JP5969844B2 - Dye-sensitized solar cell and method for producing the same - Google Patents

Description

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

  As a photoelectric conversion element, a dye-sensitized solar cell has attracted attention because it is inexpensive and high power generation efficiency can be obtained, and various developments have been made regarding the dye-sensitized solar cell.

  A dye-sensitized solar cell generally includes a transparent conductive substrate, a plurality of porous oxide semiconductor layers provided on the transparent conductive substrate, a photosensitizing dye supported on the porous oxide semiconductor layer, and a porous material. A counter electrode facing the oxide semiconductor layer; and an electrolyte provided between the transparent conductive substrate and the counter electrode.

  Thus, since the dye-sensitized solar cell carries the photosensitizing dye in the porous oxide semiconductor layer, a specific color is given to the light-receiving surface by giving different colors to the plurality of porous oxide semiconductor layers. It becomes possible to impart design properties such as a pattern of characters, symbols or figures.

  As a dye-sensitized solar cell imparted with such design properties, for example, a plurality of porous oxide semiconductor layers each having a different type of photosensitizing dye supported thereon are known (for example, See Patent Document 1 below).

JP 2010-9769 A

  However, the dye-sensitized solar cell described in Patent Document 1 has the following problems.

  In other words, the dye-sensitized solar cell described in Patent Document 1 can give excellent design properties, but there are cases where the photoelectric conversion characteristics deteriorate.

  The present invention has been made in view of the above circumstances, and provides a dye-sensitized solar cell and a method for manufacturing the same that can sufficiently suppress a decrease in photoelectric conversion characteristics even when excellent designability is imparted. The purpose is to do.

  The present inventor has examined the cause of the above problem in order to solve the above problem. In the dye-sensitized solar cell described in Patent Document 1, a different photosensitizing dye is supported on each of a plurality of porous oxide semiconductor layers. However, among these photosensitizing dyes, there are those that can impart design properties but cannot impart sufficient photoelectric conversion characteristics to the dye-sensitized solar cell. For this reason, this inventor thought that the photoelectric conversion characteristic of a dye-sensitized solar cell might fall as a whole. In particular, in a dye-sensitized solar cell, in order to impart excellent design properties, the number of porous oxide semiconductor layers provided on one transparent conductive substrate is increased, and different types of photosensitizing dyes are used. When supported, since there are limits to the types of photosensitizing dyes that can impart excellent photoelectric conversion characteristics, it is difficult to suppress a decrease in the overall photoelectric conversion characteristics of the dye-sensitized solar cell. Therefore, as a result of further intensive studies, the present inventor has found that the above-described problems can be solved by the following invention.

That is, the present invention provides a transparent conductive substrate, a plurality of porous oxide semiconductor portions that carry a photosensitizing dye and are provided on the transparent conductive substrate so as to be separated from each other, and the porous oxide semiconductor. A counter electrode provided opposite to the portion, an electrolyte disposed between the transparent conductive substrate and the counter electrode, and one provided among the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate. A ring-shaped adhesive that individually surrounds the remaining porous oxide semiconductor portions excluding the porous oxide semiconductor portion, and the type of the photosensitizing dye supported on the plurality of porous oxide semiconductor portions. The photosensitizing dyes include a common photosensitizing dye that is common to the plurality of porous oxide semiconductor portions, and the porous oxide semiconductor portion includes at least one porous oxide semiconductor layer. Consists of dye sensitization It is a solar cell.

  According to this dye-sensitized solar cell, since the photosensitizing dye contains a common photosensitizing dye in a plurality of porous oxide semiconductor parts, it has excellent photoelectric conversion characteristics as the common photosensitizing dye. If what can be imparted to the sensitized solar cell is used, it is possible to sufficiently suppress the deterioration of the photoelectric conversion characteristics of the dye-sensitized solar cell as a whole. In addition, since the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor portions is different from each other, it is possible to impart excellent design to the dye-sensitized solar cell. That is, according to the dye-sensitized solar cell of the present invention, it is possible to sufficiently suppress a decrease in photoelectric conversion characteristics of the entire dye-sensitized solar cell even when excellent designability is imparted.

  In the dye-sensitized solar cell, among the plurality of porous oxide semiconductor portions, in the porous oxide semiconductor portion in which a plurality of types of photosensitizing dyes are supported, a plurality of types of the photosensitizing dyes are mutually attached. It is preferable to have different absorption peak wavelengths.

  In this case, in the porous oxide semiconductor portion in which a plurality of types of photosensitizing dyes are supported, the plurality of types of photosensitizing dyes have different absorption peak wavelengths, so that the color of the porous oxide semiconductor portion Can be adjusted. In addition, since the wavelength region in which light can be sufficiently absorbed is wide, more excellent photoelectric conversion characteristics can be ensured as the entire dye-sensitized solar cell.

In the dye-sensitized solar cell, the electrolyte is, I ^- and I ₃ ^- comprises a redox couple consisting of, I ₃ in the electrolyte ^- the concentration of preferably not more than 0.006M.

When the concentration of I ₃ ⁻ is in the above range, photoelectric conversion characteristics can be further improved in a low illuminance environment such as indoors. In addition, I ₃ ^- concentration that is within the above range, the color of the electrolyte is sufficiently thin. As a result, the color due to the photosensitizing dye supported on the porous oxide semiconductor portion can be clearly recognized.

  In the dye-sensitized solar cell, the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate preferably have the same thickness from the transparent conductive substrate.

  In this case, in the dye-sensitized solar cell including each of the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate, the voltage can be made close to the value, and the porous oxide semiconductor portion is included. Since the power generation amount of each of the dye-sensitized solar cells is also close, even if the dye-sensitized solar cells including the porous oxide semiconductor portion are connected in series or in parallel, the overall power characteristics are not disturbed, When power is supplied to the external device, desired power can be accurately supplied.

  In the dye-sensitized solar cell, a coadsorbent is adsorbed on at least one porous oxide semiconductor portion of the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate. preferable.

  In this case, since the co-adsorbent does not develop color, if the co-adsorbent is adsorbed to at least one porous oxide semiconductor portion of the plurality of porous oxide semiconductor portions, the porous material to which the co-adsorbent is adsorbed The color in the oxide semiconductor portion can be reduced. As a result, it is possible to realize color shading as the entire dye-sensitized solar cell.

  The dye-sensitized solar cell further includes a sealing portion that connects the transparent conductive substrate and the counter electrode, and a colored inorganic sealing portion is provided between the sealing portion and the transparent conductive substrate. It is preferred that

  In this case, since the color can be visually recognized not only at the porous oxide semiconductor portion but also at the position of the inorganic sealing portion, more excellent design can be imparted.

The present invention also provides a porous oxide semiconductor part forming step of forming a plurality of porous oxide semiconductor parts on a transparent conductive substrate so as to be separated from each other , and one of the plurality of porous oxide semiconductor parts. The remaining porous oxide semiconductor portion excluding the porous oxide semiconductor portion is covered with a mask member to obtain a first structure, and then the first structure is converted into a first dye solution containing a photosensitizing dye. A first immersing step of immersing in the inside, and at least a part of the mask member is peeled off from one porous oxide semiconductor portion of the remaining porous oxide semiconductor portions covered with the mask member, After obtaining the structure, the second structure is immersed in a second dye solution containing a photosensitizing dye of a type different from the photosensitizing dye, and is supported on the plurality of porous oxide semiconductor portions. The number of different types of photosensitizing dyes 2 dipping step and a laminating step of laminating the transparent conductive substrate and the counter electrode so that an electrolyte is disposed between the transparent conductive substrate and the counter electrode, An annular adhesive composed of at least one porous oxide semiconductor layer, and the mask member is attached to the transparent conductive substrate so as to individually surround the porous oxide semiconductor portion; It is a manufacturing method of a dye-sensitized solar cell which has a cover member which covers the porous oxide semiconductor part with the adhesive . Alternatively, the present invention provides a porous oxide semiconductor portion forming step of forming a plurality of porous oxide semiconductor portions on a transparent conductive substrate so as to be separated from each other , and one of the plurality of porous oxide semiconductor portions. The remaining porous oxide semiconductor portion excluding the porous oxide semiconductor portion is covered with a mask member to obtain a first structure, and then the first structure is converted into a first dye solution containing a photosensitizing dye. A first immersing step of immersing in the inside, and at least a part of the mask member is peeled off from one porous oxide semiconductor portion of the remaining porous oxide semiconductor portions covered with the mask member, After obtaining the structure, the second immersing step of immersing the second structure in a second dye solution containing a photosensitizing dye of a type different from the photosensitizing dye, and the second immersing process are repeated. The plurality of porous oxide semiconductors A repeating step of making the number of types of photosensitizing dyes carried on the part different from each other, and the transparent conductive substrate and the counter electrode so that an electrolyte is disposed between the transparent conductive substrate and the counter electrode The porous oxide semiconductor part is composed of at least one porous oxide semiconductor layer, and the mask member is formed on the transparent conductive substrate with the porous oxidation substrate. It is a manufacturing method of a dye-sensitized solar cell which has the cyclic | annular adhesive agent affixed so that a physical semiconductor part may be enclosed individually, and the cover member which covers the said porous oxide semiconductor part with the said adhesive agent .

  According to the method for producing these dye-sensitized solar cells, in the obtained dye-sensitized solar cell, a common photosensitizing dye is supported on a plurality of porous oxide semiconductor parts. If a material capable of imparting excellent photoelectric conversion characteristics to the dye-sensitized solar cell is used, the deterioration of the photoelectric conversion characteristics of the entire dye-sensitized solar cell can be sufficiently suppressed. In addition, since the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor portions is different from each other, it is possible to impart excellent design to the dye-sensitized solar cell. That is, according to the method for producing a dye-sensitized solar cell of the present invention, it is possible to produce a dye-sensitized solar cell that can sufficiently suppress a decrease in photoelectric conversion characteristics even when excellent designability is imparted. Is possible. In addition, the appropriate immersion time of the photosensitizing dye usually varies depending on the type of the photosensitizing dye, but according to the above production method, the immersion time of each photosensitizing dye can be freely controlled. An appropriate immersion time can be ensured for each photosensitizing dye.

Further, according to the method for producing the dye-sensitized solar cell, the mask member is configured to have an annular adhesive and a cover member that covers the porous oxide semiconductor portion together with the adhesive, Since the adhesion between the cover member and the adhesive can be improved, the first dye solution and the second dye solution are sufficiently suppressed from entering the mask member in the first immersion process and the second immersion process. Is done. On the other hand, when removing the mask member, the porous oxide semiconductor portion can be easily exposed by simply removing the cover member.

  In the present invention, when the photosensitizing dye has a plurality of absorption peaks, the absorption peak wavelength of the photosensitizing dye is the wavelength of the absorption peak on the longest wavelength side among the absorption peak wavelengths. Shall be said.

  In the present invention, “the thickness of the plurality of porous oxide semiconductor portions from the transparent conductive substrate is the same” means that the porous oxide semiconductor portion having the largest thickness among the porous oxide semiconductor portions to be compared is used. The thickness of the porous oxide semiconductor portion is taken as a reference value, and the thickness of the porous oxide semiconductor portion from the transparent conductive substrate falls within the range of 10% with respect to this reference value.

  Furthermore, in the present invention, the thickness of the porous oxide semiconductor portion is the most of the plurality of porous oxide semiconductor layers when the porous oxide semiconductor portion is composed of a plurality of porous oxide semiconductor layers. The thickness of the porous oxide semiconductor layer having a large thickness shall be said.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where the outstanding design property is provided, the dye-sensitized solar cell which can fully suppress the fall of a photoelectric conversion characteristic, and its manufacturing method are provided.

It is sectional drawing which shows one Embodiment of the dye-sensitized solar cell which concerns on this invention. (A) And (b) is sectional drawing which shows a series of processes which form a some porous oxide semiconductor part on the transparent conductive substrate of FIG. (A)-(d) is sectional drawing which shows a series of processes which carry | support a photosensitizing dye to the several porous oxide semiconductor part of FIG. (A) is sectional drawing which shows the sealing part formation material crimping | compression-bonding process which crimps | bonds a sealing part formation material on the transparent conductive substrate of FIG.3 (d), (b) is several porous of (a). It is sectional drawing which shows the electrolyte arrangement | positioning process which arrange | positions electrolyte on an oxide semiconductor part. It is sectional drawing which shows other embodiment of the dye-sensitized solar cell which concerns on this invention. It is sectional drawing which shows other embodiment of the dye-sensitized solar cell which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings, the same or equivalent components are denoted by the same reference numerals, and redundant description is omitted.

<First Embodiment>
First, a first embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a first embodiment of a dye-sensitized solar cell according to the present invention.

  As shown in FIG. 1, a dye-sensitized solar cell 100 includes a transparent conductive substrate 10, two porous oxide semiconductor portions 20a and 20b provided on the transparent conductive substrate 10, and a porous oxide semiconductor portion. 20a, 20b is disposed between the counter electrode 30 provided opposite to the counter electrode 30, the annular sealing portion 40 connecting the transparent conductive substrate 10 and the counter electrode 30, and the porous oxide semiconductor portions 20a, 20b and the counter electrode 30. The electrolyte 50 is provided.

  The transparent conductive substrate 10 includes a transparent substrate 11 and a transparent conductive film 12 provided on the transparent substrate 11. The porous oxide semiconductor parts 20a and 20b carry a common photosensitizing dye, and the porous oxide semiconductor part 20a further includes a photosensitizing dye of a type different from the common photosensitizing dye. It is supported. Further, the porous oxide semiconductor portion 20 b is surrounded by an annular adhesive 60 fixed on the transparent conductive substrate 10.

  The counter electrode 30 includes a counter electrode substrate 31 and a catalyst layer 32 that is provided on the counter electrode substrate 31 on the porous oxide semiconductor portions 20a and 20b side and promotes a catalytic reaction.

  According to the dye-sensitized solar cell 100, since the common photosensitizing dye is supported on the porous oxide semiconductor portions 20a and 20b, the photoelectrically sensitive dye has excellent photoelectric conversion characteristics as the photosensitizing dye. If what can be imparted to the battery 100 is used, the deterioration of the photoelectric conversion characteristics of the dye-sensitized solar cell 100 as a whole can be sufficiently suppressed. In addition, since the number of types of photosensitizing dyes carried on the porous oxide semiconductor portions 20a and 20b is different from each other, it is possible to impart excellent design to the dye-sensitized solar cell 100. That is, according to the dye-sensitized solar cell 100, even if it is a case where the outstanding design property is provided, the fall of a photoelectric conversion characteristic can fully be suppressed.

  Next, the transparent conductive substrate 10, the porous oxide semiconductor portions 20a and 20b, the photosensitizing dye, the counter electrode 30, the sealing portion 40, and the electrolyte 50 will be described in detail.

(Transparent conductive substrate)
As described above, the transparent conductive substrate 10 includes the transparent substrate 11 and the transparent conductive film 12 provided thereon.

  The transparent substrate 11 is composed of a substrate made of a light transmissive material. Examples of such materials include glass, polyethylene terephthalate (PET), polycarbonate (PC), polyethersulfone (PES), polyethylene naphthalate (PEN), and are usually used as a transparent substrate for photoelectric conversion elements. Any material can be used. The transparent substrate 11 is appropriately selected from these in consideration of resistance to the electrolyte 50 and the like. Further, the transparent substrate 11 is preferably a base material excellent in light transmittance, and more preferably a base material having a light transmittance of 90% or more.

The transparent conductive film 12 is preferably a thin film made of a conductive metal oxide so that the transparency of the transparent conductive substrate 10 is not significantly impaired. Examples of such conductive metal oxides include indium tin oxide (ITO), fluorine-added tin oxide (FTO), and tin oxide (SnO ₂ ). Further, the transparent conductive film 12 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductive film 12 is composed of a single layer, the transparent conductive film 12 is preferably ITO or FTO from the viewpoint of easy film formation and low manufacturing cost, and high heat resistance and chemical resistance. From the viewpoint of having FTO, FTO is more preferable. The thickness of the transparent conductive film 12 may be in the range of 0.01 to 2 μm, for example.

(Porous oxide semiconductor part)
Each of the porous oxide semiconductor portions 20a and 20b may be composed of one porous oxide semiconductor layer, or may be composed of a plurality of porous oxide semiconductor layers separated from each other. The oxide semiconductor that forms the porous oxide semiconductor layer is not particularly limited, and any oxide semiconductor can be used as long as it is usually used to form a porous oxide semiconductor layer for a photoelectric conversion element. it can. Examples of such an oxide semiconductor include titanium oxide (TiO ₂ ), silica (SiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), and niobium oxide (Nb ₂ O). ₅ ), strontium titanate (SrTiO ₃ ) indium oxide (In ₃ O ₃ ), zirconium oxide (ZrO ₂ ), thallium oxide (Ta ₂ O ₅ ), lanthanum oxide (La ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), holmium oxide (Ho ₂ O ₃ ), bismuth oxide (Bi ₂ O ₃ ), cerium oxide (CeO ₂ ), and aluminum oxide (Al ₂ O ₃ ). These can be used alone or in combination of two or more.

  The average particle size of these oxide semiconductor particles is preferably 1 to 1000 nm because the surface area of the oxide semiconductor covered with the photosensitizing dye is increased and more electrons can be generated. The porous oxide semiconductor layer is preferably configured by stacking oxide semiconductor particles having different particle size distributions. In this case, light can be repeatedly reflected in the porous oxide semiconductor layer, and incident light that escapes to the outside of the porous oxide semiconductor layer can be reduced and light can be efficiently converted into electrons. it can.

  The thickness of the porous oxide semiconductor layer may be, for example, 0.5 to 50 μm. Note that the porous oxide semiconductor layer can also be formed of a stack of a plurality of oxide semiconductors made of different materials.

(Photosensitizing dye)
As a photosensitizing dye supported in common on the porous oxide semiconductor portions 20a and 20b (hereinafter referred to as “common photosensitizing dye”), a ruthenium complex containing a bipyridine structure, a terpyridine structure, or the like as a ligand, Examples thereof include metal-containing complexes such as porphyrin and phthalocyanine, and organic dyes such as eosin, rhodamine, and merocyanine. Among these, those exhibiting behavior suitable for the intended use and the semiconductor used can be selected without particular limitation. Specifically, N3, N719, N749, D131, D149, Z907, and the like can be used. Among them, N719, Z907, and the like are preferably used at low illuminance because they can impart excellent photoelectric conversion characteristics to the dye-sensitized solar cell 100.

  The photosensitizing dye other than the common photosensitizing dye supported on the porous oxide semiconductor portion 20a may be of a different type from the common photosensitizing dye, but has an absorption peak different from that of the common photosensitizing dye. It is preferable that it has a wavelength. In this case, in the porous oxide semiconductor portion 20a carrying two types of photosensitizing dyes, the two types of photosensitizing dyes have absorption peak wavelengths different from each other, so that the porous oxide semiconductor portion 20a. The color of can be adjusted. In addition, since the wavelength region capable of sufficiently absorbing light is wide, more excellent photoelectric conversion characteristics can be ensured as the entire dye-sensitized solar cell 100.

(Counter electrode)
The counter electrode substrate 31 is composed of, for example, a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, tungsten, or SUS, or a film formed of a conductive oxide such as ITO or FTO on the transparent substrate 11 described above. Is done. The thickness of the counter electrode substrate 31 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be, for example, 0.005 to 0.1 mm.

  The catalyst layer 32 is made of platinum, a carbon-based material, a conductive polymer, or the like.

  The thickness of the counter electrode 30 should just be in the range of 0.005-0.5 mm, for example.

(Sealing part)
As a material constituting the sealing portion 40, for example, an ionomer, an ethylene-vinyl acetate anhydride copolymer, an ethylene-methacrylic acid copolymer, a modified polyolefin such as an ethylene-vinyl alcohol copolymer, an ultraviolet curable resin, and A vinyl alcohol polymer is mentioned. In addition, the sealing part 40 may be comprised only with resin, and may be comprised with resin and an inorganic filler.

(Electrolytes)
The electrolyte 50 includes a redox couple such as I ⁻ and I ₃ ⁻ and an organic solvent. As an organic solvent, acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, valeronitrile, pivalonitrile, glutaronitrile, methacrylonitrile, isobutyronitrile, Phenylacetonitrile, acrylonitrile, succinonitrile, oxalonitrile, pentanitrile, adiponitrile and the like can be used.

The redox pair, such as I ^- and I ₃ ^- In addition to, bromine and bromide ion, zinc complex, an iron complex, and redox pairs such as cobalt complexes.

When I ⁻ and I ₃ ⁻ are used as the redox pair, the concentration of I ₃ ⁻ is preferably more than 0 and 0.006M or less.

When the concentration of I ₃ ⁻ is in the above range, photoelectric conversion characteristics can be further improved in a low illuminance environment such as indoors. In addition, I ₃ ^- concentration that is within the above range, the color of the electrolyte 50 is reduced. As a result, the color due to the photosensitizing dye carried on the porous oxide semiconductor portions 20a and 20b can be clearly seen.

The concentration of I ₃ ⁻ is more preferably 0.002M or less, and further preferably 6 × 10 ⁻⁶ M or less. In order to make the concentration of I ₃ ⁻ less than or equal to 6 × 10 ⁻⁶ M, it is only necessary to add I ₂ which is a source of I ₃ ⁻ . Even if I ₂ is not added, the concentration of I ₃ ⁻ can be reduced to 6 × 10 ⁻⁶ M or less as long as I ⁻ is present. The reason for this is not clear, but it is considered that I ⁻ reacts to produce I ₃ ⁻ by some reaction.

  The electrolyte 50 may be an ionic liquid instead of the organic solvent. As the ionic liquid, for example, a known iodine salt such as a pyridinium salt, an imidazolium salt, or a triazolium salt, and a room temperature molten salt that is in a molten state near room temperature is used. Examples of such room temperature molten salts include 1-hexyl-3-methylimidazolium iodide, 1-ethyl-3-propylimidazolium iodide, dimethylimidazolium iodide, ethylmethylimidazolium iodide, and dimethylpropyl. Imidazolium iodide, butylmethylimidazolium iodide, or methylpropyl imidazolium iodide is preferably used.

  The electrolyte 50 may be a mixture of the ionic liquid and the organic solvent instead of the organic solvent.

An additive can be added to the electrolyte 50. As the _{additive, LiI, I 2, 4-} t- butylpyridine, guanidinium thiocyanate, 1-methylbenzimidazole, 1-butyl-benzimidazole and the like.

Furthermore, as the electrolyte 50, a nanocomposite gel electrolyte which is a pseudo-solid electrolyte obtained by kneading nanoparticles such as SiO ₂ , TiO ₂ , and carbon nanotubes with the above electrolyte may be used, and polyvinylidene fluoride may be used. Alternatively, an electrolyte gelled with an organic gelling agent such as a polyethylene oxide derivative or an amino acid derivative may be used.

  Next, the manufacturing method of the dye-sensitized solar cell 100 described above will be described with reference to FIGS. 2A and 2B are cross-sectional views showing a series of steps for forming a plurality of porous oxide semiconductor portions on the transparent conductive substrate of FIG. 1, and FIGS. 3A to 3D. FIG. 4 is a cross-sectional view showing a series of steps for supporting a photosensitizing dye on a plurality of porous oxide semiconductor portions in FIG. 2, and FIG. 4 (a) is sealed on the transparent conductive substrate in FIG. 3 (d). FIG. 4B is a cross-sectional view showing a sealing portion forming material pressure bonding step for pressure bonding a stopper portion forming material. FIG. 4B is an electrolyte arrangement in which an electrolyte is arranged on a plurality of porous oxide semiconductor portions in FIG. It is sectional drawing which shows a process.

  First, the transparent conductive substrate 10 is prepared. The transparent conductive substrate 10 can be obtained by forming a transparent conductive film 12 on a transparent substrate 11 as shown in FIG. As a method for forming the transparent conductive film 12, a sputtering method, a vapor deposition method, a spray pyrolysis method, a CVD method, or the like is used.

[Porous oxide semiconductor part forming step]
Next, a paste for forming a porous oxide semiconductor layer is printed in two regions on the transparent conductive film 12 of the transparent conductive substrate 10 that are separated from each other. The paste for forming a porous oxide semiconductor layer contains a resin such as polyethylene glycol and a solvent such as terpineol in addition to the oxide semiconductor particles. As a printing method of the paste for forming the porous oxide semiconductor layer, for example, a screen printing method, a doctor blade method, a bar coating method, or the like can be used.

  Next, the porous oxide semiconductor layer forming paste is fired to form the porous oxide semiconductor portions 20a and 20b on the transparent conductive film 12 (see FIG. 2B). The firing temperature varies depending on the oxide semiconductor particles, but is usually 140 to 600 ° C., and the firing time also varies depending on the oxide semiconductor particles, but is usually 1 to 5 hours.

[Photosensitizing dye supporting step]
Next, as shown in FIG. 3A, the porous oxide semiconductor portion 20 b is covered with a mask member 80. The mask member 80 can be formed, for example, by adhering an annular adhesive 60 on the transparent conductive substrate 10 and then covering the opening of the adhesive 60 with the cover member 70. Thus, the first structure 90 is obtained.

  Here, as the adhesive 60, for example, it is preferable to use the same material as that constituting the sealing portion 40. Since these have high sealing ability with respect to the organic solvent, the organic solvent contained in the dye solution can be sufficiently suppressed from entering the mask member 80.

  As a material constituting the cover member 70, a material having a high sealing ability with respect to an organic solvent is preferable. As such a material, for example, a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, or a metal such as titanium can be used.

  Next, as shown in FIG. 3B, the porous oxide semiconductor portion 20a of the first structure 90 is loaded with a photosensitizing dye of a type different from the common photosensitizing dye. For this purpose, the first structure 90 is immersed in a first dye solution containing a photosensitizing dye, and the photosensitizing dye is adsorbed on the porous oxide semiconductor portion 20a (first immersion step). .

  Next, as shown in FIG. 3C, the cover member 70, which is a part of the mask member 80, is peeled from the adhesive 60, and the porous oxide semiconductor portion 20b on which no photosensitizing dye is supported. To expose. In this way, the second structure 110 is obtained.

  Subsequently, as shown in FIG. 3D, the common photosensitizing dye is supported on the porous oxide semiconductor portions 20a and 20b of the second structure 110 (second immersion step). For this purpose, the second structure 110 is immersed in a second dye solution containing a photosensitizing dye, and the photosensitizing dye is adsorbed on the porous oxide semiconductor portions 20a and 20b.

  Thus, two types of photosensitizing dyes are supported on the porous oxide semiconductor portion 20a, and only one type of photosensitizing dye is supported on the porous oxide semiconductor portion 20b. That is, in the porous oxide semiconductor parts 20a and 20b, the number of types of photosensitizing dyes is different from each other, and a common photosensitizing dye is supported on the porous oxide semiconductor parts 20a and 20b.

[Sealing part forming material crimping process]
4A, for example, an annular sealing portion forming material 40A is disposed on the transparent conductive substrate 10, for example. At this time, the porous oxide semiconductor portions 20a and 20b are arranged inside the sealing portion forming material 40A. Thereafter, the sealing portion forming material 40 </ b> A is melt bonded to the transparent conductive substrate 10.

[Electrolyte placement process]
Next, as shown in FIG. 4B, for example, the electrolyte 50 is disposed on the transparent conductive substrate 10 and inside the sealing portion forming material 40A. The electrolyte 50 can be disposed on the transparent conductive substrate 10 by being injected or printed inside the annular sealing portion forming material 40A.

[Lamination process]
Next, the counter electrode 30 is opposed to and superimposed on the porous oxide semiconductor portions 20a and 20b. Then, the sealing portion forming material 40A is pressurized while being heated and melted. Thus, the production of the dye-sensitized solar cell 100 is completed by bonding the transparent conductive substrate 10 and the counter electrode 30 so that the electrolyte 50 is disposed between the transparent conductive substrate 10 and the counter electrode 30 (see FIG. 1). ). At this time, the sealing portion forming material 40 </ b> A becomes the sealing portion 40.

  When the dye-sensitized solar cell 100 is manufactured as described above, in the obtained dye-sensitized solar cell 100, a common photosensitizing dye is supported on the porous oxide semiconductor portions 20a and 20b. If what can give the outstanding photoelectric conversion characteristic to the dye-sensitized solar cell 100 is used as a dye-sensitized dye, the fall of the photoelectric conversion characteristic as the dye-sensitized solar cell 100 whole can fully be suppressed. Moreover, since the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor portions 20a and 20b is different from each other, it is possible to impart excellent design to the dye-sensitized solar cell 100. That is, according to the manufacturing method of the dye-sensitized solar cell 100 described above, the dye-sensitized solar cell 100 that can sufficiently suppress the decrease in photoelectric conversion characteristics is manufactured even when excellent designability is imparted. It becomes possible. In addition, the appropriate immersion time of the photosensitizing dye usually varies depending on the type of the photosensitizing dye, but according to the above production method, the immersion time of each photosensitizing dye can be freely controlled. It is also possible to ensure an appropriate immersion time for each photosensitizing dye. Moreover, according to the said manufacturing method, the mask member 80 is comprised so that it may have the cyclic | annular adhesive 60 and the cover member 70 which covers the porous oxide semiconductor part 20b with the adhesive 60, A cover member Since the adhesion between the adhesive 70 and the adhesive 60 can be increased, the first dye solution and the second dye solution are sufficiently prevented from entering the inside of the mask member 80. On the other hand, when removing the mask member 80, the porous oxide semiconductor portion 20b can be easily exposed by simply removing the cover member 70.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the sealing portion 40 is directly bonded to the transparent conductive substrate 10. However, as in the dye-sensitized solar cell 200 illustrated in FIG. 5, the sealing portion 40 is a colored inorganic sealing portion. It may be bonded to the transparent conductive substrate 10 via 290. In this case, since the color can be visually recognized not only at the porous oxide semiconductor portions 20a and 20b but also at the position of the inorganic sealing portion 290, more excellent design can be imparted to the dye-sensitized solar cell 200. .

  Moreover, in the said embodiment, although only one dye-sensitized solar cell is formed on the transparent conductive substrate 10, like the dye-sensitized solar cell 300 shown in FIG. In addition, a plurality of dye-sensitized solar cells 25a and 25b may be provided. In this case, the dye-sensitized solar cell 25a includes a transparent conductive film 12a, a porous oxide semiconductor part 20a provided on the transparent conductive film 12a, and a counter electrode 30a provided to face the porous oxide semiconductor part 20a. And the annular sealing part 40 which connects the transparent conductive substrate 10 and the counter electrode 30a, and the electrolyte 50 provided between the transparent conductive film 12a and the counter electrode 30a. Similarly, the dye-sensitized solar cell 25b includes a transparent conductive film 12b, a porous oxide semiconductor part 20b provided on the transparent conductive film 12b, and a counter electrode 30b provided to face the porous oxide semiconductor part 20b. And the annular sealing part 40 which connects the transparent conductive substrate 10 and the counter electrode 30b, and the electrolyte 50 provided between the transparent conductive film 12b and the counter electrode 30b. Here, the thicknesses of the porous oxide semiconductor portions 20a and 20b of the dye-sensitized solar cells 25a and 25b may be the same or different, but are preferably the same. In this case, the voltage in the dye-sensitized solar cells 25a and 25b can be made close, and the power generation amount of each of the dye-sensitized solar cells 25a and 25b is also close, so the dye-sensitized solar cells 25a and 25b are close. Even when connected in series or in parallel, the overall power characteristics are not disturbed, and when supplying power from the dye-sensitized solar cell 300 to an external device, desired power can be supplied accurately.

  The thicknesses of the porous oxide semiconductor portions 20a and 20b are the same as the thickness of the porous oxide semiconductor portion 20a in which two types of dyes are supported, but the porous oxide in which only one type of dye is supported. You may make it lower than the thickness of the semiconductor part 20b.

  Moreover, although the said embodiment demonstrated as an example the case where the two porous oxide semiconductor parts 20a and 20b were provided on the transparent conductive substrate 10, a porous oxide semiconductor part is a transparent conductive substrate. Three or more may be provided on 10.

  In this case, in order to manufacture a dye-sensitized solar cell, the transparent conductive substrate 10 and the counter electrode 30 are disposed so that the electrolyte 50 is disposed between the second immersion step and the transparent conductive substrate 10 and the counter electrode 30. Further repeating the second dipping step between the bonding steps to be bonded so that the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor parts is different from each other. Just do it.

  Further, in the above embodiment, the co-adsorbent is not adsorbed on any of the porous oxide semiconductor portions 20a and 20b, but even if the co-adsorbent is adsorbed on at least one of the porous oxide semiconductor portions 20a and 20b. Good.

  In this case, since the co-adsorbent does not develop color, if the co-adsorbent is adsorbed to at least one porous oxide semiconductor portion of the porous oxide semiconductor portions 20a and 20b, the porous adsorbed by the co-adsorbent The color in the oxide semiconductor portion can be reduced. As a result, it is possible to realize color shading as the entire dye-sensitized solar cell.

  The coadsorbent is not particularly limited as long as it can suppress the association between the photosensitizing dyes. For example, as a coadsorbent, deoxycholic acid, chenodeoxycholic acid, cholic acid, hyodeoxycholic acid, salts thereof, and the like can be used.

  Furthermore, in the above-described embodiment, the photosensitizing dye is supported on the porous oxide semiconductor portions 20a and 20b, and then the annular sealing portion forming material 40A is melt-pressed on the transparent conductive substrate 10. Before the photosensitizing dye is carried on the oxide semiconductor portions 20a and 20b, the annular sealing portion forming material 40A may be melt-bonded to the transparent conductive substrate 10.

  Hereinafter, the content of the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
First, TEC15 glass (trade name, manufactured by Pilkington), which is a tin oxide-coated glass sheet, was prepared as a transparent conductive substrate. The dimensions of the TEC glass were 100 mm × 100 mm × 2.2 mm. Then, 21NR (trade name, manufactured by JGC Catalysts & Chemicals Co., Ltd.) as a titanium oxide paste was applied to each of two regions of the surface of the transparent conductive substrate separated from each other by a screen printing method. Then, the transparent conductive substrate coated with the titanium oxide paste is put in a hot air circulation type oven and baked at 500 ° C. for 1 hour, and one porous oxide semiconductor layer having a thickness of 12 μm is formed on the transparent conductive substrate. The 1st porous oxide semiconductor part which consists of 1 and the 2nd porous oxide semiconductor layer which consists of one porous oxide semiconductor layer whose thickness is 12 micrometers were obtained.

  Next, on the transparent conductive substrate, Binnel 4164 (trade name, manufactured by DuPont) as an annular adhesive was melt-pressed so as to surround the second porous oxide semiconductor portion. The adhesive had a thickness of 40 μm and a width of 500 μm. Then, the opening of the annular adhesive was covered with a cover member made of polyethylene terephthalate having a thickness of 75 μm. Thus, a mask member was formed.

  Next, 18.5 cm × 16.5 cm in the center of a sheet of 19.5 cm × 17.5 cm × 100 μm made of Nucrel (Mitsui DuPont Polychemical Co., Ltd., melting point: 98 ° C.) which is an ethylene-methacrylic acid copolymer. A square annular resin sheet having an opening of × 100 μm was prepared. And this resin sheet was arrange | positioned on the transparent conductive substrate. At this time, the first porous oxide semiconductor portion and the second porous oxide semiconductor portion were arranged inside the resin sheet. Subsequently, the resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the transparent conductive substrate and fix the sealing portion forming material. Thus, the first structure was obtained.

  Next, the first structure is dissolved in a first dye solution in which D131 dye (absorption peak wavelength: 420 nm) as a photosensitizing dye is dissolved in 1-propanol to a concentration of 0.05 mM. The D131 dye was supported on the first porous oxide semiconductor portion that was immersed for a period of time and not covered with the mask member.

  Subsequently, the cover member which is a part of the mask member was peeled off from the adhesive to obtain a second structure.

  Then, the second structure is made to have a concentration of 0.2 mM in a mixed solvent of 1: 1 volume ratio of acetonitrile and t-butanol with N719 dye (absorption peak wavelength: 550 nm) which is a common photosensitizing dye. The N719 dye was supported on the first and second porous oxide semiconductor parts by immersing in a second dye solution dissolved in 24 hours.

Next, inside the sealing portion forming material, a volatile solvent composed of methoxypropionitrile is used as a main solvent, hexylmethylimidazolium iodide (HMImI) is 0.6 mM, and N-methylbenzimidazole (NMBI) is 0. An electrolyte containing 0.2 mM 0.2 mM 3-methoxypropionitrile (MPN) was injected. At this time, the concentration of I ₃ ⁻ in the electrolyte was 6 × 10 ⁻⁸ M.

  On the other hand, a counter electrode substrate made of titanium of 9 cm × 9 cm × 0.04 mm was prepared. Then, a platinum catalyst layer having a thickness of 10 nm was formed on the counter electrode substrate by sputtering. In this way, two counter electrodes were obtained.

  Next, the two counter electrodes were respectively opposed to the first and second porous oxide semiconductor portions, and the sealing portion forming material on the transparent conductive substrate and the counter electrode were superposed under atmospheric pressure. . Then, under a reduced pressure of 800 Pa, using a press machine, the sealing portion forming material was heated and melted at 148 ° C. while being pressurized at 5 MPa through the counter electrode to obtain a sealing portion. Thus, a dye-sensitized solar cell was obtained.

(Example 2)
As the first dye solution, a D149 dye (absorption peak wavelength: 530 nm) dissolved in a 1: 1 mixed solvent of acetonitrile and t-butanol so as to be 0.05 mM is used as the second dye solution. The dye was the same as in Example 1 except that a Z907 dye (absorption peak wavelength: 530 nm) was dissolved in a 1: 1 mixed solvent of acetonitrile and t-butanol to a concentration of 0.2 mM. A sensitized solar cell was produced.

(Example 3)
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the concentration of I ₃ ⁻ in the electrolyte was changed from 6 × 10 ⁻⁸ M to 0.002 M.

Example 4
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the thickness of the porous oxide semiconductor layer constituting the second porous oxide semiconductor portion was changed from 12 μm to 9 μm.

(Example 5)
Substances to be dissolved in the mixed solvent in the second dye solution are changed from only N719 dye, which is a common photosensitizing dye, to N719 dye, which is a common photosensitizing dye, and 2-hexadecylmalonic acid, which is a coadsorbent ( The dye-sensitized solar cell was produced in the same manner as in Example 1 except that the concentration of HDMA in the second dye solution was changed to 3 mM.

(Example 6)
Black containing Cu-Cr-Mn-based black pigment in the region where the adhesive is to be melt-pressed when the titanium oxide paste is applied to two regions of the surface on the transparent conductive substrate that are spaced apart from each other A glass paste containing a low melting point glass frit was applied, and the transparent conductive substrate coated with the titanium oxide paste and the glass paste was placed in a hot air circulation type oven and baked at 500 ° C. for 1 hour to obtain a black film having a thickness of 15 μm. A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the inorganic sealing portion was formed and the adhesive was melt-pressed thereon.

(Comparative Example 1)
After the first and second porous oxide semiconductor portions are formed, the first and second porous oxide semiconductor portions are loaded with the photosensitizing dye as follows, whereby the first porous oxide semiconductor is formed. A dye-sensitized solar cell was produced in the same manner as in Example 1, except that one part of D131 dye was supported on the part and N719 dye was supported on the second porous oxide semiconductor part.
That is, first, a container having first and second accommodation spaces, in which the first and second accommodation spaces are partitioned by a partition wall, was prepared. Next, a first dye solution containing D131 dye and a second dye solution containing N719 dye were injected into each of the first and second accommodation spaces of the container. Subsequently, the container was brought into close contact with the transparent conductive substrate. At this time, the first porous oxide semiconductor portion was accommodated in the first accommodating space, and the second porous oxide semiconductor portion was accommodated in the second accommodating space. Then, the first porous oxide semiconductor part is immersed in the first dye solution, the D131 dye is supported on the first porous oxide semiconductor part, and the second porous oxide semiconductor part is immersed in the second dye solution, N719 dye was supported on the two porous oxide semiconductor part.

(Evaluation of photoelectric conversion characteristics)
About the dye-sensitized solar cell of Examples 1-6 and the comparative example 1, the output was measured under the illumination intensity of 200 lux using the white LED light source. The results are shown in Table 1.

  From the results shown in Table 1, it was found that the outputs of Examples 1 to 6 were sufficiently higher than those of Comparative Example 1. Moreover, all of Examples 1-6 and Comparative Example 1 had excellent design properties.

  From this, according to the dye-sensitized solar cell of this invention, even if it was a case where the outstanding designability was provided, it was confirmed that the fall of a photoelectric conversion characteristic can fully be suppressed.

DESCRIPTION OF SYMBOLS 10 ... Transparent conductive board | substrate 20a, 20b ... Porous oxide semiconductor part 30, 30a, 30b ... Counter electrode (electrode)
31 ... Transparent conductive film 40 ... Sealing portion 50 ... Electrolyte 60 ... Adhesive 70 ... Cover member 80 ... Mask member 90 ... First structure 100, 200, 300 ... Dye-sensitized solar cell 110 ... Second structure 290 ... Inorganic sealing part

Claims (8)

A transparent conductive substrate;
A plurality of porous oxide semiconductor portions that carry a photosensitizing dye and are provided on the transparent conductive substrate so as to be separated from each other ;
A counter electrode provided opposite to the porous oxide semiconductor portion;
An electrolyte disposed between the transparent conductive substrate and the counter electrode ;
An annular adhesive provided on the transparent conductive substrate and individually surrounding the remaining porous oxide semiconductor portions excluding one porous oxide semiconductor portion among the plurality of porous oxide semiconductor portions ; Prepared,
The number of types of the photosensitizing dyes carried on the plurality of porous oxide semiconductor parts is different from each other,
The photosensitizing dye includes a common photosensitizing dye common to the plurality of porous oxide semiconductor portions, and the porous oxide semiconductor portion is composed of at least one porous oxide semiconductor layer. , Dye-sensitized solar cells.   Among the plurality of porous oxide semiconductor portions, in the porous oxide semiconductor portion on which a plurality of types of photosensitizing dyes are supported, the plurality of types of photosensitizing dyes have different absorption peak wavelengths. Item 2. The dye-sensitized solar cell according to Item 1. The electrolyte is, I ^- and I ₃ ^- comprises a redox couple consisting of the I ₃ in the electrolyte ^- the concentration of at most 0.006M, dye-sensitized solar cell according to claim 1 or 2.   The dye-sensitized sun according to any one of claims 1 to 3, wherein the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate have the same thickness from the transparent conductive substrate. battery.   5. The coadsorbent is adsorbed on at least one porous oxide semiconductor portion of the plurality of porous oxide semiconductor portions provided on the transparent conductive substrate. The dye-sensitized solar cell according to Item.   A sealing part that connects the transparent conductive substrate and the counter electrode is further provided, and a colored inorganic sealing part is provided between the sealing part and the transparent conductive substrate. The dye-sensitized solar cell according to any one of 5. A porous oxide semiconductor part forming step of forming a plurality of porous oxide semiconductor parts on a transparent conductive substrate so as to be separated from each other ;
A first structure is obtained by covering a remaining porous oxide semiconductor portion excluding one porous oxide semiconductor portion among the plurality of porous oxide semiconductor portions with a mask member, and then obtaining the first structure. A first immersing step of immersing the body in a first dye solution containing a photosensitizing dye;
After removing at least a part of the mask member from one porous oxide semiconductor portion of the remaining porous oxide semiconductor portions covered with the mask member, the second structure is obtained. The structure is immersed in a second dye solution containing a photosensitizing dye of a different type from the photosensitizing dye, and the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor parts is A second dipping step to make them different from each other;
A bonding step of bonding the transparent conductive substrate and the counter electrode so that an electrolyte is disposed between the transparent conductive substrate and the counter electrode,
The porous oxide semiconductor portion is composed of at least one porous oxide semiconductor layer ;
The mask member is
On the transparent conductive substrate, an annular adhesive attached so as to individually surround the porous oxide semiconductor part, and
The manufacturing method of a dye-sensitized solar cell which has a cover member which covers the said porous oxide semiconductor part with the said adhesive agent . A porous oxide semiconductor part forming step of forming a plurality of porous oxide semiconductor parts on a transparent conductive substrate so as to be separated from each other ;
A first structure is obtained by covering a remaining porous oxide semiconductor portion excluding one porous oxide semiconductor portion among the plurality of porous oxide semiconductor portions with a mask member, and then obtaining the first structure. A first immersing step of immersing the body in a first dye solution containing a photosensitizing dye;
After removing at least a part of the mask member from one porous oxide semiconductor portion of the remaining porous oxide semiconductor portions covered with the mask member, the second structure is obtained. A second immersing step of immersing the structure in a second dye solution containing a photosensitizing dye of a type different from the photosensitizing dye;
Repeating the second immersion step so that the number of types of photosensitizing dyes carried on the plurality of porous oxide semiconductor parts is different from each other;
A bonding step of bonding the transparent conductive substrate and the counter electrode so that an electrolyte is disposed between the transparent conductive substrate and the counter electrode,
The porous oxide semiconductor portion is composed of at least one porous oxide semiconductor layer ;
The mask member is
On the transparent conductive substrate, an annular adhesive attached so as to individually surround the porous oxide semiconductor part, and
The manufacturing method of a dye-sensitized solar cell which has a cover member which covers the said porous oxide semiconductor part with the said adhesive agent .

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