JP2021057497A - Dye-sensitization type solar cell and manufacturing method thereof, and solar cell module - Google Patents

Abstract

To provide a dye-sensitization type solar cell with high photoelectric conversion efficiency and manufacturing method thereof, and to provide a solar cell module with high photoelectric conversion efficiency.SOLUTION: A dye-sensitization type solar cell 1 having a photonic crystal layer 5 is provided between a photoelectrode 2 including a porous semiconductor layer 221 and an electrolyte layer 3. The porous semiconductor layer 221 uses a semiconductor constituent A as a major component and the photonic crystal layer 5 uses a constituent B different from the semiconductor constituent A.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dye-sensitized solar cell, a method for manufacturing the same, and a solar cell module.

In recent years, solar cells have been attracting attention as photoelectric conversion elements that convert light energy into electric power. Among them, dye-sensitized solar cells can be expected to be lighter than silicon-type solar cells, can generate stable power over a wide illuminance range, and are relatively inexpensive without the need for large-scale equipment. It is attracting attention because it can be manufactured using materials.

Here, the dye-sensitized solar cell usually has a structure in which a photoelectrode including a porous semiconductor layer on which a sensitizing dye is adsorbed, an electrolyte, and a counter electrode having a catalyst layer are arranged in this order.

Then, for example, Patent Document 1 has a laminated structure in which fine particle layers composed of a plurality of regularly arranged fine particles (silica with an average particle diameter D = 280 nm, SiO _{x) are laminated in a photoelectric conversion layer.} A photoelectric conversion element having a photonic crystal and having semiconductor fine particles (titania) as a light absorber and a dye arranged in a gap between the fine particles is disclosed.

Japanese Unexamined Patent Publication No. 2006-24495

However, there is room for improvement in the above-mentioned conventional technique in terms of increasing the photoelectric conversion efficiency of the dye-sensitized solar cell.

Therefore, an object of the present invention is to provide a dye-sensitized solar cell having high photoelectric conversion efficiency and a method for manufacturing the same.
Another object of the present invention is to provide a solar cell module having high photoelectric conversion efficiency.

The present inventor has made diligent studies to solve the above problems. Then, the present inventor has found that a dye-sensitized solar cell having a photonic crystal layer between an optical electrode including a porous semiconductor layer and an electrolyte layer can increase the photoelectric conversion efficiency. The invention was completed.

That is, the present invention aims to advantageously solve the above problems, and the dye-sensitized solar cell of the present invention includes a photoelectrode including a porous semiconductor layer containing a semiconductor component A as a main component. A photonic crystal layer is provided between the photonic crystal layer and the semiconductor layer, and the photonic crystal layer contains a component B different from the semiconductor component A as a main component. As described above, a photonic crystal layer is provided between the photoelectrode including the porous semiconductor layer containing the semiconductor component A as a main component and the electrolyte layer, and the photonic crystal layer is a component different from the semiconductor component A. If B is the main component, the photoelectric conversion efficiency of the dye-sensitized solar cell can be improved.

Here, in the dye-sensitized solar cell of the present invention, the thickness of the photonic crystal layer is preferably 0.05 μm or more, more preferably 0.2 μm or more, and preferably 6 μm or less. , 1.5 μm or less is more preferable. When the thickness of the photonic crystal layer is 0.05 μm or more and 6 μm or less, the photoelectric conversion efficiency of the dye-sensitized solar cell can be improved. The thickness of one photonic crystal layer roughly corresponds to the particle size (depending on the material). Therefore, the number of layers of the photonic crystal layer can be estimated from the thickness of the photonic crystal layer.

Further, in the dye-sensitized solar cell of the present invention, it is preferable that the photonic crystal layer is a fine particle layer in which a plurality of fine particles are regularly arranged. By forming the photonic crystal layer into a fine particle layer in which a plurality of fine particles are regularly arranged, high photoelectric conversion efficiency can be maintained satisfactorily.

In the dye-sensitized solar cell of the present invention, the fine particle layer preferably contains at least silicon dioxide fine particles. A good photonic crystal layer can be obtained by forming a fine particle layer containing at least silicon dioxide fine particles.

The present invention also aims to advantageously solve the above problems, and the method for producing a dye-sensitized solar cell of the present invention uses the fine particle dispersion liquid containing the plurality of fine particles to obtain the photonic crystal. It is characterized by including a photonic crystal layer forming step of forming a nick crystal layer. A photonic crystal layer can be efficiently formed by using a fine particle dispersion liquid containing a plurality of fine particles, and as a result, the production efficiency of a dye-sensitized solar cell is improved.

Furthermore, the present invention aims to solve the above problems advantageously, and the solar cell module of the present invention is characterized by including any of the above-mentioned dye-sensitized solar cells. According to the present invention, it is possible to provide a solar cell module having high photoelectric conversion efficiency.

According to the present invention, it is possible to provide a dye-sensitized solar cell having high photoelectric conversion efficiency and a method for manufacturing the same.
Further, according to the present invention, it is possible to provide a solar cell module having high photoelectric conversion efficiency.

It is a figure which shows the schematic structure of the dye-sensitized solar cell which concerns on one Embodiment of this invention. It is a figure which shows the schematic structure of the dye-sensitized solar cell which concerns on other embodiment of this invention.

Hereinafter, one embodiment of the present invention will be described in detail by dividing it into 1) a dye-sensitized solar cell, 2) a method for manufacturing a dye-sensitized solar cell, and 3) a solar cell module.

1) Dye-sensitized solar cell The dye-sensitized solar cell 1 shown in FIG. 1 has a structure in which a photoelectrode 2, an electrolyte layer 3, and a counter electrode 4 are arranged in this order, and the photoelectrode 2 and the electrolyte layer 3 are arranged in this order. It has a photonic crystal layer 5 between and.

The photoelectrode 2 has a photoelectrode substrate 21 and a photoelectric conversion layer 22.

The photoelectrode substrate 21 includes a support 211 and a conductive film 212. The photoelectrode substrate 21 plays a role of supporting the photoelectric conversion layer 22 and the like and a role as a current collector.

As the support 211, a conductive sheet formed of a metal, a metal oxide, a carbon material, a conductive polymer, or the like, or a non-conductive sheet made of resin, glass, or the like is used. Among them, from the viewpoint of providing the dye-sensitized solar cell 1 which is lightweight and has excellent photoelectric conversion efficiency, the support 211 is preferably a non-conductive sheet, and more preferably a transparent resin sheet. ..

Examples of the transparent resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), polyphenylene sulfide (PPS), polycarbonate (PC), polyarylate (PAr), polysulfone (PSF), and the like. Examples thereof include synthetic resins such as polyethersulfone (PES), polyetherimide (PEI), cycloolefin polymer (COP), and transparent polyimide (PI).

The thickness of the support 211 may be appropriately set, but is usually 10 μm or more and 10000 μm or less.

The conductive film 212 includes metals such as platinum, gold, silver, copper, aluminum, indium and titanium; conductive metal oxides such as tin oxide and zinc oxide; indium-tin oxide (ITO) and indium-zinc oxide. Examples thereof include composite metal oxides such as (IZO); carbon materials such as carbon nanotubes and fullerene; and combinations of two or more of these; and the like.

The thickness of the conductive film 212 may be appropriately set, but is usually 0.1 μm or more and 250 μm or less.

The surface resistance value of the conductive film 212 is preferably 500 Ω / □ or less, more preferably 150 Ω / □ or less, and further preferably 50 Ω / □ or less.

As a method for forming the conductive film 212 on the support 211, a known forming method such as a method combining sputtering and etching or screen printing can be used.

The photoelectric conversion layer 22 includes a porous semiconductor layer 221 and a sensitizing dye 222.

The porous semiconductor layer 221 is a layer containing the semiconductor component A as a main component. Since the porous semiconductor layer 221 is porous, the amount of adsorption of the sensitizing dye 222 is increased, and the photoelectric conversion efficiency can be made excellent. In the present invention, "having semiconductor component A as a main component" means that the porous semiconductor layer 221 contains 50% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more of semiconductor component A. Means.

The semiconductor component A is not particularly limited, and is, for example, various metal oxide semiconductors such as titanium oxide, zirconium oxide, zinc oxide, vanadium oxide, niobium oxide, tantalum oxide, and tungsten oxide, strontium titanate, and calcium titanate. , Various composite metal oxide semiconductors such as magnesium titanate, barium titanate, potassium niobate, transition metal oxides such as magnesium oxide, strontium oxide, aluminum oxide, cobalt oxide, nickel oxide, manganese oxide, cerium oxide, gadolinium oxide , Lantanoid oxides such as samarium oxide and itterbium oxide, and natural or synthetic silicic acid compounds typified by silica. The components other than the semiconductor component A that can be contained in the porous semiconductor layer 221 are not particularly limited as long as they can maintain the porosity of the porous semiconductor layer 221 well.

The porous semiconductor layer 221 is preferably a layer composed of a plurality of semiconductor fine particles. Examples of the semiconductor fine particles include fine particles composed of the semiconductor component A.

The volume average particle size of the semiconductor fine particles can be appropriately adjusted within a range in which the desired effect of the present invention can be obtained.

The thickness of the porous semiconductor layer 221 is not particularly limited, but is usually 0.1 μm or more, preferably 5 μm or more, and usually 50 μm or less, preferably 30 μm or less.

The porous semiconductor layer 221 can be formed by a known method such as a press method, a hydrothermal decomposition method, an electrophoretic electrodeposition method, a coating method, and a binder-free coating method.

The sensitizing dye 222 is a compound that can be excited by light to transfer electrons to the porous semiconductor layer 221 and is adsorbed on the surface of the porous semiconductor layer 221.

Examples of the sensitizing dye 222 include organic dyes such as cyanine dye, merocyanine dye, oxonor dye, xanthene dye, squarylium dye, polymethine dye, coumarin dye, riboflavin dye, and perylene dye; Metal complex dyes such as porphyrin complexes; and the like.

The method of adsorbing the sensitizing dye 222 on the porous semiconductor layer 221 is not particularly limited, and examples thereof include a method of immersing the photoelectrode 2 containing the porous semiconductor layer 221 in a dye solution containing the sensitizing dye 222. Be done.

The photonic crystal layer 5 has a periodic refractive index distribution and contains a component B different from the semiconductor component A contained in the porous semiconductor layer 221 as a main component. In the present invention, "having component B as a main component" means that the photonic crystal layer 5 contains 50% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more of component B. To do.

The component B, is not particularly limited, for example, silicon dioxide, aluminum oxide, tantalum oxide, gadolinium oxide, yttrium oxide, Pb (Zr, Ti) O 3 and the like. Further, as the component B, the same component as the semiconductor component A described above may be applied.

The photonic crystal layer 5 is preferably a fine particle layer in which a plurality of fine particles are regularly arranged. The fine particles contained in the fine particle layer are not particularly limited, and examples thereof include fine particles composed of component B.

Here, from the viewpoint of further improving the photoelectric conversion efficiency of the dye-sensitized solar cell 1, the particle size of the fine particles is preferably 50 nm or more and 1 μm or less.

The thickness of the photonic crystal layer 5 is usually 0.05 μm or more and 6 μm or less. When the thickness of the photonic crystal layer 5 is within the above range, the adhesion between the photoelectrode 2 and the photonic crystal layer 5 is excellent, and the performance of the dye-sensitized solar cell 1 can be kept good. ..

The method for forming the photonic crystal layer 5 is not particularly limited, but from the viewpoint of improving the production efficiency of the dye-sensitized solar cell 1, it is preferable to form the photonic crystal layer 5 by using the fine particle dispersion liquid containing the above-mentioned fine particles. From the viewpoint of facilitating the preparation of the fine particle dispersion, it is preferable to use silicon dioxide as the fine particles. The method for forming the photonic crystal layer 5 using the fine particle dispersion liquid will be specifically described in the section of the method for manufacturing a dye-sensitized solar cell.

The electrolyte layer 3 is a layer for separating the photoelectrode 2 and the counter electrode 4 and efficiently transferring charges. The electrolyte layer 3 usually contains a supporting electrolyte, a redox pair (a pair of chemical species that can be reversibly converted to each other in the form of an oxidant and a reduced compound in the redox reaction), a solvent and the like.

Examples of the supporting electrolyte include salts containing cations such as lithium ion, imidazolium ion, and quaternary ammonium ion.

As the redox pair, any known one can be used as long as it can reduce the oxidized sensitizing dye. Specifically, as redox pairs, chlorine compound-chlorine, iodine compound-iodine, bromine compound-bromine, tarium ion (III) -talium ion (I), ruthenium ion (III) -ruthenium ion (II), Copper ion (II) -copper ion (I), iron ion (III) -iron ion (II), cobalt ion (III) -cobalt ion (II), vanadium ion (III) -vanadium ion (II), manganese acid Examples thereof include ion-permanganate ion, ferricyanide-ferrocyanide, quinone-hydroquinone, fumaric acid-succinic acid and the like.

As the solvent, a solvent known as a solvent used for forming the electrolyte layer of the dye-sensitized solar cell can be used. Specific examples of the solvent include acetonitrile, methoxyacetonitrile, methoxypropionitrile, N, N-dimethylformamide, ethylmethylimidazolium bistrifluoromethylsulfonylimide, propylene carbonate and the like.

The electrolyte layer 3 can be formed, for example, by preparing a cell having a photoelectrode 2 and a counter electrode 4 with a solution (electrolyte solution) containing the constituent components, and injecting the electrolytic solution into the gap thereof.

The counter electrode 4 is composed of a conductive film 42 formed on the support 41 and a catalyst layer 43 formed on the conductive film 42.

The support 41 can be, for example, the same as the support 211. Further, the conductive film 42 can be the same as the conductive film 212, for example. When the conductive film 42 is made of carbon nanotubes, the conductive film 42 can also serve as the catalyst layer 43, and the catalyst layer 43 can be omitted.

The catalyst layer 43 functions as a catalyst when electrons are transferred from the counter electrode 4 to the electrolyte layer 3 in the dye-sensitized solar cell 1.

The catalyst layer 43 is not particularly limited, and is any catalyst containing a component that can function as a catalyst, such as a conductive polymer, carbon nanostructures, noble metal particles, and a mixture of carbon nanostructures and noble metal particles. Layers can be used.

Here, examples of the conductive polymer include poly (thiophene-2,5-diyl), poly (3-butylthiophene-2,5-diyl), and poly (3-hexylthiophen-2,5-diyl). , Poly (2,3-dihydrothieno- [3,4-b] -1,4-dioxin) (PEDOT) and other polythiophenes; polyacetylene and its derivatives; polyaniline and its derivatives; polypyrrole and its derivatives; poly (p-xylene) Tetrahydrothiophenium chloride), poly [(2-methoxy-5- (2'-ethylhexyloxy))-1,4-phenylene vinylene], poly [(2-methoxy-5- (3', 7'-) Polyphenylene vinylenes such as dimethyloctyloxy) -1,4-phenylene vinylene)], poly [2-2', 5'-bis (2'-ethylhexyloxy) phenyl] -1,4-phenylene vinylene], etc. Can be mentioned.
Examples of carbon nanostructures include natural graphite, activated carbon, artificial graphite, graphene, carbon nanotubes, and carbon nanobuds.
The noble metal particles are not particularly limited as long as they have a catalytic action, and known noble metal particles such as metallic platinum, metallic palladium, and metallic ruthenium can be appropriately selected and used.

The thickness of the catalyst layer 43 is not particularly limited, and can be, for example, 0.005 μm or more and 100 μm or less.

In the dye-sensitized solar cell 1 shown in FIG. 1, light energy is converted into electrical energy by repeating the following cycle. That is, (i) when the dye-sensitized solar cell 1 receives light, the light resonates in the in-plane direction of the photonic crystal layer 5. Further, the light received by the dye-sensitized solar cell 1 is diffracted or scattered as it passes through the photonic crystal layer 5. This increases the path of light passing through the photoelectric conversion layer 22. In other words, the light absorption rate in the photoelectric conversion layer 22 increases. (Ii) Then, when the sensitizing dye 222 is excited by receiving the light absorbed by the photoelectric conversion layer 22, the electrons (not shown) of the sensitizing dye 222 are taken out. (Iii) The electrons exit from the photoelectrode 2, move to the counter electrode 4 through the external circuit 10, and further move to the electrolyte layer 3 via the catalyst layer 43. In FIG. 1, the arrows indicate the movements of electrons. (Iv) Then, the redox pair (reducing agent) contained in the electrolyte layer 3 reduces the sensitizing dye 222 in the oxidized state, regenerates the sensitizing dye 222, and returns to a state in which light can be absorbed again. Therefore, according to the dye-sensitized solar cell 1, the electromotive force amount can be increased and the photoelectric conversion efficiency can be increased.

The dye-sensitized solar cell of the present invention is not limited to the configuration shown in FIG. 1, and in addition to the photoelectrode, photonic crystal layer, electrolyte layer, and counter electrode, for example, a protective layer, an antireflection layer, and the like. It may further have a gas barrier layer or the like.

Further, the dye-sensitized solar cell of the present invention is not limited to the one using the sun as a light source, and may be, for example, one using indoor lighting as a light source.

2) Method for manufacturing a dye-sensitized solar cell The method for manufacturing a dye-sensitized solar cell of the present invention is not particularly limited, and for example, it can be manufactured by the method shown below.

The method for manufacturing the dye-sensitized solar cell of the present invention will be described again with reference to FIG. The method for producing the dye-sensitized solar cell 1 needs to include a photonic crystal layer forming step of forming the photonic crystal layer 5 using a fine particle dispersion, and optionally other than the photonic crystal layer forming step. Other steps may be included. Here, as another step, for example, an adsorption step of adsorbing the sensitizing dye 222 on the surface of the porous semiconductor layer 221 can be mentioned.

Hereinafter, the first to fourth embodiments of the method for manufacturing a dye-sensitized solar cell of the present invention will be specifically described.

(First Embodiment)
<Photonic crystal layer forming process>
In the photonic crystal layer forming step, the photonic crystal layer 5 is formed on the surface of the porous semiconductor layer 221 using the fine particle dispersion liquid.

[Particulate dispersion]
As the fine particle dispersion, a dispersion containing fine particles described in the section of the dye-sensitized solar cell may be used. Examples of the fine particle dispersion include a silicon dioxide fine particle dispersion containing silicon dioxide fine particles, a mixed fine particle dispersion containing silicon dioxide fine particles and titanium oxide fine particles, and the like. Further, when water is used as a solvent in the preparation of the fine particle dispersion liquid described below, the fine particles contained in the fine particle dispersion liquid preferably have a silanol group, a hydroxyl group or the like. When the fine particles have these functional groups, the dispersibility of the fine particles in water as a solvent is improved.

− Solvent −
As the solvent used for preparing the fine particle dispersion, water; alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, dioxane and jigglime; N, N-dimethylformamide. , N, N-Dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and other amides; sulfur-containing solvents such as dimethyl sulfoxide and sulfolane: etc. Is preferable. These solvents can be used alone or in combination of two or more.

− Monodispersity −
The monodispersity of the fine particle dispersion is preferably 10% or less, and more preferably 5% or less. When the monodispersity of the fine particle dispersion is 10% or less, it becomes easy to arrange the fine particles regularly, and as a result, the formation of the photonic crystal layer 5 becomes easy.

Here, the "single dispersion degree" is represented by the following formula (I).
Monodispersity = (standard deviation of particle size of fine particles) x 100 / (average value of particle size of fine particles) ... (I)

− Concentration −
The concentration of the fine particles in the fine particle dispersion is not particularly limited, but is preferably 5% by mass or more and 20% by mass or less. When the concentration of the fine particles in the fine particle dispersion is within the above range, the formation of the photonic crystal layer 5 becomes easier.

Here, the formation of the photonic crystal layer 5 will be described with reference to FIG. In FIG. 2, the same members as those shown in FIG. 1 are assigned the same numbers, and the description thereof will be omitted.
Specifically, the photonic crystal layer 5 is formed by utilizing a self-assembling reaction using a fine particle dispersion liquid. Here, the self-organization refers to a phenomenon in which the fine particles form a specific ordered structure due to the interaction between the fine particles contained in the fine particle dispersion. For example, when the fine particle dispersion is dropped onto the porous semiconductor layer 221, the fine particles contained in the fine particle dispersion undergo a self-assembling reaction, and a plurality of fine particles are regularly arranged on the porous semiconductor layer 221. It forms a specific structure. Therefore, if the coating film is dried after dropping the fine particle dispersion liquid, a desired photonic crystal layer 5 can be formed on the porous semiconductor layer 221. At that time, the method for drying the coating film is not particularly limited, but the surface of the porous semiconductor layer 221 coated with the fine particle dispersion liquid is not maintained so as to be perpendicular to the mounting table of the photoelectrode substrate 21. It is preferably dried (vertical precipitation method). As a result, the photonic crystal layer 5 can be formed on the porous semiconductor layer 221 as a regular array of the single layers (single layer array) shown in FIG. By further repeating the above operation, a plurality of photonic crystal layers 5 are formed, for example, as a structure in which single-layer arrays as shown in FIG. 1 are laminated (laminated array) according to the number of operations. Therefore, the number of layers can be controlled. The photonic crystal layer 5 thus formed can have a substantially close-packed structure such as a hexagonal close-packed structure. The number of photonic crystal layers 5 is preferably 20 or less. When the number of layers of the photonic crystal layer 5 is 20 or less, the adhesion to the porous semiconductor layer 221 is kept good and the performance is maintained, which is preferable. Further, when the number of layers of the photonic crystal layer 5 is 2 or more and 10 or less, the photoelectric conversion performance is further improved.

<Adsorption process>
In the adsorption step, the sensitizing dye 222 is adsorbed on the surface of the porous semiconductor layer 221. Examples of the method of adsorbing the sensitizing dye 222 include a method of immersing the porous semiconductor layer 221 having the photonic crystal layer 5 formed on the surface in the dye solution.

-Dye solvent-
The dye solvent contains a sensitizing dye 222 and a solvent, and may optionally contain an additive other than the sensitizing dye 222.

Solvents used for the dye solvent include, for example, glycol ethers such as ethylene glycol and propylene glycol; glycol esters; polyglycols; and water, and mixtures thereof, and ethanol, propanol, butanol, acetonitrile. , Dimethylformamide, and a mixed solvent with dimethyl sulfoxide and the like can be used.

The concentration of the sensitizing dye in the dye solution is not particularly limited, but the concentration of the sensitizing dye is preferably less than 4 mM.

Moreover, as an arbitrary additive, a thickener, a filler, a surfactant and the like can be mentioned.

Then, a cell (not shown) having the photoelectrode 2 on which the photonic crystal layer 5 is formed and the counter electrode 4 is prepared, and an electrolytic solution is injected into the gap by a known method to form an electrolyte layer. 3 can be formed to obtain a dye-sensitized solar cell 1. After the dye adsorption step described above, the photoelectrode 2 on which the photonic crystal layer 5 is formed may be fired, if necessary.

(Second embodiment)
In the first embodiment, a method of adsorbing the sensitizing dye 222 on the porous semiconductor layer 221 after forming the photonic crystal layer 5 has been described, but the method is not limited to this, and the second embodiment is porous. After forming the semiconductor layer 221, the sensitizing dye 222 may be adsorbed on the porous semiconductor layer 221 and then the photonic crystal layer 5 may be formed. At that time, the dye adsorption can be performed, for example, by immersing the porous semiconductor layer 221 in the dye solution described above.

(Third Embodiment)
Further, as the third embodiment, a dispersion liquid containing resin fine particles (resin fine particle dispersion liquid) may be used instead of the above-mentioned fine particle dispersion liquid. Then, for example, the resin fine particle dispersion liquid is dropped onto the porous semiconductor layer 221, and further the accumulated component-containing liquid that can be accumulated around the resin fine particles is further dropped, so that the accumulated components are further dropped around the regularly arranged resin fine particles. A structure that is clogged with particles is created. Then, after the coating film is dried, it is heated to burn out the resin fine particles, so that the spherical space in which the resin fine particles are arranged before the burning is regularly arranged, which is formed by being surrounded by the accumulated components. A crystal layer can be obtained. Here, the particle size of the resin fine particles is not particularly limited, and can be, for example, the same particle size as the fine particles contained in the fine particle dispersion, specifically 50 nm or more and 1 μm or less. The resin fine particles are not particularly limited, and for example, resin fine particles made of known resins such as polypropylene resin, polyphenylene ether resin, polyarylene sulfide resin, and polyether ketone resin can be used. Further, as the accumulating component-containing liquid that can be accumulated around the resin fine particles, a dispersion liquid of accumulable fine particles such as silica can be used, and in that case, the particle size of the fine particles used for accumulation is, for example, 1 nm or more. It can be 50 nm. Further, as the integrated component, an alkoxide, a sol, or the like that forms a structure by heating may be used.

(Fourth Embodiment)
Further, as a fourth embodiment, the photonic crystal layer 5 is formed not on the porous semiconductor layer 221 but on another substrate, and the obtained photonic crystal layer 5 is not adsorbed by the sensitizing dye 222. Alternatively, the photonic crystal layer 5 may be formed on the surface of the porous semiconductor layer 221 by transferring to the porous semiconductor layer 221 on which the sensitizing dye 222 is adsorbed. When the porous semiconductor layer 221 used does not have the sensitizing dye 222 adsorbed, the sensitizing dye 222 may be adsorbed after forming the photonic crystal layer 5.
When the photonic crystal layer 5 is formed on another substrate by using the resin fine particle dispersion liquid, the resin fine particles may be burnt by heating at a temperature of 500 to 600 ° C. for 3 to 4 hours, for example. it can. At this time, the heating method is not particularly limited.

3) Solar cell module The solar cell module of the present invention is formed by connecting a plurality of dye-sensitized solar cells of the present invention in series and / or in parallel. As the module structure, there are known structures such as Z type, W type, parallel type, current collector wiring type, and monolithic type.

In the solar cell module of the present invention, for example, the dye-sensitized solar cells of the present invention are arranged in a plane or curved shape, a non-conductive partition wall is provided between the batteries, and a photoelectrode or a counter electrode of each battery is provided. Can be obtained by electrically connecting using a conductive member. At that time, the number of dye-sensitized solar cells to be used is not particularly limited, and can be appropriately determined according to the target voltage.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the following description, "%" representing the amount is based on mass unless otherwise specified.
The evaluation of the battery performance and the confirmation of the photonic crystal layer were carried out by the following methods.

<Battery performance>
As a light source, a pseudo-sunlight irradiation device (PEC-L11 type, manufactured by Pexel Technologies Co., Ltd.) in which an AM1.5G filter was attached to a 150 W xenon lamp light source was used. The amount of light was adjusted to 1 sun (AM 1.5G, 100 mW / cm ² (JIS C 8912 class A). The dye-sensitized solar cell produced was connected to a source meter (2400 type source meter, manufactured by Keithley). The following current-voltage characteristics were measured.
Under 1 sun light irradiation, the output current was measured while changing the bias voltage from 0 V to 0.8 V in units of 0.01 V. The output current was measured by integrating the values from 0.05 seconds to 0.15 seconds after changing the voltage in each voltage step. A measurement was also performed in which the bias voltage was changed from 0.8 V to 0 V in the reverse direction, and the average value of the measurements in the forward direction and the reverse direction was taken as the photocurrent.
The open circuit voltage (V), the curve factor, and the photoelectric conversion efficiency (%) were calculated from the above measurement results of the current-voltage characteristics. Moreover, the short-circuit current density (mA / cm ² ) was measured.

<Confirmation of photonic crystal layer>
The confirmation of the photonic crystal layer was visually confirmed. Then, when the formed layer shines like a jewel beetle or a shell and the color changes depending on the angle, it is judged that the photonic crystal layer is surely formed.

(Example 1)
<Preparation of dye solution>
7.2 mg of ruthenium complex dye (N719, manufactured by Solaronics) was placed in a 20 mL volumetric flask. 10 mL of tert-butanol was added to the volumetric flask and stirred. Then, 8 mL of acetonitrile was added, the volumetric flask was plugged, and then the mixture was stirred for 60 minutes by vibration with an ultrasonic cleaner. Acetonitrile was added while keeping the solution at room temperature, and the total volume was adjusted to 20 mL to obtain a dye solution.

<Formation of porous semiconductor layer>
Low temperature filmed titanium oxide paste (manufactured by Pexel Technologies) on the ITO surface of a polyethylene naphthalate film (ITO-PEN film, film thickness 125 μm, sheet resistance 14 Ω / □) sputtered with indium-tin oxide (ITO). "PECC-C01-06") was applied using a baker-type applicator so that the thickness of the coating film was 100 μm. The obtained coating film was dried at room temperature for 10 minutes and then heated on a hot plate at 150 ° C. for another 10 minutes to obtain a laminate composed of an ITO-PEN film and a porous semiconductor layer.

<Formation of photonic crystal layer>
As the fine particle dispersion, silica fine particle aqueous dispersion I (silica fine particles: manufactured by Nippon Catalyst Co., Ltd., particle size 280 nm) adjusted to a concentration of 10% was used. According to the vertical precipitation method, the fine particle aqueous dispersion I was dropped onto the porous semiconductor layer of the laminate and dried to form one photonic crystal layer on the porous semiconductor layer.

<Adsorption of sensitizing dye>
The sensitizing dye was adsorbed on the porous semiconductor layer by immersing the laminate in the dye solution at 40 ° C. for 2 hours. After the immersion, the laminate was washed with acetonitrile and dried to obtain a photoelectrode.

<Manufacturing of counter electrode>
To a 30 mL glass container, add 5 g of water, 1 g of ethanol and 0.0025 g of carbon nanotubes (average diameter (Av): 3.3 nm, standard deviation of diameter (σ): 0.64 nm, 3σ / Av: 0.58). It was.
The contents of this glass container were subjected to a dispersion treatment for 2 hours using a bath-type ultrasonic cleaner (5510J-MT (42 kHz, 180 W) manufactured by BRANSON) to obtain an aqueous dispersion.
Water obtained as described above on the ITO surface of a polyethylene naphthalate film (ITO-PEN film, film thickness 200 μm, ITO thickness 200 nm, sheet resistance 15 Ω / □) sputtered with indium-tin oxide (ITO). The dispersion was applied using a bar coater (manufactured by Tester Sangyo Co., Ltd., SA-203, No. 10) so as to have a coating thickness of 22.9 μm. The obtained coating film was dried at 23 ° C. and 60% (relative humidity) for 2 hours to obtain a counter electrode.

<Preparation of electrolyte>
These are such that iodine is 0.05 mol / L, lithium iodide is 0.1 mol / L, t-butyl pyridine is 0.5 mol / L, and 1,2-dimethyl-3propylimidazolium iodide is 0.6 mol / L. Was dissolved in methoxyacetonitrile to obtain an electrolytic solution.

<Manufacturing dye-sensitized solar cells>
The inside of a heat-sealing film (manufactured by SOLARONIX) having a thickness of 25 μm was hollowed out in a circular shape having a diameter of 9 mm, and this film was set on a counter electrode. A dye-sensitized solar cell was produced by dropping an electrolytic solution, superimposing photoelectrodes from above, and sandwiching both sides with bagworm clips. Then, the battery performance was evaluated. The results are shown in Table 1.

(Example 2)
The step of forming the photonic crystal layer of Example 1 was repeated three times to form three photonic crystal layers on the porous semiconductor layer. A dye-sensitized solar cell was manufactured in the same manner as in Example 1 except for the above. Then, the battery performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
As the fine particle dispersion, instead of the silica fine particle water dispersion I, a silica fine particle water dispersion II (silica fine particles: manufactured by Nippon Catalyst Co., Ltd., particle size 510 nm) adjusted to a concentration of 10% was used to form a three-layer photonic crystal layer. Formed. A dye-sensitized solar cell was manufactured in the same manner as in Example 2 except for the above. Then, the battery performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 4)
Using the silica fine particle aqueous dispersion II used in Example 3, three more photonic crystal layers were further formed on the three photonic crystal layers formed in Example 2. A dye-sensitized solar cell was manufactured in the same manner as in Example 1 except for the above. Then, the battery performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 5)
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that 21 photonic crystal layers were formed on the porous semiconductor layer. Then, the battery performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that a photonic crystal layer was not formed. Then, the battery performance was evaluated in the same manner as in Example 1. The results are shown in Table 1.

From Examples 1 to 5 and Comparative Example 1 in Table 1, it can be seen that a dye-sensitized solar cell having high photoelectric conversion efficiency can be obtained by having the predetermined photonic crystal layer according to the present invention.

According to the present invention, it is possible to provide a dye-sensitized solar cell having high photoelectric conversion efficiency and a method for manufacturing the same.
Further, according to the present invention, it is possible to provide a solar cell module having high photoelectric conversion efficiency.

1 Dye-sensitized solar cell 2 Photoelectrode 3 Electrolyte layer 4 Opposite electrode 5 Photonic crystal layer 10 Circuit 21 Photoelectrode substrate 41 Support 42 Conductive 43 Catalyst layer 211 Support 212 Conductive 221 Porous semiconductor layer 222 Sensitization Pigment

Claims (6)

A photonic crystal layer is provided between the photoelectrode including the porous semiconductor layer containing the semiconductor component A as the main component and the electrolyte layer.
The photonic crystal layer is a dye-sensitized solar cell containing a component B different from the semiconductor component A as a main component. The dye-sensitized solar cell according to claim 1, wherein the photonic crystal layer has a thickness of 0.05 μm or more and 6 μm or less. The dye-sensitized solar cell according to claim 1 or 2, wherein the photonic crystal layer is a fine particle layer in which a plurality of fine particles are regularly arranged. The dye-sensitized solar cell according to claim 3, wherein the fine particle layer contains at least silicon dioxide fine particles. The dye-sensitized solar cell manufacturing method according to claim 3, further comprising a photonic crystal layer forming step of forming the photonic crystal layer using the fine particle dispersion liquid containing the plurality of fine particles. Manufacturing method of sensitive solar cells. A solar cell module comprising the dye-sensitized solar cell according to any one of claims 1 to 4.

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