TW201606827A - Photoelectric conversion layer and photoelectric conversion element provided with same - Google Patents

Abstract

A multilayer photoelectric conversion body, wherein a plurality of photoelectric conversion layers having different absorption wavelengths are laminated, is formed by sequentially coating a conductive substrate with a plurality of coating compositions, each of which contains a semiconductor (for example, titanium oxide particles) and an ionic polymer (for example, a fluorine-based resin having a sulfo group), without sintering the semiconductor, while having the coating compositions respectively contain a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths. This photoelectric conversion element is capable of efficient photoelectric conversion by means of a simple structure.

Description

Photoelectric conversion layer and photoelectric conversion element having the same

The present invention relates to a photoelectric conversion layer in a laminated form and a photoelectric conversion element (a solar cell (especially a dye-sensitized solar cell) or the like) including the photoelectric conversion layer.

Solar cells are being paid attention to as a green energy source with a small environmental burden, and solar cells using ruthenium (crystal ruthenium, etc.) are being widely used. However, since high-purity hydrazine is used, power generation cost is high, and conversion efficiency for weak light such as indoors is small.

As a solar cell that can be manufactured at low cost, a dye-sensitized solar cell is attracting attention. The dye-sensitized solar cell is formed by adsorbing a sensitizing dye to a metal oxide semiconductor (titanium oxide or the like) to form a photoelectrode.

The photoelectric conversion system of the dye-sensitized solar cells is generated at the contact interface between the metal oxide semiconductor and the sensitizing dye. Therefore, in order to improve the conversion efficiency, the electrode uses a metal oxide semiconductor having a large surface area (for example, a nano-scale metal). The oxide semiconductor) increases the effective area with respect to the apparent area. However, the metal oxide nanoparticles are peeled off from the substrate even if they are simply applied to the substrate, and have no function as an electrode, and the electric resistance between the particles is large. Therefore, after the metal oxide nanoparticles are coated, the metal oxide is sintered by heat treatment at a high temperature (about 500 ° C). As the nanoparticle, the sintered layer is immersed in a solution containing a dye to adsorb the dye to form a photoelectric conversion layer, and thermal decomposition of the dye must be avoided. These methods are complex methods involving a sintering process and also a factor in increasing manufacturing costs. Further, since the substrate needs to be exposed to a high temperature during the sintering process, the substrate is limited to an inorganic material such as glass, and a flexible dye-sensitized solar cell using a plastic substrate cannot be produced. Further, since it is limited by the absorption wavelength range of the dye, it cannot be absorbed to a long wavelength range with a single dye efficiency, so the utilization efficiency of incident light is low and the photoelectric conversion efficiency is low.

In order to avoid thermal decomposition of the dye and to effectively use the incident In the case of photoelectric conversion, a tandem photoelectric conversion element using a plurality of dyes has been proposed. Japanese Patent Publication No. 2008-34258 (Patent Document 1) discloses that a first photoelectric conversion element having a first dye adsorbed on a first photoelectrode of a first porous semiconductor and a second dye adsorbed on a second porous layer are provided. The second photoelectric conversion element of the second photoelectrode of the semiconductor is laminated in the intersecting direction with respect to the incident direction of the incident light, and the tandem dye-sensitized photoelectric system in which the first counter electrode and the second transparent conductive layer are connected in series Conversion component. In this document, a titanium oxide coating film is also fired to form a first porous semiconductor and a second porous semiconductor, and the first dye and the second dye are separately adsorbed. Further, although this document also shows a single-layer photoelectrode in which a plurality of dyes are mixed and adsorbed, or a multilayer photoelectrode in which a plurality of dyes are adsorbed in a range, the details are not described.

Japanese Patent Laid-Open Publication No. 2012-74365 (Patent Document 2) A first photovoltaic cell (PV cell) having a cathode and an anode interposed between the first dye layer and a second PV layer with a second dye layer interposed therebetween to provide a cathode and an anode A cell type dye-sensitized solar cell (DSC) for bonding a first PV cell and a second PV cell to a first transparent conductive adhesive layer in which a first PV cell and a second PV cell are connected in series is used.

These documents are based on the individual production of the first photoelectric conversion battery and Since the first photoelectric conversion battery and the first and second photoelectric conversion cells are stacked, the incident light can be efficiently photoelectrically converted. However, each of the photoelectric conversion cells is provided with a transparent support having a transparent conductive layer, a photoelectrode layer formed on the transparent conductive layer, a counter electrode facing the photoelectrode layer, and being filled between the photoelectrode layer and the counter electrode The electrolyte. Moreover, it is necessary to laminate the two photoelectric conversion cells while electrically connecting two photoelectric conversion cells. Therefore, the structure of the tandem type dye-sensitized solar cell is complicated. It is also necessary to additionally use at least one high-priced conductive transparent substrate to cause high cost. Further, the central portion (light-transmitting portion) of the photoelectric conversion battery absorbs or scatters incident light due to the electrode substrate and the electrolyte sandwiched between the pair of photoelectrode layers and the counter electrode, so that the loss of light absorption is not greatly improved. Photoelectric conversion efficiency.

There is also a porous layer which is also known for the sintered titanium oxide. The two dyes were diffused into a two-layered (dye bi-layer). However, this method not only requires a sintering operation and a diffusion operation of the dye, but also two kinds of dyes are mixed in the boundary range and the photoelectric conversion layer cannot be formed efficiently.

International Publication WO 2014/017536 (Patent Document 3) describes A composition for a photoelectric conversion layer containing 0.1 to 30 parts by weight of the ionic polymer in a ratio of 0.1 to 30 parts by weight based on 1 part by weight of the semiconductor, and a semiconductor and an ionic polymer and a dye are used to form a photovoltaic. Conversion layer. This document also describes that it is possible to target a conductive substrate. The photoelectric conversion layer is formed with high density. However, the photoelectric conversion efficiency of the photoelectric conversion layer incident light is still insufficient.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2008-34258 ([0019] [0020] [0022] [0078] to [0081] Figs. 1 to 3)

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2012-74365 (Scope of Patent Application)

[Patent Document 3] WO2014/017536 (Requests 14 and 17, [0091])

Therefore, an object of the present invention is to provide a photoelectric conversion layer or a photoelectric conversion body (photoelectrode layer) which can efficiently photoelectrically convert incident light and a photoelectric conversion element having the photoelectric conversion layer (dye sensitized sun) Battery, etc.).

Another object of the present invention is to provide a photoelectric conversion layer (or photoelectric conversion body) having a different absorption wavelength range and high photoelectric conversion efficiency, and a photoelectric conversion element including the photoelectric conversion layer.

Still another object of the present invention is to provide a photoelectric conversion layer (or photoelectric conversion body) capable of maintaining high photoelectric conversion characteristics even after being aged without being sintered, and having high adhesion to a substrate, and having the same Photoelectric conversion element of the photoelectric conversion layer.

Another object of the present invention is to provide a photoelectric conversion layer (or photoelectrode layer) which is advantageous for forming a dye-sensitized solar cell and A photoelectric conversion element of the photoelectric conversion layer.

Still another object of the present invention is to provide a benefit A coating composition for forming the aforementioned photoelectric conversion layer (or photoelectric conversion body) and a method capable of forming the aforementioned photoelectric conversion layer (or photoelectric conversion body) simply and efficiently.

In order to solve the above problems, the inventors of the present invention have found that semiconductors (such as titanium oxide), ionic binders (for example, ionic polymers such as strongly acidic ion exchange resins), and dyes (sensitizing materials) are included. In the plurality of coating compositions (coating agents or inks), the individual coating compositions contain a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths, and a plurality of coating compositions are sequentially applied to the conductive substrate. The laminated photoelectric conversion body is formed, and the incident light can be efficiently photoelectrically converted to complete the present invention.

That is, the laminated photoelectric converter (laminate) of the present invention has a laminated structure including a photoelectric conversion layer containing a semiconductor, an ionic binder, and a dye, and the multilayer photoelectric conversion system has a multilayer photoelectric conversion layer (dye-sensitized photoelectric conversion layer) ) formed by layers. Then, the dyes contained in each of the photoelectric conversion layers have different absorption wavelength ranges or absorption peak wavelengths. That is, a multilayer photoelectric conversion layer (for example, an adjacent photoelectric conversion layer) contains dyes having mutually different absorption wavelength ranges or absorption peak wavelengths. The laminated photoelectric converter of the present invention can also be referred to as, for example, an adjacent photoelectric conversion layer comprising a laminated photoelectric conversion layer that absorbs dyes having different peak wavelengths or absorption wavelength ranges, and a laminated photoelectric conversion layer system including two kinds of dyes will contain A photoelectric conversion layer of 1 dye and a photoelectric conversion layer containing the second dye. also The photoelectric conversion layer and the laminated photoelectric converter are generally formed on a conductive substrate.

In the laminated photoelectric converter, the photoelectric on the incident side (light receiving side) The dye contained in the conversion layer may have an absorption peak wavelength in a shorter wavelength range of the absorption peak wavelength of the dye contained in the photoelectric conversion layer on the more penetrating side. For example, a photoelectric conversion layer (dye-sensitized photoelectric conversion layer) containing a dye capable of absorbing a short wavelength range (for example, a short wavelength range in the visible light range) is formed on the light-receiving side, and an opposite side (penetrating side) on the light-receiving side may be formed. A photoelectric conversion layer (dye-sensitized photoelectric conversion layer) containing a dye capable of absorbing a long wavelength range such as a long wavelength range of the visible light range.

In addition, unsintered semiconductor and multilayer photoelectric conversion The layer may be formed, and the total thickness of the multilayer photoelectric conversion layer may be about 0.1 to 100 μm, and the ratio of the thickness Tr of the photoelectric conversion layer on the light receiving side to the thickness Tt of the photoelectric conversion layer on the penetration side may also be Tr/Tt=10/ 90~80/20 (for example, 30/70~80/20).

The photoelectric conversion layer on the light receiving side is contained at 300 to 650 nm ( For example, 300 to 600 nm) of the first dye having an absorption peak wavelength, and the photoelectric conversion layer of the opposite side (penetrating side) of the light receiving side may also contain a second dye having an absorption peak wavelength of 550 to 800 nm (for example, 600 to 800 nm). Further, although the absorption peak wavelengths of the plurality of dyes (for example, the absorption peak wavelengths of the first dye and the second dye) are similar, the absorption peak wavelength of the first dye is generally shorter than the absorption peak wavelength of the second dye by 10 nm or shorter. The absorption peak wavelengths of the plurality of dyes are, for example, about 10 to 200 nm (e.g., 20 to 200 nm, preferably 30 to 150 nm).

In the aforementioned photoelectric conversion layer, the semiconductor may also comprise an oxygen selected from the group consisting of oxygen Titanium nanoparticles, zinc oxide nanoparticles, tin oxide nanoparticles In the case of one less, the ionic polymer may also contain a fluorine-containing resin having a sulfo group. Further, the ratio of the ionic polymer may be from about 1 to 100 parts by weight (for example, from 5 to 50 parts by weight) per 100 parts by weight of the semiconductor.

The invention comprises a semiconductor and an ionic polymer and a dye And a combination of a coating composition (or ink) for forming a multilayer photoelectric conversion layer on a conductive substrate, and a plurality of coating compositions each containing a dye having mutually different absorption wavelength ranges or absorption peak wavelengths a combination of compositions.

Further, the present invention also includes the manufacture of the above-mentioned laminated photoelectric converter In the method, a plurality of coating compositions (or inks) containing a semiconductor, an ionic polymer, and a dye are applied onto a conductive substrate to form a photoelectric conversion layer (generally, sintering is not performed to form a photoelectric conversion layer). The absorption wavelength range or absorption peak wavelength of the dye contained in each coating agent is different from each other. That is, the individual coating compositions (or inks) contain a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths (or coating compositions for modulating dyes having different absorption wavelength ranges or absorption peak wavelengths). Then, a plurality of coating compositions (or inks) are applied and laminated on the conductive substrate in this order, and the laminated photoelectric conversion body is formed without sintering.

Furthermore, the present invention also includes the above laminated photoelectric converter (Laminated body) photoelectric conversion element. The photoelectric conversion element may further include the laminated photoelectric converter formed on the conductive substrate as an electrode (photoelectrode), a counter electrode (the other electrode) disposed to face the electrode, and a seal between the electrodes. The electrolyte phase (or electrolyte layer), the photoelectric conversion element can also form a dye-sensitized solar cell.

The present invention also encompasses the formation of electrical conductivity as an electrode A method of manufacturing a photoelectric conversion element on a substrate, a counter electrode disposed opposite to the electrode, and a photoelectric conversion element sealed with an electrolyte phase (or an electrolyte layer) between the electrodes. The method comprises the steps of sequentially coating and laminating a plurality of coating compositions comprising a semiconductor and an ionic polymer and a dye on a conductive substrate, and forming a laminated photoelectric conversion body of the multilayered photoelectric conversion layer without sintering; The absorption wavelength range or the absorption peak wavelength of the dye contained in each of the above coating agents is different from each other. That is, the method includes the steps of coating and laminating a plurality of coating compositions containing the dyes in a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths, and sequentially laminating the coating composition on the conductive substrate, and not performing sintering. A step of forming a laminated photoelectric conversion body of a multilayered photoelectric conversion layer.

The present invention is capable of forming a photoelectric conversion layer of a laminated structure, and can efficiently photoelectrically convert incident light with a simple structure. Further, the photoelectric conversion efficiency can be greatly improved by imparting different absorption wavelength ranges to the photoelectric conversion layer of the laminated structure. Further, it is possible to form a photoelectric conversion layer having a laminated structure easily and efficiently by coating, and it is excellent in durability even if sintering is not performed, and high photoelectric conversion characteristics can be maintained over a long period of time, and high adhesion to the substrate can be formed at the same time. Stoic laminated photoelectric converter. Therefore, it is advantageous to form a dye-sensitized solar cell.

Fig. 1 is a graph showing the output characteristics of the dye-sensitized solar cell obtained in the examples.

The present invention uses different types of dyes (absorbed waves) A plurality of coating compositions having a long range or a dye that absorbs mutually different peak wavelengths. Each of the coating compositions contains a semiconductor, an ionic binder, and a dye (sensitizing dye), and has film forming properties, and can be adhered to the conductive substrate to form a photoelectric conversion layer.

(semiconductor)

The semiconductor system can be roughly classified into an inorganic semiconductor or an organic semiconductor, and an inorganic semiconductor can be suitably used. As the inorganic semiconductor, a metal monomer, a metal compound (metal oxide, metal sulfide, metal nitride, or the like) or the like can be exemplified. Further, in many cases, semiconductors are light semiconductors that absorb light and generate electromotive force.

The constituent elements of the inorganic semiconductor can be selected, for example, from Group 2 metals (Ca, Sr, etc.), Group 3 metals (Sc, Y, La, etc.), Group 4 metals (Ti, Zr, Hf, etc.), Group 5 metals (V, Nb, Ta, etc.), Group 6 metals (Cr, Mo, W, etc.), Group 7 metals (Mn, etc.), Group 8 metals (Fe, etc.), Group 9 metals (Co, etc.) ), Group 10 metal (Ni, etc.), Group 11 metal (Cu, etc.), Group 12 metal (Zn, Cd, etc.), Group 13 metal (Al, Ga, In, Tl, etc.), Group 14 metal (Ge, Sn, etc.), Group 15 metals (As, Sb, Bi, etc.), Group 16 elements (Te, etc.), and the like. The semiconductor may also contain these elements alone or in combination of two or more, for example, an alloy, and the metal oxide may also be a composite oxide. The semiconductor may also contain the above metals and other metals (alkali metals, etc.).

In the specific semiconductor, examples of the metal oxide include transition metal oxides (for example, metal oxides of Group 3 of the periodic table (such as cerium oxide and cerium oxide) and metal oxides of Group 4 (titanium oxide and zirconia, Calcium titanate, barium titanate, barium titanate, etc.), Group 5 metal oxides (vanadium oxide, cerium oxide, cerium oxide (such as cerium oxide), etc.), Group 6 metal oxides (chromium oxide, oxidation) Tungsten, etc., Group 7 metal oxides (manganese oxide, etc.), Group 8 metal oxides (iron oxide, cerium oxide, etc.), Group 9 metal oxides (cobalt oxide, cerium oxide, cobalt and sodium) Materials, etc., Group 10 metal oxides (such as nickel oxide), Group 11 metal oxides (such as copper oxide), Group 12 metal oxides (such as zinc oxide, etc.), and typical metal oxides [for example, the second Group metal oxides (such as cerium oxide), Group 13 metal oxides (gallium oxide, indium oxide, etc.), Group 14 metal oxides (cerium oxide, tin oxide, etc.), Group 15 metal oxides (cerium oxide, etc.) As a composite oxide containing a plurality of such metals, for example, a Group 11 metal and a transition metal (Group 11 metal) can be exemplified. a composite oxide of a transition metal other than (for example, a composite oxide of copper such as CuYO ₂ and a metal of a Group 3 metal), a composite oxide of a Group 11 metal and a typical metal (for example, CuAlO ₂ , CuGaO ₂ , CuInO _{2 ,} etc.) a composite oxide of copper and a Group 13 metal; a composite oxide of copper such as SrCu ₂ O ₂ and a metal of Group ₂ ; a composite oxide of silver such as AgInO ₂ and a metal of Group 13).

The foregoing metal oxide also includes the plurality of metals and An oxide of a Group 16 element other than oxygen [for example, a composite oxysulfide of a Group 11 metal and a transition metal (a transition metal other than a Group 11 metal) (for example, a composite oxysulfide of copper such as LaCuOS and a metal of Group 3) ), a Group 11 metal and a transition metal (a transition metal other than the Group 11 metal) and a composite oxygen selenide (for example, a composite oxyselenide of copper such as LaCuOSe or a Group 3 metal), and the like.

Further, the semiconductor may be a metal nitride (such as tantalum nitride), a metal phosphide (InP or the like), a metal sulfide (for example, CdS, copper sulfide (CuS, Cu ₂ S), or a composite sulfide (for example, Group 11 of the periodic table). a composite sulfide of a metal and a typical metal (for example, copper such as CuGaS ₂ or CuInS ₂ and a composite sulfide of a metal of Group 13 of the periodic table), etc., metal selenide (CdSe, ZnSe, etc.), metal halide (CuCl, a metal compound (or alloy) such as CuBr or the like, a metal of Group 13 of the periodic table - a metal compound of Group 15 (GaAs, InSb, etc.), a metal of Group 12 of the periodic table, a metal compound of Group 16 (CdTe, etc.); Body (for example, palladium, platinum, silver, gold, rhodium, ruthenium) and the like.

Semiconductors can also be semiconductors that have been doped with other elements. . The semiconductor can also be an n-type semiconductor or a p-type semiconductor. As a typical n-type semiconductor, a metal oxide of Group 4 of the periodic table (titanium oxide or the like), a metal oxide of Group 5 of the periodic table (cerium oxide, cerium oxide, etc.), and a metal oxide of Group 12 of the periodic table can be exemplified (oxidation) Zinc or the like), a metal oxide of Group 13 of the periodic table (such as gallium oxide or indium oxide), a metal oxide of Group 14 of the periodic table (such as tin oxide), or the like.

The representative p-type semiconductor can be exemplified by a metal oxide of a Group 6 of the periodic table (such as chromium oxide), a metal oxide of Group 7 of the periodic table (manganese oxide or the like), and a metal oxide of Group 8 of the periodic table (iron oxide, etc.). , Group 9 metal oxides of the periodic table (cobalt oxide, ruthenium oxide, etc.), metal oxides of Group 10 of the periodic table (nickel oxide, etc.), metal oxides of Group 11 of the periodic table (copper oxide, etc.), Table 15 of the periodic table a metal oxide of a group (such as cerium oxide), a metal of a group 11 of the periodic table, and a composite oxide of a transition metal or a typical metal (for example, CuYO ₂ , CuAlO ₂ , CuGaO ₂ , CuInO ₂ , SrCu ₂ O ₂ , AgInO _{2 ,} etc.), Complex oxysulfide of Group 11 metals and transition metals of the periodic table (such as LaCuOS, etc.), complex oxyselides of Group 11 metals and transition metals of the periodic table (such as LaCuOSe, etc.), Group 11 metals of periodic table and typical metals Composite sulfides (for example, CuGaS ₂ , CuInS _{2 ,} etc.) and the like.

These semiconductors can also be used individually or in combination of 2 or more types. Preferred semiconductors include metal oxides such as titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), gallium oxide (Ga ₂ O ₃ ), copper- Aluminum oxide (CuAlO ₂ ), cerium oxide (IrO), nickel oxide (NiO), dopants of such metal oxides; barium titanate, barium titanate, etc.; cadmium sulfide. Among these semiconductors, titanium oxide, zinc oxide, tin oxide, and the like are particularly preferable. Particularly, among the n-type semiconductors, an n-type metal oxide semiconductor such as titanium oxide (TiO ₂ ) is particularly preferable.

The crystal shape (crystalline form) of titanium oxide is rutile type, sharp Any of titanium ore type and brookite type can be used. The preferred titanium oxide is rutile or anatase titanium oxide. When anatase type titanium oxide is used, it is easy to form a photoelectric conversion layer which has high adhesion to a substrate over a long period of time. Further, the rutile-type titanium oxide is preferred from the viewpoint of conductivity and durability. Further, as described above, the titanium oxide may be titanium oxide doped with other elements.

Shape of a semiconductor (for example, a metal oxide such as titanium oxide) It is not particularly limited, and may be in the form of particles, fibers (or needles or rods), plates, or the like. A preferable semiconductor form may be a particle shape, a needle shape or a fiber shape, and a particulate semiconductor (semiconductor particle) may be used.

Average particle size of semiconductor particles (particle or acicular semiconductor) The diameter (average primary particle diameter) may be selected from the range of about 1 to 1000 nm (for example, 1 to 700 nm), or may be a general nanometer size (for example, 1 to 500 nm (for example, 2 to 400 nm), preferably 3 to 300 nm (for example, 4 to 200 nm), and more preferably 5 to 100 nm (for example, 6 to 70 nm). It may be 50 nm or less, for example, 1 to 50 nm (for example, 2 to 40 nm), preferably 3 to 30 nm (for example, 4 to 25 nm), more preferably 5 to 20 nm (for example, 6 to 15 nm), and generally 10 or less. ~50nm or so. The nano-sized semiconductor particles have high transparency to visible light and can efficiently photoelectrically convert incident light having a wavelength range containing at least visible light.

The average fiber diameter of the acicular (or fibrous) semiconductor can also be For example, it is 1 to 300 nm, preferably 10 to 200 nm, and more preferably about 50 to 100 nm. Further, the average fiber length of the acicular (or fibrous) semiconductor may be from 10 to 2,000 nm, preferably from 50 to 1,000 nm, more preferably from about 100 to 500 nm. The aspect ratio of the acicular semiconductor may be, for example, 2 to 200, preferably 5 to 100, and more preferably about 20 to 40. Further, the acicular or fibrous semiconductor may form a nanofiber (for example, titanium oxide nanofiber (TNF)) or a nanotube (for example, a titanium oxide nanotube (TNT)).

The specific surface area of the semiconductor (for example, a particulate or fibrous semiconductor) may be, for example, 1 to 600 m ² /g, preferably 2 to 500 m ² /g, and more preferably about 3 to 400 m ² /g. In particular the specific surface area of the semiconductor particles may, for example, 5 ~ 600m ² / g (e.g. 10 ~ 550m ² / g), preferably 20 ~ 500m ² / g (e.g. 30 ~ 450m ² / g), and then preferably 40 to 400 m ² /g (for example, 50 to 350 m ² /g), or 50 m ² /g or more (for example, 50 to 500 m ² /g, preferably 75 to 450 m ² /g, and more preferably 100 to 400 m ² /g, especially 150 to 350 m ² /g (for example, 200 to 350 m ² /g)]. Further, the fibrous or needle-shaped semiconductor may have a specific surface area of 1 to 100 m ² /g, preferably 2 to 70 m ² /g, more preferably 3 to 50 m ² /g (for example, 4 to 30 m ² /g). about.

Also, semiconductors can be used as commercially available products, and they can also be used. The method is synthesized to use. For example, a dispersion of titanium oxide can borrow It is obtained by the method described in Japanese Patent No. 4522886 or the like.

Among various coating compositions, the type of semiconductor can also be phase Same or different.

(ionic adhesive or ionic polymer)

In the present invention, by combining a semiconductor and an ionic polymer (hereinafter referred to as an ionic binder), a photoelectric conversion layer having good photoelectric conversion characteristics can be formed even without sintering. The reason for this is unclear. Since ionic polymer bonds (chemical bonds, hydrogen bonds, etc.) are immobilized on semiconductors (especially nano-sized semiconductor particles (semiconductor nanoparticles)], not only semiconductors are promoted. The dispersion stability is also electronically coupled to the excited state of the semiconductor, and can function as an electrolyte (solid electrolyte) for transporting charges from the semiconductor. Further, when the ionic polymer acts as a binder and the photoelectric conversion characteristics are maintained for a long period of time, the adhesion to the photoelectric conversion layer (or semiconductor) of the substrate can be improved.

Further, the formation of the photoelectric conversion layer may be selected according to the type of the semiconductor, for example, (i) the n-type semiconductor may also select an ionic polymer containing an anionic polymer, and (ii) the p-type semiconductor. An ionic polymer comprising a cationic polymer can be selected.

The ionic polymer (ionic polymer) may be an electrolyte polymer (ie, a polymer electrolyte), or an anionic polymer, a cationic polymer, or an amphoteric polymer (having an anionic group and a cationic group). An anionic polymer or a cationic polymer (particularly an anionic polymer) can be generally used as the polymer or the like. In particular, the ionic polymer may also be an ion exchange resin (or ion exchanger or solid polymer electrolyte). Ionic polymers can also be separate Or a combination of two or more types.

Anionic polymers generally have an acid group (or an acidic group), For example, a carboxyl group, a sulfo group (or a sulfonic acid group), or the like may have a single acid group (or an acidic group), or may have a plurality of different acid groups (or acidic groups). Also, some or all of the acid groups may be neutralized.

As an representative anionic polymer, it can be exemplified as a positive ion a sub-exchange resin (cationic ion exchange resin, acid type ion exchange resin), for example, a weakly acidic cation exchange resin having a carboxyl group, a strongly acidic cation exchange resin having a sulfonic acid group (sulfo group), and a weakly acidic cation exchange resin capable of For example, a (meth)acrylic resin (for example, poly(meth)acrylic acid; a (meth)acrylic acid such as a (meth)acrylic acid-styrene copolymer and a copolymer with a copolymerizable monomer), or a carboxyl group; A fluorine-containing resin (perfluorinated carboxylic acid resin) or the like.

Preferred anionic polymers comprise a strongly acidic cation exchange resin. As the strongly acidic ion exchange resin, a styrene resin having a sulfo group (for example, a sulfonate of a polystyrenesulfonic acid or a styrene polymer) or the like; a fluorine-containing resin (or a fluororesin) having a sulfonic group, for example, a fluorosulfonic acid having a hydrophobic poly(fluoro C _2-3 alkylene) backbone, and a fluoro C _2-8 alkyl side chain having a sulfo group or a fluorine C _2-8 alkyl ether side chain having a sulfo group Resin, etc. Examples of the fluorosulfonic acid resin include a fluoroolefin (perfluoro C _2-3 olefin such as tetrafluoroethylene) and a sulfofluoroalkyl-fluorovinyl ether (sulfoperfluoroalkyl-perfluorovinyl ether). Copolymers such as tetrafluoroethylene and [2-(2-sulfotetrafluoroethoxy)hexafluoropropoxy]trifluoroethylene or [2-(2-sulfotetrafluoroethyl)hexafluoro A fluorosulfonic acid resin (particularly a perfluorosulfonic acid resin) such as a copolymer of propoxy]trifluoroethylene or the like]. Further, the fluorine-containing resin having a sulfo group can be obtained by DuPont under the trade name "Nafion" series or the like, or can be obtained in the form of an aqueous solution or an aqueous dispersion.

Cationic polymers generally have a basic group (alkali group) , for example, an amine group [for example, an amine group, a substituted amine group (for example, a mono- or dialkylamino group such as a dimethylamino group), a first-stage, a second-order or a third-order amine group], an imine group ( -NH-, -N<), a fourth-order ammonium salt group (for example, a trialkylammonium salt group such as a trimethylammonium salt group), or the like, may have a single basic group, or may have a plurality of basic types of different kinds. base. Also, a basic group may be partially or completely neutralized.

The representative cationic polymer may, for example, be an anion exchange resin (anionic ion exchange resin or an alkali ion exchange resin), for example, an allylamine monomer (for example, allylamine, diallylamine, or a mono- or copolymer of allylalkylamine (diallylmethylamine, diallylethylamine, etc.) or a copolymer of an allylamine-based monomer and a copolymerizable monomer [eg, a polyolefin) Propylamine, allylamine-dimethylallylamine copolymer, diallylamine-sulfur dioxide copolymer, etc.; single or copolymer of vinylamine monomer (for example, polyvinylamine, etc.) a mono- or copolymer [amino)alkyl (meth)acrylate (for example, N,N-dimethylaminoethyl (meth)acrylate, (methyl) An N,N-dialkylamino C _1-4 alkyl (meth)acrylate such as N,N-dimethylaminopropyl acrylate, or an aminoalkyl (meth) acrylamide (for example) a single or copolymer such as N,N-dialkylamino C _1-4 alkyl (meth) acrylamide such as N,N-dimethylaminoethyl (meth) acrylamide or the like] a heterocyclic amine polymer [eg, an imidazole polymer (eg, polyethyl b) Amidazole-based polymer (for example, polyvinylpyridine), a pyrrolidone-based polymer (for example, polyvinylpyrrolidone), etc., an amine-modified resin [amine-modified epoxy resin, amine-modified oxime) A resin or the like], a mono- or copolymer of an imine monomer (for example, a polyalkyleneimine (for example, a polyethylenimine) or the like), a fourth-order ammonium-based polymer, or the like.

As the fourth-order ammonium salt-based polymer, a polymer in which the amine group and the imine group of the above-exemplified amine-based polymer and imine polymer are subjected to a fourth-order ammonium salt, for example, N, N can be exemplified. , N-trialkyl-N-(meth) propylene oxiranyl ammonium salt [eg trimethyl-2-(methyl) propylene oxime oxyethyl ammonium chloride, N, N-dimethyl chloride a mono- or copolymer of a tri-C _1-10 alkyl (meth) propylene oxime C _2-4 alkyl ammonium salt of -N-ethyl-2-(methyl) propylene oxiranyl ammonium; Alkylalkylammonium salt-based polymers, such as N,N,N-trialkyl-N-(vinylaralkyl)ammonium salts (eg, trimethyl-p-vinylbenzylammonium chloride, chloride N) , N-dimethyl-N-ethyl-p-vinylbenzylammonium, N,N-diethyl-N-methyl-N-2-(4-vinylphenyl)ethylammonium chloride, etc. Tri-C _1-10 alkyl (vinyl-C _6-10 aryl C _1-4 alkyl) ammonium salt), N,N-dialkyl-N-aralkyl-N-(vinyl aralkyl An ammonium salt (for example, N,N-di-C _1-10 alkyl-NC _6-10 aryl C _1-4 such as N,N-dimethyl-N-benzyl-p-vinylbenzylammonium chloride) alkyl -N- (vinyl -C _6-10 aryl C _1-4 alkyl) ammonium salt)] and the like mono- or copolymers; cationized cellulose having [containing e.g. Hydroxy cellulose derivatives (e.g., hydroxyethyl cellulose, hydroxy C _2-4 alkyl cellulose) and Level 4 ammonium salt (e.g. a trialkylammonium salt group, etc.) an epoxy compound (e.g. N, N A reaction product of N-trialkyl-N-glycidyl ammonium salt], a polymer obtained by introducing a fourth-order ammonium salt group into a styrene-based resin, or the like.

Also cationic cellulose (cationized cellulose) The product name "Jeruna" was obtained from Daicel Co., Ltd.; the polyallylamine system was able to obtain the trade name from Nittobo Medical Co., Ltd. "PAA" series; amine modified oxime resin is available from Shin-Etsu Chemical Co., Ltd. under the trade name "KF" series.

Among the fourth-order ammonium salt-based polymers, the salt system can be mentioned Examples of halide salts (e.g., chlorides, bromides, iodides, etc.), carboxylates (e.g., carboxylates such as acetates), sulfonates, and the like.

A preferred cationic polymer is exemplified as containing the fourth A strongly basic cationic polymer (anion exchange resin) such as a quaternary ammonium salt-based polymer.

Also, the ionic polymer may be only anionic or cationic. It may be composed of a daughter polymer or a combination of other ionic polymers (for example, an amphoteric polymer). The ratio of the anionic or cationic polymer to the entire ionic polymer may be, for example, 30% by weight or more (for example, 40 to 99% by weight), preferably 50% by weight or more (for example, 60 to 98% by weight). Further, it is preferably 70% by weight or more (for example, 80 to 97% by weight).

The pH of the aqueous solution or aqueous dispersion of the ionic polymer is It is acidic, neutral or alkaline, and the pH can be selected according to the ionic polymer. For example, the pH of the ionic polymer (25 ° C) may be selected from the range of 10 or less (for example, 0.1 to 8), and may be, for example, 0.2 to 7 (for example, 0.3 to 5), preferably 0.5 to 4 (for example, 0.7 to). 3), preferably about 1~3.

If you use an ionic polymer with a higher pH, you can The condensation of a semiconductor (for example, titanium oxide nanoparticles) is suppressed, and the photoelectric conversion characteristics can be further improved. There is also a case where the adhesion to the substrate can be improved efficiently. The pH (25 ° C) of the plasma polymer may be, for example, 3 or more (for example, 4 to 14), preferably 5 or more (for example, 6 to 13), and more preferably 7 or more (for example, 7 to 12).

In particular, anionic polymers (such as strongly acidic ion exchange The pH of the resin or the ionic polymer containing the anionic polymer (25 ° C) may be, for example, 4 to 14 (for example, 5 to 13), preferably 5.5 to 12 (for example, 7 to 12), and more preferably 6~11 (for example, 7~9).

Cationic polymer (eg strong basic anion exchange tree) The pH (25 ° C) of the lipid or the ionic polymer containing the cationic polymer can be selected from the range of 5 or more (for example, 6 to 14), and may be, for example, 7 to 14 (for example, 8 to 13), preferably. It is 9 to 13 (for example, 9.5 to 13), and more preferably about 10 to 13.

The pH system can be neutralized by a common method (for example, alkali-neutralized The method is adjusted by acid neutralization, etc.). Further, among the acid groups which have been neutralized, as the counterion, for example, an alkali metal (e.g., lithium, sodium, potassium, etc.), a tertiary amine or the like may be used.

There are also ionic polymers (anionic polymers, etc.) It may also have a crosslinked structure, but is preferably an ionic polymer which does not have a crosslinked structure (or a very low degree of crosslinking).

Ion exchange (ion exchange resin), ion exchange The capacity may also be 0.1 to 5.0 meq/g (for example, 0.15 to 4.0 meq/g), preferably 0.2 to 3.0 meq/g (for example, 0.3 to 2.0 meq/g), and more preferably 0.4 to 1.5 meq/g ( For example, about 0.5~1.0meq/g).

Also, if the molecular weight of the ionic polymer is in the solvent The range in which it is dissolved or dispersed is not particularly limited. Further, a fluorine-containing resin (fluororesin) having a sulfo group is dispersed in a nanometer order, and there is a case where the molecular weight cannot be accurately measured.

It is generally considered that the photoelectric conversion efficiency is obtained if the proportion of the binder becomes large By using an ionic polymer, not only the photoelectric conversion layer having high photoelectric conversion characteristics but also the adhesion to the photoelectric conversion layer of the conductive substrate and the adhesion of the adjacent photoelectric conversion layer can be improved. Therefore, in the present invention, even when the ratio of the amount of the ionic polymer to the semiconductor is large, the photoelectric conversion characteristics and the adhesion to the substrate can be improved. The ratio of the ionic polymer can be selected from the range of about 1 to 100 parts by weight based on 100 parts by weight of the semiconductor, and may be, for example, 3 to 75 parts by weight (for example, 4 to 60 parts by weight), preferably 5 to 50 parts by weight. The parts by weight (e.g., 6 to 40 parts by weight), more preferably 7 to 30 parts by weight (e.g., 10 to 25 parts by weight), may be usually 5 to 20 parts by weight (e.g., 10 to 15 parts by weight). Further, if the amount of the ionic polymer is too small, the adhesion may be lowered, and if it is too large, the photoelectric conversion characteristics may be lowered.

There are also a variety of coating compositions, species of ionic polymers Classes can also be the same or different.

(dye)

The dye which functions as a sensitizer (sensitizing dye or photoinhibitor) may be, for example, an organic dye or an inorganic dye (for example, a carbon pigment, a chromate pigment, a cadmium pigment, a ferrocyanide pigment, or a metal). Oxide pigment, citrate pigment, phosphate pigment, etc.). The dyes may be used alone or in combination of two or more.

As an organic dye (organic dye or organic pigment), capable of The commonly used or well-known dyes can be exemplified by a ruthenium complex dye, a ruthenium complex dye, a porphyrin dye (magnesium porphyrin, zinc porphyrin, etc.), a chlorophyll dye (chlorophyll, etc.), a xanthene system. Dyes (rhodamine B, sulfo rhodamine B, erythrosine, etc.), Cyanine (or polymethine) dyes (merocyanine, quinocyanine, cryptocyanine, etc.), phthalocyanine dyes (The dye is a dye called "TT1", and may have a plurality of alkyl groups (three third-order butyl groups, etc.) and a carboxyl group) for improving the solubility in an organic solvent, an azo dye, and an anthraquinone dye. Dyes, perinone dyes, coumarin dyes, anthraquinone dyes, quinone imine dyes, diphenylmethane dyes, triphenylmethane dyes, indigo dyes, pyrazolone Dye, stilbene dye, thiazole dye, quinoline dye, acridine dye, anthraquinone dye, squarylium dye, azomethine dye, quinophthalone dye , quinacridone dyes, indoline dyes (dyes called "D149" dyes, etc.), isoporphyrin dyes, nitroso dyes, pyrrole Pyrropilyrrole dyes, xanthene dyes, carbazole dyes (for example, "MK-2" dyes) Dye (2-cyano-3-[5''--(9-ethyl-9H-indazole-3-indenyl]-3',3",3''',4-tetra-n-hexyl-[ 2,2',5',2",5",25''']-quaternary thiophene-5-mercapto]acrylic acid), basic dyes (methylene blue, basic blue 12, etc.) )Wait.

Further, the dye may be a thiophene-based or acrylic dye (3-{5'-[N,N-bis(9,9-dimethylindol-2-yl)phenyl]-2,2'-dithiophene -5-yl}-2-cyanoacrylic acid (in the case of a dye known as "JK2"), 2-cyano-3-(5-(4-ethoxyphenyl)thiophen-2-yl)acrylic acid ( There is a case called "P5" dye), etc., thiazole dye (3-carboxymethyl-5-(3-(4-sulfobutyl)-2(3H)-benzothiazolidine)-2 - thio-4-tetrahydrothiazolone sodium salt ("NK3705" dye), etc.), metal-free panchromatic dye (for example, as a donor electron donor) And dyes introduced as rhodamine as an electron acceptor).

As the ruthenium complex dye, ruthenium pyridine can be exemplified A complex, such as a bipyridyl complex of hydrazine [eg, cis-bis(isothiocyanate) bis(2,2'-bipyridyl-4,4'-dicarboxylate) hydrazine (II) Bis-tetrabutylammonium (alias: "N719" dye, "Red Dye"), cis-bis(isothiocyanate) bis(2,2'-bipyridyl-4,4'-dicarboxylate ) 钌 (II) (alias: "N3" dye), cis-bis (isothiocyanate) (2,2'-bipyridyl-4,4'-dicarboxylate) (2,2' -bipyridyl-4,4'-dimercapto)anthracene (II) (alias: Z-907 dye), cis-bis(isothiocyanate) bis(2,2'-bipyridine-4,4 '-Dicarboxylate group) ruthenium (II), cis-bis(cyanide) (2,2'-bipyridyl-4,4'-dicarboxylate) ruthenium (II), dichlorochloride ( 2,2'-bipyridyl-4,4'dicarboxylate) ruthenium (II), cis-bis(thiocyanate) bis(2,2'-biquinolinyl-4,4'- Dicarboxylate) ruthenium (II), etc.; ruthenium terpyridine pyridine complex [eg tris(isothiocyanate) ruthenium (II)-2,2':6',2''-terpyridine -4,4',4''-tris-tetrabutylammonium tricarboxylate (alias: "N749" dye, "Black Dye"), etc.]. Most of the pyridine-based complexes are obtained by disposing a bipyridylcarboxylic acid unit (selected from at least one of a bipyridine carboxylic acid, a bipyridine dicarboxylic acid, and a terpyridine carboxylic acid) and an isothiocyanate group. High photoelectric conversion efficiency. The ruthenium complex dye also contains a complex with phenanthroline and the like.

Dyes (pyridine-containing complexes containing ruthenium) can also be used in the city. For sale, it can also be synthesized by referring to well-known literature, for example, J. Am. Chem. Soc. 115 (1993) 6382, J. Am. Chem. Soc. 123 (2001) 1613, Inorganica Chimica Acta. 322 (2001) 7, and the like. .

These dyes may be used alone or in combination of two or more. Further, although a plurality of dyes may be combined to expand the absorption wavelength range, if a plurality of dyes are mixed and loaded or fixed to a semiconductor, the eneray transition between dyes may be deactivated and the photoelectric conversion efficiency may be lowered.

A plurality of coating compositions (or coating agents) may be individually contained Dyes having different absorption wavelength ranges or absorption peak wavelengths can contain a plurality of dyes in a laminated form by a multilayer photoelectric conversion layer, thereby greatly improving photoelectric conversion efficiency. For example, the plurality of dyes included in the photoelectric conversion layer of the laminated form are preferably absorbable over the entire wavelength range of the entire solar radiation spectrum, and are preferably capable of absorbing the entire light, at least the visible light range, or the visible light range (for example, the light having a wavelength range of 400 to 700 nm). Preferably, it is a visible light range of a wavelength range of an ultraviolet range (for example, 200 to 400 nm) and/or an infrared range (for example, 700 to 1800 nm), particularly a wavelength range of about 200 to 1500 nm (for example, 300 to 1300 nm). Further, as described in the different wavelength ranges, the wavelengths of the visible light range, the ultraviolet range, and the infrared range are not strictly numerical values, and the wavelengths of the above ranges are described as approximate indexes. Therefore, the visible light range can also be, for example, a wavelength range of 300 to 800 nm (for example, 380 to 730 nm, particularly 400 to 700 nm).

A variety of dyes can also be classified, for example, in the ultraviolet range a dye that absorbs a wavelength range or absorbs a sharp wavelength, a dye having an absorption wavelength range or an absorption peak wavelength in the visible light range, and a dye having an absorption wavelength range or an absorption peak wavelength in the infrared range; and can be classified into an ultraviolet range and a visible light range. Dyes that absorb the wavelength range or absorb the peak wavelength and have an absorption wavelength range in the infrared range A dye that absorbs a sharp wavelength; it can also be classified into a dye having an absorption wavelength range or an absorption peak wavelength in the ultraviolet range and the visible range, and a dye having an absorption wavelength range or an absorption peak wavelength in the visible range and the infrared range. If the representative dye absorption wavelength range is exhibited, for example, the "JK2" dye exhibits broad absorption in the wavelength range of 450 to 550 nm, the "P5" dye exhibits an absorption range of about 390 to 430 nm, and the "N719" dye has absorption at 540 nm. The peak exhibits absorption in the wavelength range of about 380-410 nm and the wavelength range of 530-550 nm. The "N749" dye has an absorption peak near 600 nm, a wavelength range of about 370-420 nm, and a wavelength range of about 590-610 nm. Absorption, "MK-2" dye has an absorption peak at 480 nm, exhibits a wide absorption range in the wavelength range of 450 to 650 nm, and a phthalocyanine dye such as "TT1" dye exhibits a sharp absorption range around 680 to 710 nm. . Therefore, the present invention combines a plurality of dyes having different absorption wavelength ranges to form a laminated photoelectric conversion layer.

There are also a variety of dye absorption wavelength ranges or absorption spikes The length (especially the absorption peak wavelength) is preferably shifted by 10 nm or more (for example, about 10 to 200 nm), preferably 20 nm or more (for example, about 20 to 200 nm), and more preferably 30 nm or more (for example, about 30 to 150 nm). Generally, the distance is usually 10 to 150 nm (for example, 25 to 120 nm), preferably 20 to 100 nm (for example, 30 to 100 nm or 30 to 80 nm).

More specifically, it can also be dyed by modulating the dye containing "P5" The first coating composition, the second coating composition containing the "N719" dye, and the third coating composition containing the "N749" dye, are sequentially applied to the conductive substrate to form a laminated photoelectric layer. Conversion layer The coating composition containing the "N719" dye and the second coating composition containing the "N749" dye may be applied to the conductive substrate in order to form a laminated photoelectric conversion layer. Further, if it is a combination which does not impair or can improve conversion efficiency, each coating composition is not limited to a single dye, and may contain a plurality of dyes.

Also dyes are generally loaded or attached (or fixed) to the semiconducting The form of the body (or the surface of the porous semiconductor) is included in the photoelectric conversion layer. The dye may also be attached (or fixed) to the semiconductor by adsorption (physical adsorption), chemical bonding, or the like. Therefore, it is also possible to select a dye which is easy to adhere or bond to a semiconductor, for example, a dye having a functional group such as a carboxyl group, an ester group, a sulfo group or a cyano group (for example, an anthraquinone dye having a carboxyl group such as a "N719" dye or a "N749" dye; a phthalocyanine dye having a carboxyl group such as a dye of TT1"; an oxazole dye having a carboxyl group and a cyano group such as a "JK2" dye, a "P5" dye or a "MK-2" dye, and a thiophene dye or an acrylic dye; A thiazole-based dye having a sulfo group or the like, such as a "NK3705" dye. These dyes are considered to be not only detachable from a semiconductor surface such as titanium oxide but also difficult to be detached, and are electronically coupled with an excited state of a semiconductor, which is advantageous in improving photoelectric conversion efficiency.

The ratio of the dye (adhesion or adsorption ratio) is, for example, semi-conductive The body may be associated with an ionic binder or an ionic polymer, or may be selected according to the following formula.

0<(I _A ×I _S +D _A ×D _S )/S _S ≦1

(In the formula, I _A represents the number of ionic groups in the ionic binder or ionic polymer, I _S represents the occupied area of an average of 1 ionic group, and D _A represents the number of dyes (dye molecules), D _S Indicates the area occupied by an average of 1 dye, and S _S represents the surface area of the semiconductor.)

In the above formula, I _A is the total number of ionic groups, and can be multiplied by an ionic binder or an ionic polymer, for example, by weight (g) of an ionic binder or an ionic polymer and a ruthenium number of argon. The ion exchange capacity (meq/g) is calculated, generally I _A × I _S <S _S . Occupied area ^{_{(m 2) I S, D}} S is an individual ionic groups, the area occupied by one molecule of a dye (m ^2), as the area occupied by a projection-based molecules can be used in the largest projected area.

The coating composition may comprise an amount of adsorption or energy to the semiconductor An amount of the dye is fixed, and the ratio of the dye may be, for example, 0.1 to 20 parts by weight (for example, 0.5 to 15 parts by weight), preferably 1 to 10 parts by weight (for example, 1.5 to 8 parts by weight) based on 100 parts by weight of the semiconductor. Further, it is preferably about 2 to 6 parts by weight (for example, 3 to 5 parts by weight).

The coating composition may also contain a solvent. The solvent may be water and/or an organic solvent. Examples of the organic solvent include alcohols (alkanols such as methanol, ethanol, isopropanol, and butanol) and hydrocarbons (aromatic hydrocarbons such as toluene and xylene). , aliphatic hydrocarbons such as hexane, alicyclic hydrocarbons such as cyclohexane), halogenated hydrocarbons (such as halogenated hydrocarbons such as dichloromethane and chloroform), and esters (ethyl acetate, butyl acetate, etc.) ), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.), ethers (two a chain ether such as a cyclic ether such as an alkane or tetrahydrofuran; a chain ether such as diisopropyl ether, propylene glycol monomethyl ether or diethylene glycol dimethyl ether; or a celluloid (methicone) Glycol monoalkyl ether of bismuth, butyl acesulfame, etc., bis-glycol monoalkyl of carbitol (methyl carbitol, ethyl carbitol, butyl carbitol, etc.) Ether), cellosolve acetate (cetoacetate, etc., and propylene glycol monomethyl ether monoacetate classified as cytosine acetate) Etc.), carbitol acetate, nitrile (for example, acetonitrile, benzonitrile, etc.), nitro solvent (for example, nitrobenzene, etc.). The solvent may be used alone or in combination of two or more.

a solid component (or non-volatile) in a solvent-containing composition The ratio of the component) may be, for example, 0.1 to 60% by weight (for example, 1 to 50% by weight), preferably 5 to 40% by weight (for example, 10 to 30% by weight), depending on the coating method and the like. In the present invention, the solid content of the semiconductor may be a high concentration, and the dispersion stability of the semiconductor can be improved.

Also, the coating composition can be mixed by a common method, such as mixing It can be prepared by combining a semiconductor (titanium oxide or the like) with an ionic polymer and a dye, or a non-sintered semiconductor (non-sintered titanium oxide or the like) which has been previously adsorbed or immobilized on a semiconductor (etc.) and an ionic polymer. To modulate. In general, a solution in which a ionic polymer is mixed or dispersed (such as an aqueous dispersion) and a semiconductor (such as titanium oxide) and a dye are usually used. A further variety of coating compositions can also modulate dyes having different absorption wavelength ranges or absorption peak wavelengths. Further, the pH of the coating composition containing the solvent is not particularly limited, and can be selected from the same range as the pH of the ionic polymer, and the pH adjustment system can be carried out at an appropriate stage, for example, an ionic polymer solution or The pH of the dispersion is remixed with the semiconductor dye.

The coating composition of the present invention is laminated by coating The photoelectric conversion layer is advantageous for forming a laminated photoelectric conversion layer or a laminated photoelectric conversion body (laminate) having different dye ranges in the thickness direction.

[Laminated photoelectric converter and its manufacturing method]

The multilayer photoelectric conversion body of the present invention includes a photoelectric conversion layer in which a multilayer photoelectric conversion layer is laminated, and can be generally formed on a conductive substrate. Conductive The substrate may include only a conductor, but may generally include a base substrate and a conductive layer (or conductive film) formed on the substrate.

As the base substrate, an inorganic substrate (for example, glass) can be used. a substrate, a ceramic substrate, or the like, a plastic substrate, or a plastic film [for example, a polyester resin (for example, polyethylene terephthalate or polybutylene terephthalate), a polycarbonate resin, or a cycloolefin resin) , a polypropylene resin, a cellulose resin (such as cellulose triacetate), a polyether resin (such as polyether oxime), a polysulfide resin (such as polysulfurized benzene), or a polyimide resin. a substrate or a film formed of plastic, etc.]. In the present invention, since a sintering step of a semiconductor is not required, a plastic substrate (plastic film) can be used as the base substrate. The base substrate is generally a transparent substrate.

The conductive layer can be, for example, a conductive metal oxide [example Such as tin oxide, indium oxide, zinc oxide, antimony doped metal oxide (cerium doped tin oxide, etc.), tin doped metal oxide (tin doped indium oxide, etc.), aluminum doped metal oxide (aluminum doped It is formed by a zinc oxide-doped metal oxide (such as gallium-doped zinc oxide), a fluorine-doped metal oxide (such as fluorine-doped tin oxide), or the like. These conductive layers may be formed singly or in combination of two or more of the above components. The conductive layer can also generally be a transparent conductive layer.

Can be coated sequentially by applying multiple coating compositions (or inks) The laminate is laminated on a conductive substrate (or a conductive layer thereof) to form a laminated photoelectric converter on the conductive substrate. There are also a plurality of coating compositions (or inks) which individually contain a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths. This method is capable of forming each photoelectric conversion layer without sintering. Therefore, the laminated photoelectric conversion system individually contains a plurality of dyes in each of the photoelectric conversion layers in a layered form.

The number of layers of the photoelectric conversion layer by a plurality of coating compositions There is no particular limitation, and may be, for example, 2 to 10 layers (for example, 2 to 7 layers), and generally 2 to 5 layers (for example, 2 to 4 layers), particularly 2 or 3 layers. For example, a plurality of dyes having different absorption peak wavelengths or different absorption wavelength ranges may be used, and a multilayered photoelectric conversion layer of different wavelength ranges may be laminated. For example, the first photoelectric conversion layer including the first dye and the semiconductor, and the second photoelectric conversion layer including the second dye and the semiconductor may be laminated on the conductive substrate, or the third dye and the semiconductor may be further included. 3 photoelectric conversion layer is laminated on the second photoelectric conversion layer. In the multilayer photoelectric conversion layer, the absorption wavelength range or the absorption peak wavelength (especially the absorption peak wavelength) of the plurality of dyes is the same as described above, and each of the photoelectric conversion layers may be spaced apart from each other by, for example, 10 nm or more (for example, about 10 to 200 nm), in particular It is about 20~100nm (for example, 30~80nm), and it can also be about 10~150nm.

The coating sequence of various coating compositions (or inks) is not unique. In other instances, a laminate having a plurality of layers of photoelectric conversion layers (for example, adjacent photoelectric conversion layers) having different absorption wavelengths may be laminated, and any of the photoelectric conversion layers may contain dyes having mutually different absorption wavelength ranges or absorption peak wavelengths ( In particular, dyes having absorption peak wavelengths, the absorption peak wavelength or absorption wavelength range of a plurality of dyes and the stacking order (stacking position) of the photoelectric conversion layer may also be associated. For example, a photoelectric conversion layer that absorbs a short wavelength (for example, at least a wavelength in the visible light range or a wavelength in the ultraviolet range up to a visible light range) is placed at a longer absorption wavelength (for example, at least a near-infrared wavelength range, or a visible light range up to a near infrared ray). The photoelectric conversion layer of the range of wavelengths is closer to the incident side (light receiving side), and may be placed at an intermediate position between the incident side and the penetrating side. More specifically, if A first coating composition containing a first dye having an absorption peak wavelength or an absorption wavelength range in a short wavelength range, a second coating composition containing an absorption peak or a second dye having an absorption wavelength in a long wavelength range, and an absorption peak The third coating composition of the third dye having a wavelength or an absorption wavelength in the intermediate wavelength range may be in accordance with the order of the second coating composition/third coating composition/first coating composition, and the third coating composition/ The order of the second coating composition/first coating composition, the order of the second coating composition/the first coating composition/the third coating composition, and the like, and coating the photoelectric conversion layer from the incident side (conductive substrate or light receiving side) It is formed by a multilayer photoelectric conversion layer that penetrates the photoelectric conversion layer on the side.

Preferably, it will absorb short wavelengths (eg, at least visible light) The photoelectric conversion layer of the wavelength range or the ultraviolet range up to the wavelength of the visible light range is placed on the photoelectric conversion layer which absorbs longer wavelengths (for example, at least the wavelength of the near infrared range or the wavelength of the visible range to the near infrared range). The dye contained in the photoelectric conversion layer on the incident side (conductive substrate or light-receiving side) is closer to the absorption peak of the dye contained in the photoelectric conversion layer on the penetration side, and has an absorption peak wavelength in the short wavelength range. . That is, the multi-layer photoelectric conversion layer of the laminated layer is from the photoelectric conversion layer on the light-receiving side to the photoelectric conversion layer on the penetration side, and sequentially contains a plurality of dyes whose absorption wavelength range or absorption peak wavelength is continuously or sequentially transferred from a short wavelength to a long wavelength. . In other words, the light-receiving side forms a dye-sensitized photoelectric conversion layer containing a dye capable of absorbing a short wavelength range (for example, a short wavelength range of the visible light range), and the penetration side is formed to include a long wavelength range capable of absorbing (for example, a long wavelength range of the visible light range). The dye is dyed to increase the photoelectric conversion layer. In the multilayer photoelectric conversion layer, the photoelectric conversion layer on the light receiving side It may also contain a first dye having a short peak wavelength in the visible light range (for example, 300 to 600 nm, preferably 350 to 580 nm, and more preferably about 370 to 570 nm). The photoelectric conversion layer on the opposite side (penetrating side) of the light receiving side may also have a long wavelength range in the visible light range (for example, 550 to 800 nm, preferably 570 to 750 nm, and more preferably about 580 to 700 nm) having an absorption peak wavelength. The second dye. Further, the absorption peak wavelength of a plurality of dyes (especially the absorption peak wavelength of the first dye and the second dye, or the absorption peak wavelength of the dye contained in the adjacent photoelectric conversion layer), the photoelectric conversion layer on the light receiving side, and the light receiving side The photoelectric conversion layer on the opposite side (penetrating side) of the side may be at least 10 nm or more, and may be, for example, 10 to 200 nm (for example, 20 to 200 nm), preferably 30 to 200 nm (for example, 30 to 170 nm), and more preferably It is about 50~150nm, and it can also be about 30~150nm (for example, 50~130nm). For example, the absorption peak wavelength of the first dye is shorter than the absorption peak wavelength of the second dye, and may be, for example, 10 nm or more (for example, 10 to 200 nm, preferably 20 to 200 nm, as compared with the difference in peak wavelength). A shorter wavelength of about 50 to 150 nm.

The photoelectric conversion layer (layered body) of the laminated form is capable of For example, a plurality of coating compositions are sequentially applied to the conductive substrate in accordance with the relationship between the absorption peak wavelength or the absorption wavelength range of the plurality of dyes and the order of lamination of the photoelectric conversion layers. When the first to third coating compositions are used, the photoelectric conversion layer in the laminated form may be applied in the order of the first coating composition, the third coating composition, and the second coating composition, for example, to form a conductive substrate. It can be formed by coating in the order of the first coating composition/second coating composition/third coating composition.

The coating method is not particularly limited, such as air knife coating A roll coating method, a gravure coating method, a doctor blade coating method, a doctor blade method, a squeegee method, a dip coating method, a spray method, a spin coating method, an inkjet printing method, or the like. Further, after coating, the coating film may be dried at a predetermined temperature (for example, a temperature of about room temperature to about 150 ° C, preferably about 50 to 120 ° C). In the application of a plurality of coating compositions, in order to suppress the mixing of the dye at the interface of the adjacent photoelectric conversion layer, the step of applying the coating composition and the step of drying the coating film may be repeated to laminate the photoelectric conversion layer. The coating composition can be further coated on the dried photoelectric conversion layer formed by the drying step and dried to prevent the dye from entering in the boundary region of the adjacent photoelectric conversion layer, and can be sequentially and layerwise in the thickness direction. A variety of dyes are formed.

The invention can be heated at a high temperature (for example, above 500 ° C) The semiconductor is sintered (or calcined) to form a photoelectric conversion layer having high photoelectric conversion characteristics (further durability and adhesion to the substrate).

The total thickness of the photoelectric conversion layer in the laminated form can also be an example. For example, 0.1 to 100 μm (for example, 0.5 to 70 μm), preferably 1 to 50 μm (for example, 3 to 30 μm), and more preferably about 5 to 20 μm. Further, the thickness of each of the photoelectric conversion layers can be selected from the range of 0.01 to 50 μm (for example, 0.5 to 30 μm, particularly 1 to 15 μm) depending on the number of layers, the absorption coefficient of the dye, and the like. Further, each of the photoelectric conversion layers and the entire thickness can be freely adjusted by the number of coatings (the number of layers).

In order to efficiently convert incident light into photoelectrically, receive light The ratio of the thickness Tr of the photoelectric conversion layer on the side and the thickness Tt of the photoelectric conversion layer on the penetration side can be selected from the range of Tr/Tt=10/90 to 95/5 (for example, 20/80 to 90/10). Can also be 10/90~80/20 (for example, 20/80~ 75/25), preferably about 30/70~70/30 (for example, 40/60~65/35). When the thickness Tr of the photoelectric conversion layer on the light receiving side is increased, the incident light can be efficiently absorbed to improve the photoelectric conversion efficiency. In particular, it is preferable to form a photoelectric conversion layer capable of absorbing a short wavelength on the light receiving side, and to increase the thickness Tr of the photoelectric conversion layer on the light receiving side.

Laminated photoelectric converter formed on a conductive substrate The layer type dye-sensitized photoelectric conversion body or laminate has a conductive layer and a photoelectric conversion layer, and can be used as an electrode (photoelectrode) constituting a photoelectric conversion element. In particular, since a multilayer photoelectric conversion layer having different absorption light is formed, it becomes a single structure and can efficiently photoelectrically convert incident light from a short wavelength range to a long wavelength range. Therefore, the structure is simple and high conversion efficiency can be achieved.

[Photoelectric Conversion Element and Method of Manufacturing Same]

A photoelectric conversion element including a laminated photoelectric converter (photoelectrode) formed on a conductive substrate can be used for various applications in which photoelectric conversion can be performed, and can be utilized as a solar cell (dye sensitized solar cell).

The solar cell is provided with, for example, an electrode formed on the conductive The laminated photoelectric conversion body on the substrate, the counter electrode disposed opposite to the electrode (the photoelectric conversion layer side of the electrode), and the electrolyte phase (or electrolyte layer) sealed between the electrodes. The photoelectric conversion elements can be composed of the same steps as those for manufacturing the above-mentioned laminated photoelectric converter, for example, each coating composition contains a plurality of dyes having different absorption wavelength ranges or absorption peak wavelengths and different coating compositions containing the aforementioned dyes. a step of sequentially coating and laminating the conductive substrate, and an unsintered semiconductor to form a laminated layer A method of the step of laminating a photoelectric conversion body of a multilayer photoelectric conversion layer. The electrolyte phase (or electrolyte) is a sealant [for example, a thermoplastic resin (ionomer resin), a thermosetting resin (epoxy resin, a decane resin, etc.), etc.] The periphery of the two electrodes is sealed and sealed in a space or gap between the two electrodes.

When the semiconductor is an n-type semiconductor, the formation of the polar system is positive. When the semiconductor is a p-type semiconductor, the negative electrode is formed on the electrode (the laminated body is a positive electrode).

The pair of poles is the same as the above-mentioned laminated photoelectric converter, and has a guide An electric substrate and a catalyst layer (positive catalyst layer or negative catalyst layer) formed on the conductive substrate (or a conductive layer of the conductive substrate), a conductive layer or a catalyst layer and a layer of the opposite electrode The photoelectric conversion bodies (or electrodes) are arranged opposite each other. Also, a conductive layer having a reducing ability does not necessarily require a catalyst layer to be provided. The conductive substrate of the counter electrode may be a substrate on which a layer (conductive catalyst layer) having both a conductive layer and a catalyst layer is formed on the base substrate, in addition to the same substrate as described above. Further, the catalyst layer (positive electrode catalyst layer or negative electrode catalyst layer) is not particularly limited, and can be formed of a conductive metal (gold, platinum, or the like), carbon, or the like.

The catalyst layer (positive catalyst layer or negative catalyst layer) may also be non- The porous layer (or non-porous layer) may also be a porous layer. The porous layer (porous catalyst layer) may further include a porous catalyst component (porous catalyst component), or may include a porous component (porous component) and a catalyst component supported by the porous component. Combinations of these may also be included. That is, the porous layer (porous catalyst layer) has porosity and a catalytic function.

As a porous catalyst component, metal fine particles can be exemplified (for example, platinum black, etc.), carbon black [activated carbon, graphite, Ketjenblack, furnace black, acetylene black, carbon black (carbon black group), carbon nanotubes (carbon nanotubes) )and many more. These components may be used alone or in combination of two or more. Activated carbon or the like can also be used as the porous catalyst component.

As the porous component, in addition to the above porous carbon, Examples of the metal compound particles (for example, particles (fine particles) of the conductive metal oxide (for example, tin-doped indium oxide) exemplified above) and the like can be given. These components may be used alone or in combination of two or more. Further, as the catalyst component, a conductive metal (for example, platinum) or the like can be given.

The shape (or form) of the porous catalyst component and the porous component is not particularly limited, and may be particulate, fibrous or the like, and is preferably particulate. The average particle diameter of the particulate porous catalyst component and the porous component (porous particle) may be, for example, 1 to 1000 μm (for example, 10 to 500 μm), preferably 30 to 300 μm (for example, 40 to 200 μm), and then Preferably, it is about 50 to 150 μm (for example, 70 to 100 μm). The BET specific surface area of the porous catalyst component and the porous component may be, for example, 1 to 4000 m ² /g (for example, 20 to 3,000 m ² /g), preferably 50 to 2000 m ² /g (for example, 100 to 1,500 m ² /g). Further, it is preferably about 200 to 1000 m ² /g (for example, 300 to 500 m ² /g).

There is also a porous layer (porous catalyst layer) as needed, The binder component may be contained, for example, a resin component (for example, a thermoplastic resin such as a cellulose derivative (methylcellulose or the like); a thermosetting resin such as an epoxy resin). The ratio of the binder component is, for example, 0.1 to 50% by weight (for example, 1 to 40% by weight), preferably 2 to 30% by weight (for example, 3 to 30% by weight) based on the entire porous layer (porous catalyst layer). 20% by weight), more preferably about 5 to 15% by weight.

Most of the electrodes (opposite poles) have at least a porous layer Generally, at least a substrate (a substrate which may be a conductive substrate) and a porous catalyst layer are provided. The representative electrode (opposing pole) having a porous layer may be: (i) a porous catalyst layer including a conductive substrate and a porous catalyst component formed on the conductive substrate (or conductive layer) (ii) a porous catalyst comprising a conductive substrate and a porous component and a catalyst component (for example, a porous component containing a catalyst component) formed on the conductive substrate; Layer electrodes (or laminates), etc.

The thickness of the porous layer (porous catalyst layer) may be, for example, 0.1 to 100 μm, preferably 0.5 to 50 μm, and more preferably about 1 to 30 μm.

The electrolyte layer may also be formed of an electrolyte containing an electrolyte and a solvent, or may be formed of a solid layer (or colloid) containing an electrolyte. The electrolyte as the electrolytic solution is not particularly limited, and examples thereof include a general-purpose electrolyte such as a combination of a halogen (halogen molecule) and a halide salt [for example, a combination of a bromine and a bromide salt, a combination of an iodine and an iodide salt, etc.] . Examples of the counter ion (cation) constituting the halide salt include metal ions (for example, alkali metal ions (for example, lithium ions, sodium ions, potassium ions, cesium ions, etc.) and alkaline earth metal ions (for example, magnesium ions, calcium ions, etc.). And the like], a fourth-order ammonium ion [tetraalkylammonium salt, pyridinium salt, imidazolium salt (for example, 1,2-dimethyl-3-propylimidazolium salt), etc.]. The electrolyte may be used alone or in combination of two or more.

A preferred electrolyte system is a combination of iodine and an iodide salt, particularly a combination of iodine and a metal iodide salt [for example, an alkali metal salt (lithium iodide, sodium iodide, potassium iodide, etc.) and a fourth-order ammonium salt. .

The solvent as the electrolytic solution is not particularly limited, and Examples of alcohols (such as alkanols such as methanol, ethanol, butanol; glycols such as ethylene glycol, diethylene glycol, and polyethylene glycol), nitriles (acetonitrile, methoxyacetonitrile, propionitrile, and pentane) Nitrile, 3-methoxypropionitrile, benzonitrile, etc.), carbonates (ethylene carbonate, propylene carbonate, diethyl carbonate, etc.), lactones (γ-butyrolactone, etc.), ethers (1) a chain ether of 2-dimethoxyethane, dimethyl ether or diethyl ether; tetrahydrofuran, 2-methyltetrahydrofuran, dioxolan, 4-methyldioxoalkane, etc. Cyclic ethers), Sulfolane (cyclobutylene, etc.), fluorene (dimethyl hydrazine, etc.), decylamine (N,N-dimethylformamide, N,N) - dimethylacetamide, etc.), water, and the like. The solvent may be used alone or in combination of two or more.

Also as described above, when adjusting the pH of the ionic polymer, The pH of the ionic polymer can be adjusted to the same range as described above even in the photoelectric conversion element. From the viewpoint of such pH adjustment, components of the electrolytic solution may be appropriately used as components which do not affect the pH adjustment. For example, a neutral solvent or a non-acid solvent (or an aprotic solvent) may be suitably used as the electrolyte.

Also, the concentration of the electrolyte in the electrolyte may be, for example, 0.01. ~10M, preferably 0.03~8M, and more preferably about 0.05~5M. Further, when a halogen (iodine or the like) and a halide salt (such as an iodide salt) are combined, the ratio may be a halogen/halide salt (mole ratio) = 1/0.5 to 1/100, preferably 1/. 1~1/50, and more preferably 1/2~1/30.

Also as an electrolyte of the solid layer, in addition to the electricity exemplified above In addition to the cleavage, a solid electrolyte (for example, a resin component [for example, a thiophene-based polymer (for example, polythiophene) or a carbazole-based polymer (for example, poly(N-vinylcarbazole)), etc.] can be cited. Molecular organic components (such as naphthalene, anthracene, anthocyanins) An organic solid component such as celite or the like; an inorganic solid component such as silver iodide or the like}. These components may be used alone or in combination of two or more.

Also, the solid layer may be the electrolyte and the electrolyte It is stored in a solid layer of a colloidal substrate [for example, a thermoplastic resin (such as polyethylene glycol or polymethyl methacrylate) or a thermosetting resin (such as epoxy resin).

The photoelectric conversion elements of the structures are single elements and It is capable of absorbing a wide wavelength range from a short wavelength range to a long wavelength range and efficiently performing photoelectric conversion, and is suitable as a solar cell. Further, compared with a series-type photoelectric conversion element in which a plurality of elements are mounted, the photoelectric conversion efficiency can be improved with a very simple structure. In addition, since the electrode substrate, the electrolytic solution, and the like are not interposed between the photoelectric conversion layers having different absorption wavelengths, the loss of light absorption is small, and parts such as a high-priced conductive substrate can be reduced, and the photoelectric conversion element can be manufactured at low cost.

[Examples]

Hereinafter, the present invention will be described in more detail based on the examples, but the present invention is not limited by the examples.

[Example 1]

The anionic polymer (5 wt% perfluorosulfonic acid dispersion ("nafion DE520", ion exchange capacity 0.9 meq/g, pH (25 ° C) = 1 per molecule) was diluted 2 times with isopropyl alcohol. The occupied area was about 0.024 nm ² )), and then neutralized with a 5% by weight aqueous lithium hydroxide solution (prepared by dissolving lithium hydroxide (manufactured by Tokyo Chemical Industry Co., Ltd.) in ion-exchanged water) to prepare 2.5% by weight of pH 7. Fluorosulfonic acid dispersion.

0.9 parts by weight of "N719" dye (manufactured by Solaronix Co., Ltd., molecular weight 1188.57, occupied area of about 1 nm ² per molecule) was added and dissolved in 200 parts by weight of the 2.5% by weight perfluorosulfonic acid dispersion, and 30 parts by weight of oxidation was added thereto. Titanium particles (manufactured by Japan AEROSIL Co., Ltd., "P25", an average primary particle diameter of 30 nm, a specific surface area of about 40 m ² /g, anatase/rutile type = 80/20 (by weight) mixture) and mixed to prepare Photoelectric conversion ink 1 (printing ink for short wavelength absorption).

The photoelectric conversion ink 2 (long-wavelength absorption ink) was prepared in the same manner as described above except that the "N749" dye (manufactured by Solaronix Co., Ltd., molecular weight 1188.57, and the occupied area per molecule was about 1 nm ² ) was used instead of the "N719" dye.

The obtained photoelectric conversion ink 1 is coated by a doctor blade method After being placed on the side of the ITO layer of a glass substrate (manufactured by GEOMATEC, size: 12 mm × 25 mm, surface resistance: 10 Ω/□), the film was dried at 90 ° C in the air to form a photoelectric conversion layer 1 (short wavelength absorption layer). Then, the photoelectric conversion ink 2 is applied onto the photoelectric conversion layer 1 by a doctor blade method, and then dried at 90 ° C in the atmosphere to form a photoelectric conversion layer 2 (long wavelength absorption layer). The laminated photoelectric conversion layer was cut into a predetermined size (4 mm × 4 mm) and the additional thin film was removed to form a laminated photoelectric conversion having a thickness of 10 μm (the thickness of the photoelectric conversion layer 1 was 6 μm, and the thickness of the photoelectric conversion layer 2 was 4 μm). Floor.

As a counter electrode with respect to the laminated photoelectric conversion layer, A platinum film (electrode) having a thickness of 0.003 μm was formed by an ITO layer of a glass substrate (10 Ω/□ manufactured by GEOMATEC Co., Ltd.) to which ITO was attached by sputtering.

Separating partitions around the two glass substrates (Mitsui ‧ DuPont Poly Chemical Co., Ltd., "HIMILAN"), the photoelectric conversion layer side of the laminated photoelectric conversion layer and the counter platinum film are opposed to each other and the electrolyte A dye-sensitized solar cell is prepared by filling the gap formed between the two electrodes (or a space sealed by the sealing material) with an epoxy resin to seal the electrolyte injection port. Further, an electrolyte solution was used in an acetonitrile solution containing 0.05 M iodine, 0.1 M lithium iodide, 0.5 M 1,2-dimethyl-3-propylimidazolium iodide, and 0.5 M 4-tetrabutylpyridine.

[Comparative Example 1]

The photoelectric conversion ink 1 ("N719" dye, short-wavelength absorption) prepared in Example 1 was applied onto the ITO layer side of the ITO-attached glass substrate by a doctor blade method, and then dried at 90 ° C in the air. A photoelectric conversion layer 1 (short wavelength absorption layer) was formed, and the photoelectric conversion layer was cut in the same manner as in Example 1 to obtain a dye-sensitized solar cell having a photoelectric conversion layer having a thickness of 10 μm (the thickness of the photoelectric conversion layer 1 of 10 μm).

[Comparative Example 2]

A dye-sensitized solar cell was produced in the same manner as in Comparative Example 1, except that the photoelectric conversion ink 2 ("N749" dye, long-wavelength absorption) prepared in Example 1 was used instead of the photoelectric conversion ink 1 of Comparative Example 1. .

[Embodiment 2]

In the same manner as in Example 1, except that the N719 dye was replaced with MK-2 dye (manufactured by Soken Chemical Co., Ltd.) in Example 1, and the thickness of the photoelectric conversion layer 1 was 3 μm and the thickness of the photoelectric conversion layer 2 was 7 μm. Make dye-sensitized solar cells.

The examples 1 and 2 and the comparative example 1 were evaluated under the conditions of AM 1.5, 100 mW/cm ² , and 25 ° C using a solar simulator ("XES-301S+EL-100" manufactured by Sanyo Electric Co., Ltd.). 2 obtained dye sensitized solar cells. Figure 1 shows the output characteristics of the dye-sensitized solar cell obtained.

As is apparent from Fig. 1, when a build-up type photoelectric conversion layer is formed, the photoelectric conversion efficiency can be greatly improved.

[Example 3]

In addition to the use of the ITO-attached polyethylene terephthalate (PET) film (manufactured by Aldrich Co., Ltd., size 30×50 mm, thickness of the ITO layer: 0.12 μm) in place of the ITO-attached glass substrate, A dye-sensitized solar cell was produced in the same manner as in Example 1, and the same output characteristics as in Example 1 were obtained.

[Industrial availability]

The laminated photoelectric conversion body (laminate) of the present invention has a multilayer photoelectric conversion layer having different absorption wavelengths, and is advantageous for forming a photoelectric conversion element (dye sensitized solar cell or the like). Further, since the laminated photoelectric converter (laminate) can be formed by coating without sintering, it is easy to form a photoelectric conversion layer or a photoelectric conversion element.

Claims (9)

A laminated photoelectric converter comprising a laminated photoelectric converter comprising a semiconductor and an ionic polymer and a photoelectric conversion layer of a dye, wherein the laminated photoelectric conversion system is formed by laminating a plurality of layers of the photoelectric conversion layer, and each photoelectric The dye contained in the conversion layer has a different absorption wavelength range or absorption peak wavelength. The laminated photoelectric converter of claim 1, wherein a photoelectric conversion layer containing a dye capable of absorbing a short wavelength range is formed on the light receiving side, and a photoelectric conversion layer containing a dye capable of absorbing a long wavelength range is formed on the penetration side. The multilayer photoelectric conversion body according to claim 1 or 2, wherein the photoelectric conversion layer on the light-receiving side contains the first dye having an absorption peak wavelength of 300 to 600 nm, and the opposite side of the light receiving side The photoelectric conversion layer contains a second dye having an absorption peak wavelength of 550 to 800 nm, and the absorption peak wavelength of the first dye is a shorter wavelength shorter than the absorption peak wavelength of the second dye by 10 nm or more. The laminated photoelectric converter according to any one of claims 1 to 3, wherein the semiconductor comprises at least one selected from the group consisting of titanium oxide nanoparticles, and zinc oxide nanoparticles, tin oxide nanoparticles, and the ionic polymer comprises sulphur The fluorine-containing resin is based on, and the ratio of the ionic polymer is from 1 to 100 parts by weight based on 100 parts by weight of the semiconductor. A combination of a plurality of coating compositions comprising a semiconductor, an ionic polymer, and a dye, and a combination of coating compositions for forming a multilayer photoelectric conversion layer on a conductive substrate, wherein the plurality of coating compositions individually have mutual Dyes that do not share the same wavelength range or absorb the peak wavelength. A method for producing a laminated photoelectric converter, wherein a coating composition comprising a semiconductor, an ionic polymer, and a dye is applied to a conductive substrate to form a photoelectric conversion layer, and a dye contained in each coating agent The absorption wavelength range or the absorption peak wavelength is different from each other, and the plurality of coating compositions are sequentially coated and laminated on the conductive substrate without sintering. A photoelectric conversion element comprising the laminated photoelectric converter according to any one of claims 1 to 4. The photoelectric conversion element according to claim 7, comprising a laminated photoelectric converter according to any one of claims 1 to 4 formed as an electrode on the conductive substrate, a counter electrode disposed opposite to the electrode, and a sealing member The electrolyte phase between the electrodes. A method for producing a photoelectric conversion element, comprising: a photoelectric conversion layer formed on a conductive substrate as an electrode; a counter electrode disposed opposite to the electrode; and a photoelectric conversion element sealed to an electrolyte phase between the electrodes a manufacturing method comprising sequentially coating and laminating a plurality of coating compositions comprising a semiconductor, an ionic polymer, and a dye, and a dye having a different absorption wavelength range or absorption peak wavelength of each of the coating agents, and laminating on the conductive substrate And a step of forming a laminated photoelectric conversion body in which the multilayered photoelectric conversion layer has been laminated without performing sintering.