreover, the surface area of a 2nd electrode can be increased and FF can be improved by making a 2nd electrode into stripe shape with a high aspect ratio, or forming an unevenness | corrugation in the surface of a 2nd electrode. In order to increase the surface area of the second electrode, a method of treating the surface of the second electrode with chloroplatinic acid may be used. The second electrode can be formed in a stripe shape, for example, and the width thereof may be approximately the same as that of the first electrode.

4). Photoelectric conversion layer The photoelectric conversion layer is composed of a semiconductor layer to which a dye is adsorbed.
4-1. Semiconductor Layer The semiconductor layer is preferably porous, and various forms such as a particle form and a film form can be used, but a film form is preferred. As a material constituting the semiconductor layer, known semiconductors such as titanium oxide, zinc oxide, tungsten oxide, barium titanate, strontium titanate, and cadmium sulfide can be used alone or in combination of two or more. Among these, titanium oxide is preferable in terms of conversion efficiency, stability, and safety.

  Various known methods can be used as a method for forming a film-like semiconductor layer on a substrate. Specifically, a paste containing semiconductor particles is applied on a substrate such as a screen printing method or an ink jet method, and then fired, or a film is formed on the substrate by a CVD method or a MOCVD method using a desired source gas. And a method using a raw material solid, a PVD method using a raw material solid, a vapor deposition method, a sputtering method or a sol-gel method, an electrochemical oxidation-reduction reaction, and the like. Among these, the screen printing method using a paste is preferable from the viewpoint of thickening and manufacturing cost.

  Although the film thickness of a semiconductor layer is not specifically limited, About 5-50 micrometers is preferable from a viewpoint of conversion efficiency.

In order to improve the conversion efficiency, it is necessary to adsorb more dye, which will be described later, to the semiconductor layer. For this reason, a semiconductor layer with a large specific surface area is preferable, and about 10-200 m < ² > / g is preferable. In addition, the specific surface area shown in this specification is a value measured by the BET adsorption method.

  As the above-mentioned semiconductor particles, single or compound semiconductor particles having an appropriate average particle diameter among commercially available particles, for example, an average particle diameter of about 1 nm to 500 nm can be mentioned. Moreover, when using titanium oxide as a semiconductor particle, it can produce with the following method.

  125 ml of titanium isopropoxide (manufactured by Kishida Chemical Co., Ltd.) was dropped into 750 mL of a 0.1M aqueous nitric acid solution (manufactured by Kishida Chemical Co., Ltd.), hydrolyzed, and heated at 80 ° C. for 8 hours to prepare a sol solution. Do. Thereafter, particles are grown in a titanium autoclave at 230 ° C. for 11 hours, and ultrasonic dispersion is performed for 30 minutes, thereby preparing a colloidal solution containing titanium oxide particles having an average primary particle size of 15 nm. By repeating the procedure of adding 200 ml of ethanol to the solution and centrifuging at 5000 rpm, the pH of the solution can be neutralized and titanium oxide particles can be produced. In addition, the average particle diameter in this specification is a value measured by SEM observation.

  Solvents used for suspending these semiconductor particles to prepare a paste include glyme solvents such as ethylene glycol monomethyl ether, alcohol solvents such as isopropyl alcohol, mixed solvents such as isopropyl alcohol / toluene, water, and the like. Can be mentioned. Specifically, a paste can be produced by the steps shown below.

  After washing the titanium oxide particles produced by the above-mentioned process, ethyl cellulose (manufactured by Kishida Chemical Co., Ltd.) and terpineol (manufactured by Kishida Chemical Co., Ltd.) dissolved in absolute ethanol are added, and the titanium oxide particles are stirred by stirring. Disperse. Thereafter, ethanol was evaporated at 50 ° C. under a vacuum of 40 mbar, so that the final composition was titanium oxide solid concentration 20 wt%, ethyl cellulose 10 wt%, and terpineol 64 wt%. Is made.

  The above-described drying and firing of the semiconductor layer is performed by appropriately adjusting conditions such as temperature, time, atmosphere, and the like according to the type of substrate and semiconductor particles used. Such conditions include, for example, about 10 seconds to 12 hours in the range of about 50 to 800 ° C. in the air or in an inert gas atmosphere. This drying and baking can be performed once at a single temperature or twice or more by changing the temperature.

4-2. Dyes Adsorbed on the semiconductor layer and functioning as a photosensitizer include those having absorption in various visible light regions and / or infrared light regions. Furthermore, in order to strongly adsorb the dye to the semiconductor layer, the carboxylic acid group, carboxylic anhydride group, alkoxy group, hydroxyl group, hydroxyalkyl group, sulfonic acid group, ester group, mercapto group, phosphonyl group in the dye molecule. Those having an interlocking group such as Among these, a carboxylic acid group and a carboxylic anhydride group are more preferable. The interlock group provides an electrical coupling that facilitates electron transfer between the excited dye and the conduction band of the semiconductor layer.

  Examples of these dyes containing an interlock group include ruthenium bipyridine dyes, azo dyes, quinone dyes, quinone imine dyes, quinacridone dyes, squarylium dyes, cyanine dyes, merocyanine dyes, and triphenylmethane dyes. Xanthene dyes, porphyrin dyes, phthalocyanine dyes, berylene dyes, indigo dyes, naphthalocyanine dyes, and the like.

  Examples of the method for adsorbing the dye to the semiconductor layer include a method of immersing the semiconductor layer formed on the support in a solution in which the dye is dissolved (dye adsorption solution).

  The solvent for dissolving the dye may be any solvent that can dissolve the dye. Specifically, alcohols such as ethanol, ketones such as acetone, ethers such as diethyl ether and tetrahydrofuran, and nitrogen compounds such as acetonitrile. , Halogenated aliphatic hydrocarbons such as chloroform, aliphatic hydrocarbons such as hexane, aromatic hydrocarbons such as benzene, esters such as ethyl acetate, water, and the like. Two or more of these solvents can be used in combination.

The concentration of the dye in the solution can be appropriately adjusted depending on the kind of the dye and the solvent to be used, but is preferably as high as possible in order to improve the adsorption function, for example, 1 × 10 ⁻⁵ mol / liter. The above is preferable.

5. Carrier transport layer The carrier transport layer is provided between the first and second supports. Such a carrier transport layer, for example, by injecting a carrier transport liquid between the first and second supports, the carrier transport liquid is introduced into the gaps in the photoelectric conversion layer and the gaps between the second support and the photoelectric conversion layer. It can be formed by filling. The carrier transport liquid is made of a material capable of transporting ions, and preferably made of an ionic conductor such as an electrolytic solution or a polymer electrolyte. The ionic conductor is composed of, for example, a redox species and a solvent capable of dissolving it. Specific examples of the redox species include iron-based and cobalt-based metals, and halogens such as chlorine, bromine, and iodine, and iodine is generally used. The carrier transport layer may be gelled or quasi-solidified by various methods.

  When iodine is used as a redox species, it is not particularly limited as long as it can generally be used for batteries, etc. Among them, combinations with metal iodides such as lithium iodide, sodium iodide, potassium iodide, calcium iodide, etc. Is most preferred. Further, an imidazole salt such as dimethylpropylimidazole iodide may be mixed.

  Examples of the solvent for dissolving the redox species include carbonate compounds such as propylene carbonate, nitrile compounds such as acetonitrile, alcohols such as ethanol, water, aprotic polar substances, and the like. Carbonate compounds and nitrile compounds are preferred. Two or more of these solvents can be used in combination. On the other hand, when the volatilization of the solvent becomes a problem, a molten salt may be used instead of the solvent.

  The electrolyte concentration is selected depending on various electrolytes, but is preferably in the range of 0.01 to 1.5 mol / liter.

  Even when the second electrode and the photoelectric conversion layer are in contact, direct electron transfer from the photoelectric conversion layer to the second electrode does not substantially occur, and the electron transfer is performed via the carrier transport layer. This has been demonstrated in experiments. Accordingly, even in this case, a carrier transport layer is necessary.

6). Sealing layer In order to prevent volatilization of the solvent used in the carrier transport layer and intrusion of water or the like, it is preferable to form a sealing layer that seals between the first and second supports. In addition, when a resin-based material is used for the sealing layer, (1) it can absorb an impact when an object falls on the substrate or a force is applied, and (2) the glass used as a support when used over a long period of time. There are advantages such as being able to absorb deflection and the like.

  The sealing layer is preferably formed using a material such as a silicone resin, an epoxy resin, a polyisobutylene resin, a hot melt resin, or a glass frit. In particular, when a nitrile solvent or a carbonate solvent is used as a solvent for the carrier transport liquid, a silicone resin, a hot melt resin (for example, an ionomer resin), a polyisobutylene resin, or a glass frit is preferable. Two or more kinds of resins can be used in two or more layers.

  The pattern of the sealing layer can be formed by a dispenser when silicone resin, epoxy resin, glass frit, or the like is used. Moreover, when using hot-melt resin, the sealing pattern can be formed by making the hole patterned in the sheet-like hot-melt resin.

  The film thickness of the sealing layer is preferably such that the photoelectric conversion layer and the second support are in contact with each other. When the film thickness of the sealing layer is thin, a gap formed between the support and the photoelectric conversion layer is increased due to the support being bent, so that only the carrier transport layer is increased. Even when the sealing layer is thick, the gap between the support and the photoelectric conversion layer becomes large, so that only the carrier transport layer increases. In order to prevent a part of incident light from being absorbed by the carrier transport layer before reaching the photoelectric conversion layer, such a gap is preferably small.

  In addition, this invention also provides the photoelectric conversion element module characterized by connecting at least 2 of the said photoelectric conversion elements in series. The module may further include an insulating layer that separates the photoelectric conversion layer and the carrier transport layer of adjacent photoelectric conversion elements.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited by these Examples and a comparative example.

  In Example 1, a photoelectric conversion element (dye-sensitized solar cell) as shown in FIG. 1 (cross-sectional view) was produced. The manufacturing process is shown below.

1. Production of first and second electrodes on a substrate Using a vacuum deposition method on a glass substrate 1, a first electrode 3 made of titanium and a second electrode 4 made of platinum are each 10 μm wide and adjacent second electrodes. The gap between the right end of the first electrode and the left end of the first electrode (or the left end of the second electrode and the right end of the first electrode) was 10 μm, the film thickness was 5 μm, and 4 cm square. Thereafter, an electrolyte injection port (not shown) was opened in the substrate 1.

2. Production of photoelectric conversion layer Next, a porous semiconductor layer was produced, and a photoelectric conversion layer 5 was produced by adsorbing a dye thereto. Details will be described below.

2-1. Production of porous semiconductor layer The first electrode 3 and the second electrode 4 are formed by screen printing of a commercially available titanium oxide paste (manufactured by Solaronix, trade name Ti-Nanoxide D / SP, average particle size 13 nm). It apply | coated on the glass substrate 1 at 2 square cm. Next, it was baked at 500 ° C. for 20 minutes. A porous semiconductor layer made of a titanium oxide film having a thickness of 15 μm was obtained.

2-2. Adsorption of dye Sensitizing dye N719 represented by chemical formula (1) (Ru535bisTBA manufactured by Solaronix) is ethanol (manufactured by Aldrich Chemical Company (hereinafter, “manufactured by ACC”) in a concentration of 3 × 10 ⁻⁴ mol / liter) To prepare a solution.
Next, the glass substrate on which the porous semiconductor layer was formed was held in this solution for 120 hours to adsorb the sensitizing dye to the porous semiconductor layer. Thereafter, the porous semiconductor layer was washed and dried with ethanol (manufactured by ACC) to produce a photoelectric conversion layer 5.

3. Preparation of Redox Electrolyte Solution The redox electrolyte solution used to form the carrier transport layer 6 is acetonitrile (manufactured by ACC), 0.1 mol / liter lithium iodide (manufactured by ACC), and a concentration of 0.8. Prepared by dissolving 01 mol / liter iodine (manufactured by ACC), 0.5 mol / liter TBP (manufactured by ACC), and 0.6 mol / liter dimethylpropylimidazole iodide (DMPII, manufactured by Shikoku Kasei). did.

4). Production of Carrier Transport Layer On the photoelectric conversion layer 5 obtained above, the second support 2 made of a cover glass is placed, and in this state, a UV curable resin (manufactured by Three Bond Co., Ltd .: product name 31x-088: 20 μm) is placed on the outer periphery. Glass beads with spacers) were applied, and immediately irradiated with UV light to form the sealing layer 7. Thereafter, the carrier transport layer 6 was formed by injecting the redox electrolyte from the electrolyte inlet and closing the electrolyte inlet. Finally, a lead wire was attached to each electrode to produce a solar cell.

  In Example 2, a photoelectric conversion element as shown in FIG. 2 (cross-sectional view) was manufactured. In this example, the second support 2 and the photoelectric conversion layer 5 were brought into contact with each other, except that a spacer not mixed in the UV curable resin (manufactured by Three Bond: product name 31x-088) was used. Fabrication was performed according to Example 1.

(Comparative Example 1)
As shown in FIG. 3 (cross-sectional view), a glass plate (manufactured by Nippon Sheet Glass Co., Ltd.), which is a transparent substrate on which a SnO ₂ film is formed, is used as the first support 1 and the first electrode 3. 2 and the second electrode 4 on the same substrate as the first support 1 Pt paste (Solaronix, HYPERLINK "http://www.solaronix.com/products/Chemicals/Pt-catalyst%20TSP.htm" Pt -Catalyst T / SP) was printed and fired at 400 degrees for 30 minutes, except that a platinum film having platinum particles with a particle size of several tens to several hundreds of nanometers attached to the substrate was used. A solar cell was produced in the same manner.

(Summary of Examples 1 and 2 and Comparative Example 1)
The solar cells obtained in Examples 1 and 2 and Comparative Example 1 were irradiated with light (AM1.5 solar simulator) having an intensity of 1 kW / m ² from the counter electrode side, and the photoelectric conversion efficiency was measured. The measurement results are shown in Table 1.

In Examples 1 and 2, the conversion efficiency is higher than that in Comparative Example 1. The reason is considered that in these examples, the first and second electrodes 3 and 4 are made of metal, so that the IR loss due to the resistance can be reduced and the FF can be improved. .
In the second embodiment, the conversion efficiency is higher than that in the first embodiment. The reason is that in Example 2, the second support 2 and the porous semiconductor layer 5 are in contact with each other, so that the light incident from the second support 2 side passes before reaching the porous semiconductor layer 5. This is presumably because the distance of the transport layer 6 was shortened and the amount of light absorption in the carrier transport layer 6 was reduced.

An integrated photoelectric conversion element module in which six unit cells are connected in series was manufactured. The manufacturing process will be described with reference to FIGS. 4A to 4D (plan view).
First, as shown in FIG. 4A, a first electrode 3 made of a titanium film having a width of 8 μm, a length of 14 mm, and a thickness of 5 μm was formed on a first support 1 made of a glass plate of 64 mm × 60 mm. . The distance a between the first electrodes adjacent to each other in the vertical and horizontal directions in FIG. 4A was 10 μm. The first electrode was formed in the central part 62 mm × 52 mm of the first support 1. As a forming method, a pattern was formed using a method using a known photomask and formed using electron beam evaporation.
Next, using the same method, the second electrode 4 made of a platinum film having a width of 12 μm, a length of 7.2 mm, and a thickness of 2 μm so as to cover half of the first electrode 3 as shown in FIG. Formed.
A region 11 surrounded by an alternate long and short dash line in FIG. 4A becomes a unit cell in a later process. The module of this embodiment includes six unit cells. Further, the same number of electrolyte inlets (not shown) as the unit cells were opened.

  Next, on the glass substrate on which the first electrode 3 and the second electrode 4 are formed, the shape as shown in FIG. 4B (A = 9.5 mm, B = 5 mm, A porous semiconductor layer was formed with an interval of 3 mm. A photoelectric conversion layer 5 was produced by adsorbing a dye to the porous semiconductor layer in the same manner as in Example 1. The size of the photoelectric conversion layer 5 is 5 mm wide × 50 mm long × 20 μm thick.

  Next, as shown in FIG. 4C, a UV curable resin (manufactured by Three Bond: product name 31x-088) was applied with a width of 2 mm to form an insulating layer 8.

  Next, as shown in FIG.4 (d), the 2nd support body 2 which consists of a flexible film was crimped | bonded, and UV irradiation was performed only to the part which apply | coated UV cured resin. Then, the 1st and 2nd support bodies 1 and 2 were bonded together by performing thermocompression bonding. Next, the periphery was sealed with a UV curable resin as a sealing layer (not shown).

  Next, an electrolytic solution is prepared according to Example 1, the electrolytic solution is injected from the electrolytic solution injection port by a capillary effect, and the electrolytic solution injection port is closed to form a carrier transport layer, and a photoelectric conversion element The module was made.

The obtained photoelectric conversion element was irradiated with light having an intensity of 1 kW / m ² (AM1.5 solar simulator), and the photoelectric conversion efficiency was measured.

  As a result of the measurement, the short-circuit current was 32.4 mA, the open-circuit voltage was 4.1 V, FF = 0.6, and the conversion efficiency was 5.3%. The open circuit voltage is about the same as the sum of the unit cells, and it can be seen that the photoelectric conversion elements are connected in series. Furthermore, when 20 similar modules were produced, Voc was between 4.0V and 4.2V in all cases. From this result, it is considered that the difference between modules is not large. Therefore, it can be seen that the photoelectric conversion element module of the present invention is less prone to failure due to contact failure and has a high yield.

It is sectional drawing of the photoelectric conversion element of Example 1 of this invention. It is sectional drawing of the photoelectric conversion element of Example 2 of this invention. It is sectional drawing of the photoelectric conversion element module of the comparative example 1 of this invention. It is a top view which shows the manufacturing process of the photoelectric conversion element module of Example 3 of this invention.

Explanation of symbols

1: First support 2: Second support 3: First electrode 4: Second electrode 5: Photoelectric conversion layer 6: Carrier transport layer 7: Sealing layer 8: Insulating layer

Claims (9)

A first support;
First and second electrodes on the major surface of the first support and in non-contact with each other;
A photoelectric conversion layer made of a semiconductor layer adsorbed with a dye and in contact with the first electrode;
A second support disposed to face the main surface of the first support;
A photoelectric conversion element comprising a carrier transport layer provided between the first and second supports. The device according to claim 1, wherein the semiconductor layer is porous. The element according to claim 1, wherein at least one of the first and second supports has light transmittance. The element according to claim 1, wherein at least one of the first electrode and the second electrode has a stripe shape. The element according to claim 1, wherein the second electrode includes a conductive layer and a coating layer covering the conductive layer. The element according to claim 5, wherein the conductive layer is made of the same material as the first electrode. The device according to claim 1, wherein the photoelectric conversion layer is in contact with the second support. 8. A photoelectric conversion element module comprising at least two of the photoelectric conversion elements according to claim 1 connected in series. The module of Claim 8 further provided with the insulating layer which isolate | separates the photoelectric converting layer and carrier transport layer of an adjacent photoelectric conversion element.