JP2019169658A - Photoelectrode, dye-sensitized solar cell, production method of the same, and dye solution for producing photoelectrode of dye-sensitized solar cell - Google Patents

Abstract

To further increase photoelectric conversion efficiency of a DSC.SOLUTION: A photoelectrode 10 including: a photoelectrode conductive layer 14; and an inorganic semiconductor layer 16 located on the photoelectrode conductive layer 14 is used. A sensitizing dye supported on the inorganic semiconductor layer 16 and an amine compound are contained. The amine compound is at least one selected from aliphatic amines and alicyclic amines. An amount of amine compound supported on the inorganic semiconductor layer 16 is 0.2 to 5.0 mg/cm. A sensitizing dye and an amine compound are supported on the inorganic semiconductor layer 16 on the photoelectrode conductive layer 14. In the photoelectrode 10, an amount of amine compound supported on the inorganic semiconductor layer 16 is 0.2 to 5.0 mmol/cm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photoelectrode, a dye-sensitized solar cell, a manufacturing method thereof, and a dye solution for manufacturing a photoelectrode of a dye-sensitized solar cell.

Photovoltaic power generation has achieved certain results as a new energy source. As solar cells, mainly silicon-based solar cells are most popular. Silicon-based solar cells have problems such as stable supply of high-purity silicon as a raw material and high cost.
As another solar cell, there is a dye-sensitized solar cell (DSC). DSC can be easily manufactured and its raw materials are inexpensive. For this reason, DSC has expectations as a next-generation solar cell.
As the DSC, there is a so-called Gretzel type solar cell.
A Gretzel-type DSC includes a photoelectrode, a counter electrode facing the photoelectrode, and an electrolytic solution positioned between the two electrodes. The photoelectrode has, for example, a conductive layer and a semiconductor layer located on the conductive layer. A sensitizing dye is adsorbed on the surface of the semiconductor layer.
In general, the photoelectric conversion efficiency of DSC is lower than the photoelectric conversion efficiency of silicon-based solar cells.

  For example, Patent Document 1 discloses a DSC having a porous titanium oxide layer that exhibits a predetermined color depending on the combination of the type of sensitizing dye and the particle size of titanium oxide fine particles. According to the invention of Patent Document 1, the photoelectric conversion efficiency and the design are improved.

JP 2010-113905 A

However, the power generation efficiency of the conventional DSC is not yet satisfactory.
Accordingly, an object of the present invention is to provide a DSC that can further increase the photoelectric conversion efficiency.

The present invention has the following aspects.
[1] containing a conductive layer, an inorganic semiconductor layer located on the conductive layer, and a sensitizing dye and an amine compound carried on the inorganic semiconductor layer,
The amine compound is at least one selected from aliphatic amines and alicyclic amines,
The supported amount of the amine compound to the inorganic semiconductor layer is 0.2~5.0mg / cm ^3, the photoelectrode.
[2] The photoelectrode according to [1], wherein the amount of the amine compound supported on the inorganic semiconductor layer is 70 to 3700 mmol with respect to 1 mmol of the sensitizing dye.

[3] Dye sensitization comprising the photoelectrode according to [1] or [2], a counter electrode facing the photoelectrode, and a charge transfer body positioned between the photoelectrode and the counter electrode Type solar cell.

[4] containing a sensitizing dye and at least one amine compound selected from aliphatic amines and alicyclic amines,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume,
Content of the said amine compound is 1.0-1000 mg / L with respect to a total volume, The dye solution for photoelectrode manufacture of a dye-sensitized solar cell.
[5] containing a sensitizing dye and at least one amine compound selected from aliphatic amines and alicyclic amines;
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume,
Content of the said amine compound is 10-5200 mmol / L with respect to a total volume, The dye solution for photoelectrode manufacture of a dye-sensitized solar cell.
[6] The dye solution for producing a photoelectrode of a dye-sensitized solar cell according to [4] or [5], wherein the content of the amine compound is 70 to 3700 mmol with respect to 1 mmol of the sensitizing dye.

[7] The inorganic semiconductor layer located on the conductive layer carries a sensitizing dye and at least one amine compound selected from aliphatic amines and alicyclic amines, and the amine compound is carried on the inorganic semiconductor layer. A method for producing a photoelectrode, wherein a photoelectrode having an amount of 0.2 to 5.0 mg / cm ³ is obtained.
[8] The method for producing a photoelectrode according to [7], wherein the dye solution containing the amine compound is brought into contact with the inorganic semiconductor layer, and the amine compound is supported on the inorganic semiconductor layer.
[9] The dye solution contains the sensitizing dye and the amine compound,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L in the total volume of the dye solution,
Content of the said amine compound is a manufacturing method of the photoelectrode as described in [8] which is 1.0-1000 mg / L in the total volume of the said pigment | dye solution.
[10] The dye solution contains the sensitizing dye and the amine compound,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume of the dye solution,
Content of the said amine compound is a manufacturing method of the photoelectrode as described in [8] which is 10-5200 mmol / L with respect to the total volume of the said pigment | dye solution.
[11] The dye solution contains the sensitizing dye and the amine compound,
Content of the said amine compound in the said dye solution is a manufacturing method of the photoelectrode in any one of [8]-[10] which is 70-3700 mmol with respect to 1 mmol of the said sensitizing dye.

[12] A photoelectrode is obtained by the photoelectrode manufacturing method according to any one of [7] to [11], and a counter electrode facing the inorganic semiconductor layer of the obtained photoelectrode is provided, and the photoelectrode A method for producing a dye-sensitized solar cell, wherein a charge transfer body is provided between the counter electrode and the counter electrode.

  According to the DSC of the present invention, the photoelectric conversion efficiency can be further increased.

It is sectional drawing of the dye-sensitized solar cell which concerns on one Embodiment of this invention.

(Dye-sensitized solar cell)
The dye-sensitized solar cell (DSC) of the present invention has a photoelectrode, a counter electrode, and a charge transfer body.
Hereinafter, the photoelectrode of the present invention and the dye-sensitized solar cell (DSC) using the photoelectrode will be described with an example.

  The DSC 1 in FIG. 1 includes a photoelectrode 10, a counter electrode 20, a charge transfer body 30, and a sealing material 40. The photoelectrode 10 and the counter electrode 20 are opposed to each other. The charge transfer body 30 is located between the photoelectrode 10 and the counter electrode 20. The sealing material 40 seals the charge transfer body 30. The charge transfer body 30 is in contact with both the photoelectrode 10 and the counter electrode 20.

  At least one of the photoelectrode 10 and the counter electrode 20 has optical transparency. The light-transmitting photoelectrode 10 or counter electrode 20 forms a light incident surface. In this paper, the light transmittance in the photoelectrode 10 or the counter electrode 20 is to transmit light to such an extent that the DSC 1 can generate power.

The photoelectrode 10 has a photoelectrode support 12, a photoelectrode conductive layer 14, and an inorganic semiconductor layer 16. The photoelectrode conductive layer 14 is located on the photoelectrode support 12. The inorganic semiconductor layer 16 is located on the photoelectrode conductive layer 14. That is, the photoelectrode support 12, the photoelectrode conductive layer 14, and the inorganic semiconductor layer 16 are positioned in this order.
The inorganic semiconductor layer 16 is in contact with the charge transfer body 30. The inorganic semiconductor layer 16 covers a part of the photoelectrode conductive layer 14. A part of the photoelectrode conductive layer 14 is in contact with the charge transfer body 30 outside the inorganic semiconductor layer 16.
The photoelectrode conductive layer 14 has an exposed portion 18 outside the sealing material 40. The exposed portion 18 is exposed to the outside of the DSC 1.

  The photoelectrode support 12 is a glass plate, a resin plate, a film or a sheet (the resin plate, film, or sheet may be collectively referred to as a resin plate), a metal foil, or the like. When the photoelectrode 10 forms a light incident surface, the photoelectrode support 12 is light transmissive. In this case, the photoelectrode support 12 is preferably a so-called transparent substrate.

  When the photoelectrode support 12 is a glass plate, the material is soda lime glass, quartz glass, borosilicate glass, Vycor glass, alkali-free glass, blue plate glass, white plate glass, or the like.

When the photoelectrode support 12 is a resin plate or the like, the material is polyacryl, polycarbonate, polyester, polyimide, polystyrene, polyvinyl chloride, polyamide or the like.
The material of the photoelectrode support 12 is preferably a resin, and more preferably polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). If the photoelectrode support 12 is made of resin, the DSC 1 can be made thinner and lighter. In addition, if the photoelectrode support 12 is made of resin, it is easy to impart flexibility to the DSC 1.

The photoelectrode support 12 may be a rigid support or a flexible support having flexibility.
The thickness of the photoelectrode support 12 is not particularly limited, and is preferably 10 μm to 5 mm, for example. The thickness of the photoelectrode support 12 is an average value of 10 arbitrary points measured with a contact-type micrometer.

The photoelectrode conductive layer 14 is not particularly limited as long as it has conductivity. The photoelectrode conductive layer 14 is a conventionally known DSC conductive layer.
When the photoelectrode 10 forms a light incident surface, the photoelectrode conductive layer 14 is light transmissive. That is, the photoelectrode conductive layer 14 is preferably a so-called transparent conductive layer.

The material of the photoelectrode conductive layer 14 is a metal such as gold, platinum, silver, copper, chromium, tungsten, aluminum, magnesium, titanium, nickel, manganese, zinc, iron, and alloys thereof; fluorine-doped tin oxide (FTO), sodium, sodium - potassium alloy, lithium, magnesium, aluminum, magnesium - silver mixture, a magnesium - indium mixture, an aluminum - lithium alloy, Al / _Al 2 _{O 3} mixture, Al / LiF mixture, CuI, indium tin oxide (ITO) , SnO _2, aluminum zinc oxide (AZO), indium zinc oxide (IZO), gallium zinc oxide (GZO) conductive transparent inorganic material such as a conductive transparent polymer. These materials may be used alone or in combination of two or more.

The thickness of the photoelectrode conductive layer 14 is appropriately determined according to the material constituting the photoelectrode conductive layer 14.
When the photoelectrode conductive layer 14 is a metal, the thickness of the photoelectrode conductive layer 14 is preferably 10 to 50 nm. If the thickness of the photoelectrode conductive layer 14 is equal to or greater than the above lower limit value, it is easy to prevent defects. If the thickness of the photoelectrode conductive layer 14 is less than or equal to the above upper limit value, the light transmittance can be easily improved.
When the photoelectrode conductive layer 14 is a conductive transparent inorganic material or a conductive transparent polymer, the thickness of the photoelectrode conductive layer 14 is preferably 100 to 500 μm. If the thickness of the photoelectrode conductive layer 14 is equal to or greater than the lower limit, it is easy to prevent defects. If the thickness of the photoelectrode conductive layer 14 is not more than the above upper limit value, the light transmittance can be further improved.
The method for measuring the thickness of the photoelectrode conductive layer 14 is, for example, the following method. The total thickness T1 of the photoelectrode conductive layer 14 and the photoelectrode support 12 is measured with a micrometer. Arbitrary 10 points of thickness T1 are measured, and the average value is ave (T1). The thickness T2 of the photoelectrode support 12 is measured with a micrometer. Arbitrary 10 points of thickness T2 are measured, and the average value is ave (T2). Let ave (T1) −ave (T2) be the thickness of the photoelectrode conductive layer 14.

  The inorganic semiconductor layer 16 may be any semiconductor material that can adsorb a sensitizing dye. Examples of the semiconductor material include oxides such as titanium oxide, zinc oxide, indium oxide, tin oxide, and gallium oxide, tin sulfide, indium sulfide, zinc sulfide, cuprous oxide, molybdenum trioxide, vanadium pentoxide, and tungsten oxide. Oxides such as copper (I) thiocyanate, copper iodide, molybdenum disulfide, molybdenum diselenide, copper (I) sulfide, and the like.

  The inorganic semiconductor layer 16 may be a dense layer or a porous layer. In view of further improving the photoelectric conversion efficiency of the DSC 1, the inorganic semiconductor layer 16 is preferably a porous layer. Further, the inorganic semiconductor layer 16 is more preferably a porous layer in which fine particles are joined by physical collision by sintering or powder spraying.

The average particle diameter of the fine particles forming the inorganic semiconductor layer 16 is not particularly limited, and is, for example, 10 to 500 nm. When the average particle diameter of the fine particles is within the above range, the specific surface area of the inorganic semiconductor layer 16 is increased and the utilization factor of incident light is easily increased.
The average particle diameter of the fine particles is, for example, a peak value of a volume average diameter distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus. Further, for example, the average particle diameter of the fine particles is an average value of the major diameters of arbitrary ten fine particles. The major axis of the fine particle is a value determined by SEM observation.

The specific surface area of the inorganic semiconductor layer 16 is preferably ^{10~200m 2 / g, 50~100m 2 /} g are preferred. When the specific surface area is not less than the above lower limit, the amount of the sensitizing dye supported can be further increased. If the specific surface area is not more than the above upper limit, the strength of the inorganic semiconductor layer 16 can be increased. The specific surface area of the inorganic semiconductor layer 16 is a value determined by a gas adsorption method.

For example, the thickness of the inorganic semiconductor layer 16 is preferably 1 to 40 μm, more preferably 3 to 30 μm, and still more preferably 5 to 25 μm. If the thickness of the inorganic semiconductor layer 16 is equal to or greater than the above lower limit value, the amount of light that can be captured increases and the amount of power generation can be increased. If the thickness of the inorganic semiconductor layer 16 is not more than the above upper limit value, it is easy to carry the sensitizing dye on the inorganic semiconductor layer 16. In addition, if the thickness of the inorganic semiconductor layer 16 is less than or equal to the above upper limit value, the flexibility of the inorganic semiconductor layer 16 is likely to increase. For this reason, when the DSC 1 has flexibility, the inorganic semiconductor layer 16 is hardly damaged when the DSC 1 is bent.
The method for measuring the thickness of the inorganic semiconductor layer 16 is, for example, the following method. The thickness T10 of the photoelectrode 10 is measured with a micrometer. The thickness T10 of arbitrary 10 points | pieces is measured, and the average value is set to ave (T10). The total thickness T1 of the photoelectrode support 12 and the photoelectrode conductive layer 14 is measured with a micrometer. Arbitrary 10 points of thickness T1 are measured, and the average value is ave (T1). Let ave (T10) −ave (T1) be the thickness of the inorganic semiconductor layer 16.

Sensitizing dyes are cis-di (thiocyanato) -bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) (hereinafter sometimes referred to as N3), cis-di (thiocyanato)- Bis (2,2′-bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) bis-TBA salt (hereinafter sometimes referred to as N719), cis-di (thiocyanato) -bis (2,2′- Bipyridyl-4,4′-dicarboxylic acid) ruthenium (II) tetra-TBA salt (hereinafter sometimes referred to as N712), tri (thiocyanato)-(4,4 ′, 4 ″ -tricarboxy-2,2 ': 6', 2 ″ -terpyridine) ruthenium tris-tetrabutylammonium salt (hereinafter sometimes referred to as N749), cis-di (thiocyanato)-(2,2′-bipyridyl-4,4′-dicarboxylic acid) ) (4,4′-bis (5′-hexylthio-5- (2,2′-bithienyl)) bipyridyl) ruthenium (II) mono-tetrabutylammonium salt (hereinafter sometimes referred to as black dye), etc. Ruthenium dyes: various organic dyes such as coumarin, polyene, cyanine, hemicyanine, thiophene, indoline, xanthene, carbazole, perylene, porphyrin, phthalocyanine, merocyanine, catechol and squarylium A donor-acceptor composite dye obtained by combining these dyes. Especially, it is preferable that a sensitizing dye contains at least 1 sort (s) of N3, N719, N712, and at least 1 sort (s) of N3, N719, and N712 is more preferable.
These sensitizing dyes may be used alone or in combination of two or more.

The amount of the sensitizing dye supported on the inorganic semiconductor layer 16 can be determined in consideration of the type of the sensitizing dye, the power generation capacity required for the DSC 1 and the like. The amount of the sensitizing dye supported on the inorganic semiconductor layer 16 is preferably 0.4 × 10 ^{−2 to} 2.0 × 10 ⁻² mmol / cm ³ , and 0.6 × 10 ^{−2 to} 1.2 × 10 ^−2. More preferred is mmol / cm ³ . If the amount of the sensitizing dye supported is not less than the above lower limit, the photoelectric conversion efficiency of DSC 1 can be further improved. When the amount of the sensitizing dye supported is within the above range, the inorganic semiconductor layer 16 supporting the dye transports an appropriate amount of carriers, and the photoelectric conversion efficiency can be further increased. If the carrying amount of the sensitizing dye is equal to or more than the lower limit value, the amount of carriers generated with respect to the amount of incident light increases, and the photoelectric conversion efficiency is further increased. When the amount of the sensitizing dye supported is not more than the above upper limit, the amount of the sensitizing dye adsorbed on the semiconductor surface becomes an appropriate amount, the carrier transport is improved, and the photoelectric conversion efficiency can be further increased.
The volume of the inorganic semiconductor layer 16 is a value obtained by multiplying the area calculated by measuring the length and width with a caliper or a ruler and the thickness measured by the above method.

  The amine compound may be an aliphatic amine, an alicyclic amine, or a combination of both.

Aliphatic amines are primary amines, secondary amines, tertiary amines, polyamines and the like. Among these, as the aliphatic amine, a tertiary amine is preferable. The hydrocarbon group of the aliphatic amine may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.
The primary amine is a primary amine having a hydrocarbon group having 1 to 12 carbon atoms such as methylamine, ethylamine, propylamine, isopropylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine and the like. Amines and the like.

  The secondary amine is a second amine having two hydrocarbon groups having 1 to 12 carbon atoms such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine and the like. Secondary amines, etc. The two hydrocarbon groups may be the same as or different from each other.

  Tertiary amines are trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, ethylenediamine, diethylenediamine, triethylenediamine, hexamethylenediamine, dodecamethylenediamine, diethylenetriamine. And tertiary amines having three hydrocarbon groups having 1 to 12 carbon atoms such as triethylenetetramine. The three hydrocarbon groups may be the same as or different from each other.

  A polyamine is an amine having two or more nitrogen atoms in the molecule. Examples of the polyamine include carbonization of 1 to 12 carbon atoms such as tetraethylenepentamine, N, N, N′N′-tetramethyl-1,4-butanediamine, and N, N, N′N′-tetramethylethylenediamine. And amines having a hydrogen group.

2-8 are respectively independently preferable, as for carbon number of the hydrocarbon group which an aliphatic amine has, 2-6 are more preferable, and 3-5 are more preferable. If the number of carbon atoms of the hydrocarbon group is within the above range, the photoelectric conversion efficiency of DSC 1 can be further improved.
These aliphatic amines may be used alone or in combination of two or more.

The alicyclic amine is an amine having an alicyclic hydrocarbon group having 3 to 10 carbon atoms, such as cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, cycloheptylamine, cyclooctylamine, 1,4-diaminocyclohexane, etc. Etc.
These alicyclic amines may be used alone or in combination of two or more.

  The amine compound is preferably an aliphatic amine, more preferably a tertiary amine, further preferably a tertiary amine having 3 to 5 carbon atoms in the hydrocarbon group, and particularly preferably tributylamine.

The amount of the amine compound supported on the inorganic semiconductor layer 16 is preferably 0.2 to 5.0 mmol / cm ³ , more preferably 0.5 to 2.5 mmol / cm ³ with respect to the total volume of the inorganic semiconductor layer 16. 1.0 to 2.0 mmol / cm ³ is more preferable. If the loading of the amine compound is equal to or greater than the above lower limit, the photoelectric conversion efficiency of DSC 1 can be further increased. If the amount of amine compound supported is too large, the amine compound may act as an impurity. For this reason, if the loading amount of the amine compound is not more than the above upper limit value, the amine compound is less likely to act as an impurity, and the photoelectric conversion efficiency of the DSC 1 can be further increased.

  The supported amount of the amine compound supported on the inorganic semiconductor layer is preferably 70 to 3700 mmol, more preferably 200 to 2200 mmol, more preferably 350 to 1700 mmol with respect to 1 mmol of the sensitizing dye supported on the inorganic semiconductor layer. Is more preferable. If the amount of amine compound supported is not less than the above lower limit, the amount of amine compound supported will be sufficient, and the photoelectric conversion efficiency of DSC 1 can be further improved. If the loading amount of the amine compound is not more than the above upper limit value, the amine compound is less likely to act as an impurity, and the photoelectric conversion efficiency of the DSC 1 can be further improved.

The counter electrode 20 includes a counter electrode support 22 and a counter electrode conductive layer 24. The counter electrode conductive layer 24 is located on the counter electrode support 22.
The photoelectrode 10 and the counter electrode 20 are opposed to each other with the inorganic semiconductor layer 16 and the counter electrode conductive layer 24 facing each other.
The counter electrode conductive layer 24 has an exposed portion 28 outside the sealing material 40. The exposed portion 28 is exposed to the outside of the DSC 1.

The material of the counter electrode support 22 is a glass plate, a resin plate, a film or sheet, a metal foil, or the like, like the material of the photoelectrode support 12. When the counter electrode 20 forms a light incident surface, the counter electrode support 22 has light transmittance. In this case, the counter electrode support 22 is preferably a so-called transparent support. The material of the counter electrode support 22 may be the same as or different from the material of the photoelectrode support 12.
The thickness of the counter electrode support 22 is preferably 10 μm to 5 mm, similarly to the thickness of the photoelectrode support 12. The thickness of the counter electrode support 22 may be the same as or different from the thickness of the photoelectrode support 12.

The material of the counter electrode conductive layer 24 is a metal, a conductive transparent inorganic material, a conductive transparent polymer, or the like, like the material of the photoelectrode conductive layer 14. The counter electrode conductive layer 24 and the photoelectrode conductive layer 14 may be the same or different. When the counter electrode 20 forms a light incident surface, the counter electrode conductive layer 24 is light transmissive. In this case, the counter electrode conductive layer 24 is preferably a so-called transparent conductive layer.
The thickness of the counter electrode conductive layer 24 is preferably 10 μm to 5 mm, similarly to the thickness of the photoelectrode conductive layer 14. The thickness of the counter electrode conductive layer 24 may be the same as or different from the thickness of the photoelectrode conductive layer 14.

  The charge transfer body 30 is an electrolytic solution, a gel electrolyte, or a solid electrolyte. The charge transfer body 30 of this embodiment is in contact with the inorganic semiconductor layer 16, the photoelectrode conductive layer 14, and the counter electrode conductive layer 24. The charge transfer body 30 has a redox pair capable of supplying electrons to the sensitizing dye.

  The electrolytic solution has a dispersion medium (in particular, sometimes referred to as “electrolytic solution dispersion medium”) and a redox pair dispersed in the electrolytic solution dispersion medium. The gel electrolyte and the solid electrolyte are gel electrolytes or solid electrolytes. In the method for producing the gel electrolyte and the solid electrolyte, for example, a gelling agent or a thickening agent is added to the electrolytic solution to form a gel or solid. If necessary, the solvent of the gel or solid charge transfer body is removed. The gel electrolyte and the solid electrolyte charge transfer body 30 can enhance the durability of the DSC 1.

  The electrolyte dispersion medium is a non-aqueous solvent, an ionic liquid, or the like. Non-aqueous solvents are acetonitrile, propionitrile, and the like. The ionic liquid is dimethylpropylimidazolium iodide, butylmethylimidazolium iodide, or the like.

The redox couple is a combination of a supporting electrolyte and a halogen molecule.
The supporting electrolyte includes metal iodides such as lithium iodide, sodium iodide and potassium iodide, iodides such as iodine salts such as tetraalkylammonium iodide, pyridinium iodide and imidazolium iodide; sodium bromide and bromide Bromine compounds such as metal bromides such as potassium, bromine salts such as tetraalkylammonium bromide, pyridinium bromide, imidazolium bromide.
The halogen molecule is an iodine molecule, a bromine molecule or the like.
As a combination of a supporting electrolyte and a halogen molecule, a combination of an iodide and an iodine molecule and a combination of a bromine compound and a bromine molecule are preferable.

The content of the supporting electrolyte relative to the total volume of the charge transfer body 30 can be determined in consideration of the type of the supporting electrolyte. For example, the content of the supporting electrolyte with respect to the total volume of the charge transfer body 30 is preferably 0.1 to 10 mmol / L, and more preferably 0.2 to 2 mmol / L.
The content of halogen molecules with respect to the total volume of the charge transfer body 30 can be determined in consideration of the content of the supporting electrolyte and the like. The content of halogen molecules with respect to the total volume of the charge transfer body 30 is preferably 0.001 to 1 mmol / L.

  The charge transfer body 30 may include t-butylpyridine. Since the charge transfer body 30 contains t-butylpyridine, it is easy to prevent a reverse electron transfer reaction.

  When the charge transfer body 30 is a gel electrolyte or a solid electrolyte, the charge transfer body 30 may include a conductive polymer.

The sealing material 40 is located between the photoelectrode 10 and the counter electrode 20. The sealing material 40 surrounds an arbitrary region in a plan view and seals the charge transfer body 30.
The sealing material 40 only needs to be able to seal the charge transfer body 30, and is a conventionally known sealing material such as a photo-curing resin or a thermosetting resin.

(Production method)
The manufacturing method of the photoelectrode of this invention has the process of carry | supporting an amine compound in an inorganic semiconductor layer with respect to the substrate electrode which has an inorganic semiconductor layer.
The DSC manufacturing method of the present invention includes a step of providing a counter electrode facing the inorganic semiconductor layer of the photoelectrode, and providing a charge transfer body between the photoelectrode and the counter electrode.
Hereinafter, an example of a photoelectrode and a method for manufacturing a DSC will be described with the DSC 1 in FIG. 1 as an example.
The DSC 1 manufacturing method of this example includes a photoelectrode manufacturing process and an assembling process.

<Photoelectrode manufacturing process>
The photoelectrode manufacturing process is a process of obtaining the photoelectrode 10 by supporting an amine compound on the inorganic semiconductor layer 16 of the substrate electrode (supporting operation). That is, the manufacturing method of a photoelectrode has a photoelectrode manufacturing process.

The substrate electrode may be a commercially available electrode or a substrate electrode manufactured by the following method.
A photoelectrode conductive layer 14 is formed on one surface of the photoelectrode support 12. A method for forming the photoelectrode conductive layer 14 is a known method such as a sputtering method or a printing method.
Next, the inorganic semiconductor layer 16 is formed on the photoelectrode conductive layer 14. A method of forming the inorganic semiconductor layer 16 includes a method of spraying particles of a semiconductor material onto the photoelectrode conductive layer 14. A method of spraying particles of a semiconductor material to form the inorganic semiconductor layer 16 is an aerosol position method or the like. For example, a method of forming the inorganic semiconductor layer 16 is a method of forming the inorganic semiconductor layer 16 by applying a paste containing a semiconductor material on the photoelectrode conductive layer 14 and baking the applied paste.

The supporting operation is not limited as long as the amine compound can be supported on the inorganic semiconductor layer 16.
The carrying operation is, for example, the following procedure.
A sensitizing dye and an amine compound are dispersed in a dispersion medium (in particular, sometimes referred to as “dye solution dispersion medium”), and a dye solution for producing a photoelectrode of a dye-sensitized solar cell (hereinafter simply referred to as “dye solution”). To prepare).
The dye solution is brought into contact with the inorganic semiconductor layer 16. The dye solution in contact with the inorganic semiconductor layer 16 penetrates the surface or the inside of the inorganic semiconductor layer 16. After penetrating a desired amount of the dye solution into the inorganic semiconductor layer 16, the dye solution dispersion medium is removed, and the sensitizing dye and the amine compound are supported on the inorganic semiconductor layer 16. Thus, the substrate electrode becomes the photoelectrode 10.

  The method of dispersing the sensitizing dye and the amine compound in the dye solution dispersion medium includes a method of adding the sensitizing dye and the amine compound to the dye solution dispersion medium while stirring the dye solution dispersion medium. The order of adding the sensitizing dye and the amine compound to the dye solution dispersion medium may be the sensitizing dye first, the amine compound first, or a mixture of both.

The dye solution dispersion medium is alcohol, nitrile, ether, ester, ketone, hydrocarbon, halogenated hydrocarbon or the like.
Alcohol is methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, t-butyl alcohol, ethylene glycol, or the like.
Nitriles are acetonitrile, propionitrile, and the like.
The ether is dimethyl ether, diethyl ether, ethyl methyl ether, tetrahydrofuran or the like.
Esters are ethyl acetate, propyl acetate, butyl acetate and the like.
The ketone is acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone or the like.
The hydrocarbon is pentane, hexane, heptane, octane, cyclohexane, toluene, xylene and the like.
The halogenated hydrocarbon is methylene chloride, chloroform or the like.
These dye solution dispersion media may be used alone or in combination of two or more.

  The content of the sensitizing dye with respect to the total volume of the dye solution is preferably 0.1 to 50.0 mmol / L, more preferably 0.2 to 20 mmol / L, and still more preferably 0.3 to 10 mmol / L. If the content of the sensitizing dye is not less than the above lower limit value, the amount of the sensitizing dye supported in the inorganic semiconductor layer 16 can be easily increased. If content of a sensitizing dye is below the said upper limit, it will be easy to disperse | distribute a sensitizing dye to a dye solution.

  The content of the amine compound relative to the total volume of the dye solution is preferably 1.0 to 1000 mg / L, and more preferably 3.5 to 350 mg / L. When the content of the amine compound is equal to or higher than the lower limit, the amount of the amine compound supported in the inorganic semiconductor layer 16 can be easily increased. If the content of the amine compound is not more than the above upper limit value, the amine compound is easily dispersed in the dye solution.

  The content of the amine compound with respect to the total volume of the dye solution is preferably 10 to 5200 mmol / L, and more preferably 15 to 2000 mmol / L. When the content of the amine compound is equal to or higher than the lower limit, the amount of the amine compound supported in the inorganic semiconductor layer 16 can be easily increased. If the content of the amine compound is not more than the above upper limit value, the amine compound is easily dispersed in the dye solution.

  The content of the amine compound in the dye solution is preferably 70 to 3700 mmol, more preferably 170 to 1850 mmol, and still more preferably 340 to 1500 mmol, with respect to 1 mmol of the sensitizing dye supported in the dye solution. If the amount of amine compound supported is not less than the above lower limit, the amount of amine compound supported will be sufficient, and the photoelectric conversion efficiency of DSC 1 can be further improved. If the loading amount of the amine compound is not more than the above upper limit value, the amine compound is less likely to act as an impurity, and the photoelectric conversion efficiency of the DSC 1 can be further improved.

  The method of contacting the dye solution with the inorganic semiconductor layer 16 includes a method of applying the dye solution to the inorganic semiconductor layer 16 (coating method), a method of spraying the dye solution onto the inorganic semiconductor layer 16 (spraying method), and a substrate electrode as the dye solution. And the like (dipping method).

The immersion time in the immersion method is not particularly limited, and is, for example, 0.1 to 200 hours.
The temperature of the dye solution (immersion temperature) in the immersion method can be determined in consideration of the type of the dye solution dispersion medium. The immersion temperature is, for example, 10 to 70 ° C.

The method of removing the dye solution dispersion medium after bringing the dye solution into contact with the inorganic semiconductor layer 16 includes a method of placing the substrate electrode under reduced pressure, a method of heating the substrate electrode, and the like.
The heating temperature for the substrate electrode may be any temperature that can volatilize the dye solution dispersion medium. The heating temperature for the substrate electrode is, for example, 30 to 70 ° C.

  The carrying operation may be a method of carrying the sensitizing dye on the inorganic semiconductor layer 16 and then carrying the amine compound on the inorganic semiconductor layer 16. In the case of this method, a dye solution containing a sensitizing dye and an amine compound solution containing an amine compound are brought into contact with the inorganic semiconductor layer 16 in this order. The content of the sensitizing dye in the dye solution is the same as the content of the sensitizing dye in the dye solution described above. The content of the amine compound in the amine compound solution is the same as the content of the amine compound in the dye solution.

  The supporting operation may be a method in which the amine compound is supported on the inorganic semiconductor layer 16 and then the sensitizing dye is supported on the inorganic semiconductor layer 16. In the case of this method, an amine compound liquid containing an amine compound and a dye liquid containing a sensitizing dye are brought into contact with the inorganic semiconductor layer 16 in this order. The content of the amine compound in the amine compound solution is the same as the content of the amine compound in the dye solution. The content of the sensitizing dye in the dye solution is the same as the content of the sensitizing dye in the dye solution described above.

  Further, for example, a substrate electrode in which a sensitizing dye is previously supported on the inorganic semiconductor layer 16 may be obtained, and an amine compound may be supported on the inorganic semiconductor layer 16 of the substrate electrode.

  The photoelectrode 10 is obtained through the above photoelectrode manufacturing process.

<Assembly process>
The assembly process is a process of obtaining the DSC 1 by incorporating the photoelectrode 10.
The assembly process includes, for example, an operation of providing the counter electrode 20 facing the photoelectrode 10 (electrode arrangement operation) and an operation of providing the charge transfer body 30 between the photoelectrode 10 and the counter electrode 20 (sealing operation). Have.

  The electrode placement operation is an operation in which the inorganic semiconductor layer 16 and the counter electrode conductive layer 24 face each other, and the photoelectrode 10 and the counter electrode 20 are spaced apart from each other.

The sealing operation is an operation of providing the charge transfer body 30 between the photoelectrode 10 and the counter electrode 20. In the sealing operation, for example, the sealing material 40 is provided on the surface of the photoelectrode 10 where the inorganic semiconductor layer 16 is located. Next, the charge transfer body 30 is disposed in a region surrounded by the sealing material 40. The region surrounded by the sealing material 40 is covered with the counter electrode 20, the sealing material 40 is cured, and the charge transfer body 30 is sealed. At this time, the distance between the photoelectrode 10 and the counter electrode 20 can be adjusted by changing the thickness of the sealing material 40.
If necessary, the extraction wiring is connected to the exposed portion 18 and the exposed portion 28.

As described above, in the DSC of the present embodiment, the amine compound is supported on the inorganic semiconductor layer, so that the light conversion efficiency can be further increased.
Although the principle of this embodiment is not clear, it is estimated as follows.
DSC is a reverse electron reaction that causes a drop in voltage or current. The reverse electron reaction is a phenomenon in which electrons leak from the inorganic semiconductor layer to the charge transfer body. In many cases, the dye is adsorbed on the surface of the inorganic semiconductor layer. Since the sensitizing dye is bulky, a gap is formed between the supported sensitizing dyes. For this reason, the supporting electrolyte in the charge transfer member enters between the sensitizing dyes, and the supporting electrolyte comes into contact with the inorganic semiconductor layer to cause a reverse electron reaction.
When the amine compound is supported on the inorganic semiconductor layer, the amine compound penetrates into the gaps between the sensitizing dyes, and the amine compound covers the inorganic semiconductor layer. For this reason, the reverse electron reaction in DSC is hard to occur, and the photoelectric conversion efficiency of DSC can be further improved.

The present invention is not limited to the above-described embodiment.
In the above-mentioned embodiment, it has one area | region (cell) enclosed with the sealing material. The present invention is not limited to this, and a DSC unit in which two or more DSCs are connected in parallel or in series may be formed.

  In the above-described embodiment, no member is provided on the counter electrode conductive layer. This invention is not limited to this, A catalyst layer may be located on a counter electrode conductive layer. The catalyst layer is made of molybdenum, an alloy of molybdenum and another metal, or the like. Examples of the alloy of molybdenum and other metals include an alloy of molybdenum and titanium, an alloy of molybdenum and tungsten, an alloy of molybdenum and yttrium, an alloy of molybdenum and niobium, and the like.

In the above-described embodiment, the photoelectrode has a photoelectrode support. The present invention is not limited to this, and the photoelectrode may not have a photoelectrode support.
In the above-described embodiment, the counter electrode has a counter electrode support. The present invention is not limited to this, and the counter electrode may not have the counter electrode support.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited only to these examples.

(Raw material)
<Sensitizing dye>
N719: sensitizing dye N719, manufactured by Aldrich.
N3: sensitizing dye N3, manufactured by Aldrich.
<Amine compound>
-TBA: Tributylamine, manufactured by Tokyo Chemical Industry Co., Ltd.
-TPA: Tripropylamine, manufactured by Tokyo Chemical Industry Co., Ltd.
CHA: cyclohexylamine, manufactured by Tokyo Chemical Industry Co., Ltd.
<Dye solution dispersion medium>
-B / A: t-butyl alcohol: acetonitrile (volume ratio) = 1: 1 mixed solution.
DMSO: dimethyl sulfoxide.

(Substrate electrode)
A substrate on which a transparent conductive layer (photoelectrode conductive layer, FTO) is located on a glass plate was used. A titanium oxide paste (manufactured by Solaronics; T / SP) was applied on the transparent conductive layer of the substrate by a screen printing method. The applied titanium oxide paste was heat-treated twice. The heat treatment was performed in the order of 200 ° C. for 10 minutes, 200 ° C. for 10 minutes, 500 ° C. for 15 minutes, and 500 ° C. for 30 minutes. The processing environment for the heat treatment was a nitrogen atmosphere and atmospheric pressure. Thus, a substrate electrode in which the inorganic semiconductor layer was located on the transparent conductive layer was obtained. The thickness of the inorganic semiconductor layer was 10 μm.

(Examples 1-7, Comparative Examples 1-5)
According to the composition shown in Table 1, a sensitizing dye and an amine compound were dispersed in a dye solution dispersion medium described in the table to prepare a dye solution.
The substrate electrode was immersed in the dye solution. The immersion time was 18 hours. The immersion temperature was room temperature. Thereafter, the substrate electrode was removed from the dye solution, and the substrate electrode was washed with a dye solution dispersion medium. The washed substrate electrode was dried to obtain a photoelectrode (supporting operation).
For the photoelectrode of each example, the amount of amine compound supported in the inorganic semiconductor layer was measured, and the results are shown in the table.
In addition, "-" of the column of content in a table | surface means that the corresponding raw material is not mix | blended.

A silicon rubber frame having a thickness of 30 μm was provided as a spacer around the inorganic semiconductor layer in the photoelectrode of each example. Into the frame of the spacer, an electrolytic solution (manufactured by Solaronics; Iodolyte 50) was injected as a charge transfer body. A counter electrode was stacked on the electrolyte. The counter electrode was a glass with a platinum coating (counter electrode conductive layer). The photoelectrode and the counter electrode were pressure bonded with a double clip to obtain a DSC simple cell (assembly process). The effective area was 4 mm square.
About the obtained simple cell, photoelectric conversion efficiency was measured and the result is shown in a table | surface.

(Measuring method)
<Adsorption amount of amine compound in inorganic semiconductor layer>
The inorganic semiconductor layer of the photoelectrode in each example was thoroughly washed with acetonitrile. Thereafter, the photoelectrode was immersed in methanol for 2 hours. The components eluted in methanol were concentrated and then fixed with methanol to prepare a measurement sample. About the measurement sample, the adsorption amount of the amine compound was quantified by the multi-inspection method using a liquid chromatograph / mass spectrometry (liquid chromatograph: Agilent Technologies 1200 type, mass analysis: Agilent Technologies 6100 type).

<Adsorption amount of sensitizing dye in inorganic semiconductor layer>
The inorganic semiconductor layer of the photoelectrode in each example was thoroughly washed with acetonitrile. Thereafter, the photoelectrode was immersed in a constant volume of 0.1 mol / L potassium hydroxide solution. The detachment of the sensitizing dye from the inorganic semiconductor layer was visually confirmed, and this was used as a measurement sample. The absorbance of the measurement sample was measured, and the sensitizing dye was quantified by the multi-check calibration method. The amount of amine compound supported determined in “<Amount of amine compound adsorbed in inorganic semiconductor layer>” is converted into moles, and the amount of amine compound supported (mmol) is divided by the amount of adsorbed dye (mmol) to give an amine. The loading ratio (molar ratio) represented by the compound / sensitizing dye was calculated.

<Photoelectric conversion efficiency>
With an evaluation device connected to a solar simulator and an IV characteristic measurement device, the output of 200 lux of light in the simple cell of each example was measured. The efficiency increase rate was calculated by the following equation (1). According to the following evaluation criteria, efficiency increase rates were classified and photoelectric conversion efficiency was evaluated.
Efficiency increase rate (%) = [output of each example] ÷ [output of comparative example 1] × 100 (1)
If the efficiency increase rate was 110% or more, it was judged that the efficiency was clearly increasing.
≪Evaluation criteria≫
O: Efficiency increase rate is 110% or more.
X: Efficiency increase rate is less than 110%.

As shown in Table 1, in Examples 1 to 7 to which the present invention was applied, the photoelectric conversion efficiency was 110% or more. In Comparative Examples 2 to 5, in which the amount of the amine compound supported in the inorganic semiconductor layer was outside the range of the present invention, the photoelectric conversion efficiency was less than 110%.
From these results, it was confirmed that the photoelectric conversion efficiency could be further increased by applying the present invention.

DESCRIPTION OF SYMBOLS 1 Dye-sensitized solar cell, 10 photoelectrode, 14 photoelectrode conductive layer, 16 inorganic semiconductor layer, 20 counter electrode, 30 charge transfer body, 40 sealing material

Claims (12)

Containing a conductive layer, an inorganic semiconductor layer located on the conductive layer, and a sensitizing dye and an amine compound carried on the inorganic semiconductor layer,
The amine compound is at least one selected from aliphatic amines and alicyclic amines,
The photoelectrode whose loading of the said amine compound with respect to the said inorganic-semiconductor layer is 0.2-5.0 mg / cm < ³ >.   The photoelectrode according to claim 1, wherein the amount of the amine compound supported on the inorganic semiconductor layer is 70 to 3700 mmol with respect to 1 mmol of the sensitizing dye.   3. A dye-sensitized solar cell, comprising: the photoelectrode according to claim 1; a counter electrode facing the photoelectrode; and a charge transfer body positioned between the photoelectrode and the counter electrode. Containing a sensitizing dye and at least one amine compound selected from aliphatic amines and alicyclic amines,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume,
Content of the said amine compound is 1.0-1000 mg / L with respect to a total volume, The dye solution for photoelectrode manufacture of a dye-sensitized solar cell. Containing a sensitizing dye and at least one amine compound selected from aliphatic amines and alicyclic amines,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume,
Content of the said amine compound is 10-5200 mmol / L with respect to a total volume, The dye solution for photoelectrode manufacture of a dye-sensitized solar cell.   The dye solution for producing a photoelectrode of a dye-sensitized solar cell according to claim 4 or 5, wherein the content of the amine compound is 70 to 3700 mmol with respect to 1 mmol of the sensitizing dye. A sensitizing dye and at least one amine compound selected from an aliphatic amine and an alicyclic amine are supported on the inorganic semiconductor layer located on the conductive layer, and the amount of the amine compound supported on the inorganic semiconductor layer is 0. A method for producing a photoelectrode, wherein a photoelectrode having a thickness of 2 to 5.0 mg / cm ³ is obtained.   The manufacturing method of the photoelectrode of Claim 7 which makes the pigment | dye solution containing the said amine compound contact the said inorganic semiconductor layer, and carry | supports the said amine compound on the said inorganic semiconductor layer. The dye solution contains the sensitizing dye and the amine compound,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L in the total volume of the dye solution,
The method for producing a photoelectrode according to claim 8, wherein the content of the amine compound is 1.0 to 1000 mg / L in the total volume of the dye solution. The dye solution contains the sensitizing dye and the amine compound,
The content of the sensitizing dye is 0.1 to 50.0 mmol / L with respect to the total volume of the dye solution,
The photoelectrode manufacturing method according to claim 8, wherein the content of the amine compound is 10 to 5200 mmol / L with respect to the total volume of the dye solution. The dye solution contains the sensitizing dye and the amine compound,
The method for producing a photoelectrode according to any one of claims 8 to 10, wherein the content of the amine compound in the dye solution is 70 to 3700 mmol with respect to 1 mmol of the sensitizing dye.   A photoelectrode is obtained by the method for producing a photoelectrode according to any one of claims 7 to 11, a counter electrode facing the inorganic semiconductor layer of the photoelectrode is provided, and the photoelectrode and the counter electrode A method for producing a dye-sensitized solar cell, in which a charge transfer body is provided between the two.

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