JP2016082003A - Method for manufacturing thin film solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thin-film solar battery, by which a thin-film solar battery high in photoelectric conversion efficiency and superior in endurance can be manufactured.SOLUTION: A method for manufacturing a thin-film solar battery including a laminate covered by a sealing layer, provided that the laminate has a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first and second electrodes and including an organic inorganic perovskite compound expressed by the general formula, R-M-X(where R represents an organic molecule, M represents a metal atom, and X represents a halogen atom or chalcogen atom) comprises: a process for performing steps after the step of forming the photoelectric conversion layer until the step of covering the laminate with the sealing layer under an environment of a humidity is 40% or below with a degree of cleanness of 10000 or below.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a thin film solar cell having high photoelectric conversion efficiency and excellent durability.

Conventionally, a photoelectric conversion element in which a plurality of types of semiconductors are stacked and electrodes are provided on both surfaces of the stacked body has been developed. In addition, the use of a composite film in which a plurality of types of semiconductors are combined has been studied instead of such a laminate. In such a photoelectric conversion element, each semiconductor functions as a P-type semiconductor or an N-type semiconductor, photocarriers (electron-hole pairs) are generated in the P-type semiconductor or the N-type semiconductor by photoexcitation, and electrons form the N-type semiconductor. As the holes move through the P-type semiconductor, an electric field is generated.

Currently, most of the photoelectric conversion elements in practical use are inorganic solar cells manufactured using an inorganic semiconductor such as silicon. However, inorganic solar cells are expensive to manufacture and are difficult to increase in size. In addition, the use range of inorganic solar cells may be limited due to low shape following ability, and organic solar cells manufactured using organic semiconductors instead of inorganic semiconductors are attracting attention.

In an organic solar battery, a sealing resin such as a sealing material is used to protect a laminated body in which an N-type semiconductor and a P-type semiconductor are arranged between opposing electrodes from the outside environment and obtain sufficient durability. In general, sealing is performed. In organic solar cells, fullerene is almost always used as a semiconductor material (see, for example, Patent Document 1). Fullerenes are known to work mainly as N-type semiconductors. For example, Patent Document 1 describes a semiconductor heterojunction film formed using an organic compound that becomes a P-type semiconductor and fullerenes.
However, from the viewpoint of recent energy demand, there is a demand for an organic solar cell having higher photoelectric conversion efficiency and sufficient durability.

JP 2006-344794 A

An object of this invention is to provide the manufacturing method of the thin film solar cell which can manufacture the thin film solar cell with high photoelectric conversion efficiency and excellent in durability.

The present invention relates to a general formula R-M-X ₃ (where R is an organic molecule) disposed between a first electrode, a second electrode, and the first electrode and the second electrode. , M represents a metal atom, and X represents a halogen atom or a chalcogen atom) and a photoelectric conversion layer containing an organic-inorganic perovskite compound, and a method for producing a thin film solar cell covered with a sealing layer The method for manufacturing a thin-film solar cell includes a step of performing at least the formation of the photoelectric conversion layer and covering the stacked body with the sealing layer in an environment having a humidity of 40% or less and a cleanness of 10,000 or less. It is.
The present invention is described in detail below.

The inventors of the present invention provide a sealing layer that includes a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. In the covered thin film solar cell, the semiconductor material of the photoelectric conversion layer is represented by the general formula RM-X ₃ (where R represents an organic molecule, M represents a metal atom, and X represents a halogen atom or a chalcogen atom). The use of the organic-inorganic perovskite compounds represented was investigated. By using such an organic-inorganic perovskite compound, an improvement in photoelectric conversion efficiency of the thin film solar cell can be expected.
However, even when the organic / inorganic perovskite compound is used, sufficient photoelectric conversion efficiency and durability cannot be obtained depending on the production environment. On the other hand, the present inventors perform at least the formation of the photoelectric conversion layer and the covering of the stacked body with the sealing layer in a specific environment with a humidity of 40% or less and a cleanness of 10,000 or less. It has been found that by performing the process, a thin film solar cell having high photoelectric conversion efficiency and excellent durability can be obtained.

The method of manufacturing a thin film solar cell of the present invention includes a first electrode, a second electrode and the general formula R-M-X ₃ which are disposed between the first electrode and the second electrode ( Here, R is an organic molecule, M is a metal atom, X is a halogen atom or a chalcogen atom), and a laminate having a photoelectric conversion layer containing an organic-inorganic perovskite compound is covered with a sealing layer. It is a method of manufacturing a thin film solar cell.
In the present specification, the layer or part means not only a layer or part having a clear boundary but also a layer or part having a concentration gradient in which the contained element gradually changes. In addition, the elemental analysis of a layer or a site | part can be performed by performing the FE-TEM / EDS ray analysis measurement of the cross section of a thin film solar cell, for example, and confirming the element distribution of a specific element. In addition, in this specification, a layer or a part means not only a flat thin film layer or part, but also a layer or part that can form a complicated structure together with another layer or part. To do.

The materials for the first electrode and the second electrode are not particularly limited, and conventionally known materials can be used.
As the first electrode material, for example, FTO (fluorine-doped tin oxide), sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al ₂ O ₃ mixture, Al / LiF mixture, etc. are mentioned. Examples of the second electrode material include metals such as gold, CuI, ITO (indium tin oxide), SnO ₂ , AZO (aluminum zinc oxide), IZO (indium zinc oxide), and GZO (gallium zinc oxide). Conductive transparent materials such as, conductive transparent polymers and the like. These materials may be used alone or in combination of two or more.

The photoelectric conversion layer includes an organic inorganic perovskite compound represented by the general formula R-M-X ₃ (where R represents an organic molecule, M represents a metal atom, and X represents a halogen atom or a chalcogen atom).
Incidentally, it refers to a site containing the general formula organic-inorganic perovskite compound represented by R-M-X _3, hereinafter, to as organic-inorganic perovskite compound sites.

By using the organic / inorganic perovskite compound, the thin film solar cell obtained by the method for manufacturing a thin film solar cell of the present invention can be made excellent in photoelectric conversion efficiency because of its very high charge separation efficiency. In addition, organic inorganic perovskite compounds having excellent flexibility and impact resistance of organic materials and durability and heat resistance of inorganic materials are excellent in durability, and thus can be obtained by the method for manufacturing a thin film solar cell of the present invention. Thin film solar cells also have excellent durability.

The organic / inorganic perovskite compound is preferably a crystalline compound. The crystalline compound means a compound capable of measuring the X-ray scattering intensity distribution and detecting a scattering peak. When the organic / inorganic perovskite compound is a crystalline compound, the mobility of electrons is increased, and the photoelectric conversion efficiency is improved.
In addition, the degree of crystallization can be evaluated as an index of crystallization. Crystallinity refers to the separation of the crystalline-derived scattering peak and the amorphous-derived halo detected by X-ray scattering intensity distribution measurement by fitting, and obtaining the respective intensity integrals to obtain the crystalline portion of the whole. Can be obtained by calculating the ratio. The minimum of the preferable crystallinity degree of the said organic inorganic perovskite compound is 30%. When the crystallinity is 30% or more, the mobility of electrons increases and the photoelectric conversion efficiency increases. A more preferred lower limit of crystallinity is 50%, and a more preferred lower limit is 70%.
Examples of a method for increasing the crystallinity of the organic / inorganic perovskite compound include thermal annealing, irradiation with intense light such as laser, and plasma irradiation.

The organic / inorganic perovskite compound contains a halogen. By containing halogen in the structure, the organic / inorganic perovskite compound becomes soluble in an organic solvent and can be applied to an inexpensive printing method.
Furthermore, the organic inorganic perovskite compound is represented by the general formula R-M-X ₃ . Here, R is an organic molecule, M is a metal atom, and X is a halogen atom or a chalcogen atom. When the organic inorganic perovskite compound is represented by the general formula R-M-X ₃ , a cubic system in which a metal atom M is arranged at the body center, an organic molecule R is arranged at each vertex, and a halogen atom or a chalcogen atom X is arranged at the face center. It is preferable to have the following structure. FIG. 1 shows a cubic structure in which a metal atom M is arranged in the body center, an organic molecule R is arranged at each vertex, and a halogen atom or a chalcogen atom X is arranged in the face center. Although details are not clear, since the orientation of the octahedron in the crystal lattice can be easily changed by having the above structure, the electron mobility becomes high, so that high photoelectric conversion efficiency can be realized. It is estimated to be.

In the general formula R-M-X ₃ of the organic inorganic perovskite compound, R is an organic molecule and is a molecule represented by C ₁ N _m X _n (l, m and n are all positive integers). preferable. R is specifically methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, dimethylamine, dipropylamine dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine , Tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, azetidine, azeto, Azole, imidazoline, carbazole and their ions (eg, methylammonium (CH ₃ NH ₃ ), etc.) and phenethylammoni Um etc. are mentioned. Of these, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine and their ions and phenethylammonium are preferred, and methylamine, ethylamine, propylamine and these ions are more preferred.

M is a metal atom, such as lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, europium, etc. Can be mentioned. These elements may be used independently and 2 or more types may be used together. X is a halogen atom or a chalcogen atom, and examples thereof include chlorine, bromine, iodine, sulfur, and selenium. These elements may be used independently and 2 or more types may be used together. Among these, the halogen atom is preferable because the organic / inorganic perovskite compound becomes soluble in an organic solvent and can be applied to an inexpensive printing method by containing halogen in the structure. Furthermore, iodine is more preferable because the energy band gap of the organic-inorganic perovskite compound becomes narrow.

The photoelectric conversion layer may further contain an organic semiconductor or an inorganic semiconductor in addition to the organic / inorganic perovskite compound as long as the effects of the present invention are not impaired. Note that the organic semiconductor or inorganic semiconductor here may serve as an electron transport layer or a hole transport layer described later.
Examples of the organic semiconductor include compounds having a thiophene skeleton such as poly (3-alkylthiophene). In addition, for example, conductive polymers having a polyparaphenylene vinylene skeleton, a polyvinyl carbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton, and the like can be given. Further, for example, compounds having a porphyrin skeleton such as a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, or a benzoporphyrin skeleton, a spirobifluorene skeleton, etc., and carbon-containing materials such as carbon nanotubes, graphene, and fullerene that may be surface-modified Also mentioned.

Examples of the inorganic semiconductor include titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, CuSCN, Cu ₂ O, CuI, MoO ₃ , V ₂ O ₅ , WO ₃ , _{MoS 2, MoSe 2, Cu 2} S , and the like.

When the photoelectric conversion layer includes the organic semiconductor or the inorganic semiconductor, the photoelectric conversion layer may be a thin film organic semiconductor or a laminated body in which an inorganic semiconductor portion and a thin organic inorganic perovskite compound portion are laminated, or an organic semiconductor Alternatively, a composite film in which an inorganic semiconductor site and an organic / inorganic perovskite compound site are combined may be used. A laminated body is preferable in that the production method is simple, and a composite film is preferable in that the charge separation efficiency in the organic semiconductor or the inorganic semiconductor can be improved.

The preferable lower limit of the thickness of the thin-film organic / inorganic perovskite compound site is 5 nm, and the preferable upper limit is 5000 nm. If the thickness is 5 nm or more, light can be sufficiently absorbed, and the photoelectric conversion efficiency is increased. If the said thickness is 5000 nm or less, since it can suppress that the area | region which cannot carry out charge separation generate | occur | produces, it will lead to the improvement of photoelectric conversion efficiency. The more preferable lower limit of the thickness is 10 nm, the more preferable upper limit is 1000 nm, the still more preferable lower limit is 20 nm, and the still more preferable upper limit is 500 nm.

When the photoelectric conversion layer is a composite film in which an organic semiconductor or an inorganic semiconductor part and an organic / inorganic perovskite compound part are combined, a preferable lower limit of the thickness of the composite film is 30 nm, and a preferable upper limit is 3000 nm. If the thickness is 30 nm or more, light can be sufficiently absorbed, and the photoelectric conversion efficiency is increased. If the said thickness is 3000 nm or less, since it becomes easy to reach | attain an electrode, a photoelectric conversion efficiency becomes high. The more preferable lower limit of the thickness is 40 nm, the more preferable upper limit is 2000 nm, the still more preferable lower limit is 50 nm, and the still more preferable upper limit is 1000 nm.

The method for producing a thin film solar cell of the present invention includes a laminate having the first electrode, the second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. However, as long as the thin film solar cell covered with the sealing layer can be manufactured, any process may be included.
Specifically, for example, the method for producing a thin film solar cell of the present invention includes the step of forming the first electrode, the step of forming the photoelectric conversion layer, the step of forming the second electrode, and the obtained laminate. A step of covering the body (solar cell) with a sealing layer in this order, a step of forming the second electrode, a step of forming the photoelectric conversion layer, and the first electrode You may have the process of forming and the process of covering the obtained laminated body (solar cell) with the sealing layer in this order.

The method of forming the first electrode is not particularly limited. For example, when the first electrode is made of FTO (fluorine-doped tin oxide), a method of forming an FTO film on the substrate by the SPD method or the like can be given. It is done. The said board | substrate is not specifically limited, For example, transparent glass substrates, such as soda-lime glass and an alkali free glass, a ceramic substrate, a transparent plastic substrate, metal foil, etc. are mentioned.
Moreover, you may use what the said 1st electrode was previously formed on the said board | substrate (for example, FTO glass substrate).

The method for forming the photoelectric conversion layer is not particularly limited, and examples thereof include a vacuum deposition method, a sputtering method, a gas phase reaction method (CVD), an electrochemical deposition method, and a printing method. Especially, the thin film solar cell which can exhibit high photoelectric conversion efficiency can be easily formed in a large area by employ | adopting a printing method. Examples of the printing method include a spin coating method and a casting method, and examples of a method using the printing method include a roll-to-roll method.
As a method for forming the photoelectric conversion layer, specifically, for example, an organic / inorganic perovskite compound forming solution (that is, an organic / inorganic perovskite compound) is formed on the first electrode or an electron transport layer formed as necessary. For example, a method of forming the thin-film organic semiconductor portion on the thin-film organic-inorganic perovskite compound portion, and the like. .

The method for forming the second electrode is not particularly limited. For example, when the second electrode is made of a metal such as gold, on the photoelectric conversion layer or on the hole transport layer formed as necessary, Examples thereof include a method of forming a metal film such as gold by vapor deposition or the like.

The manufacturing method of the thin film solar cell of this invention may have the process of forming an electron carrying layer between said 1st electrode and said photoelectric conversion layer.
The material of the electron transport layer is not particularly limited. For example, N-type conductive polymer, N-type low molecular organic semiconductor, N-type metal oxide, N-type metal sulfide, alkali metal halide, alkali metal, surface activity Specific examples include, for example, cyano group-containing polyphenylene vinylene, boron-containing polymer, bathocuproine, bathophenanthrene, hydroxyquinolinato aluminum, oxadiazole compound, benzimidazole compound, naphthalene tetracarboxylic acid compound, perylene derivative, Examples include phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, and zinc sulfide.

The preferable lower limit of the thickness of the electron transport layer is 1 nm, and the preferable upper limit is 2000 nm. If the thickness is 1 nm or more, holes can be sufficiently blocked. If the said thickness is 2000 nm or less, it will become difficult to become resistance at the time of electron transport, and photoelectric conversion efficiency will become high. The more preferable lower limit of the thickness of the electron transport layer is 3 nm, and the more preferable upper limit is 1000 nm.

The method for forming the electron transport layer is not particularly limited. For example, in the case of forming an electron transport layer made of titanium oxide, a thin film is formed by applying a coating liquid containing titanium on the first electrode and then baking it. A porous electron transport layer is formed by applying a titanium oxide paste containing an organic binder and titanium oxide particles on the thin film electron transport layer, followed by baking. And the like.

The method for producing a thin-film solar cell of the present invention may include a step of forming a hole transport layer between the second electrode and the photoelectric conversion layer.
The material of the hole transport layer is not particularly limited, and examples thereof include a P-type conductive polymer, a P-type low molecular organic semiconductor, a P-type metal oxide, a P-type metal sulfide, and a surfactant. Examples include polystyrene sulfonate adduct of polyethylenedioxythiophene, carboxyl group-containing polythiophene, phthalocyanine, porphyrin, molybdenum oxide, vanadium oxide, tungsten oxide, nickel oxide, copper oxide, tin oxide, molybdenum sulfide, tungsten sulfide, copper sulfide. , Tin sulfide and the like, fluoro group-containing phosphonic acid, carbonyl group-containing phosphonic acid and the like.

The preferable lower limit of the thickness of the hole transport layer is 1 nm, and the preferable upper limit is 2000 nm. If the thickness is 1 nm or more, electrons can be sufficiently blocked. If the said thickness is 2000 nm or less, it will become difficult to become resistance at the time of hole transport, and a photoelectric conversion efficiency will become high. The more preferable lower limit of the thickness is 3 nm, the more preferable upper limit is 1000 nm, the still more preferable lower limit is 5 nm, and the still more preferable upper limit is 500 nm.

The method of forming the hole transport layer is not particularly limited. For example, a method of applying a solution in which a hole transport material is dissolved in an organic solvent and then volatilizing the organic solvent, a method of vacuum film formation such as vapor deposition or sputtering. Etc.

By carrying out the step of covering the laminate with a sealing layer, the laminate can be protected from the outside environment and sufficient durability can be obtained, and the thin film solar with higher photoelectric conversion efficiency and higher durability A battery can be obtained.

The material used for the sealing layer is not particularly limited, and a known material can be used, which may be an organic material or an inorganic material. That is, the sealing layer may include an organic sealing layer made of an organic material or an inorganic sealing layer made of an inorganic material. Furthermore, the sealing layer preferably includes both an organic sealing layer and an inorganic sealing layer.
Examples of the organic material include a curable resin and a hot melt resin. Examples of the inorganic material include inorganic oxides, inorganic nitrides, inorganic sulfides, and the like, and silicone resins having an organic group may be used. Specific examples include silicon oxide, tin oxide, zirconium oxide, magnesium oxide, composite oxide aluminum nitride composed of a plurality of metals, and silicon nitride. Especially, since it is excellent in gas barrier property and can improve durability of a thin film solar cell, the sealing layer includes an inorganic sealing layer, and the inorganic sealing layer is made of an inorganic oxide or an inorganic nitride. Is preferred.

The method for forming the sealing layer is not particularly limited, and examples thereof include a printing method such as dispensing and screen printing if the material used for the sealing layer is an organic material. If the material used for the sealing layer is an inorganic material, sputtering, vapor deposition, and the like can be given.
Specific examples of the method of forming the sealing layer include a method of forming the sealing layer on the second electrode of the laminate so as to cover the entire laminate. . When formed in order from the first electrode, the sealing layer is formed on the second electrode. The first electrode may be a cathode or an anode, and the second electrode may be an anode or a cathode.

The preferable lower limit of the thickness of the organic sealing layer is 100 nm, and the preferable upper limit is 100000 nm. When the thickness is 100 nm or more, the laminate can be sufficiently covered by the organic sealing layer. When the thickness is 100000 nm or less, the organic sealing layer can sufficiently block water vapor entering from the side surface. A more preferable lower limit of the thickness is 500 nm, a more preferable upper limit is 50000 nm, a still more preferable lower limit is 1000 nm, and a still more preferable upper limit is 20000 nm.

The preferable lower limit of the thickness of the inorganic sealing layer is 30 nm, and the preferable upper limit is 3000 nm. If the said thickness is 30 nm or more, the said inorganic sealing layer can have sufficient water vapor | steam barrier property, and durability of a thin film solar cell improves. If the thickness is 3000 nm or less, even if the thickness of the inorganic sealing layer is increased, the generated stress is small, so that the peeling of the inorganic sealing layer, the electrode, the semiconductor layer, etc. can be suppressed. it can. The more preferable lower limit of the thickness is 50 nm, the more preferable upper limit is 1000 nm, the still more preferable lower limit is 100 nm, and the still more preferable upper limit is 500 nm.
In addition, the thickness of the inorganic sealing layer can be measured using an optical film thickness measuring device (for example, FE-3000 manufactured by Otsuka Electronics Co., Ltd.).

The method for producing a thin-film solar cell of the present invention includes a step of performing at least a photoelectric conversion layer and covering the laminate with the sealing layer in an environment having a humidity of 40% or less and a cleanness of 10,000 or less. Including. By performing a process of forming at least the photoelectric conversion layer under the above conditions and covering the laminate with the sealing layer, a thin film solar cell having high photoelectric conversion efficiency and excellent durability is obtained. Can do.

Since the organic-inorganic perovskite compound can exist stably when the humidity is 40% or less, the initial conversion efficiency of the thin-film solar cell can be increased. The preferred humidity is 35% or less, more preferably 30% or less. The humidity can be measured from the temperature difference between the dry bulb temperature and the wet bulb temperature.

Furthermore, since the said 2nd electrode can cover the said photoelectric converting layer without gap as the said cleanliness is 10000 or less, durability of a thin film solar cell can be improved. When the cleanliness is 10,000 or less, the sealing layer is disposed between the first electrode, the second electrode, and the first electrode and the second electrode. Since the laminated body (solar cell) having the photoelectric conversion layer can be covered without a gap, the durability of the thin film solar cell can be improved. The cleanliness is preferably 5000 or less, more preferably 2000 or less. The cleanness can be measured using a particle counter (for example, KC-51, manufactured by Rion Co., Ltd.), and represents the number of dust per 1 m ³ .

An example of the thin film solar cell obtained by the manufacturing method of the thin film solar cell of this invention is typically shown in FIG. The thin film solar cell 1 shown in FIG. 2 includes a substrate 7, a transparent electrode (first electrode) 2, a layer 4 including a porous electron transport layer portion, an organic / inorganic perovskite compound portion, and an organic semiconductor portion, an electrode (second electrode). Electrode) 3, an organic sealing layer 5, and an inorganic sealing layer 6, of which a preferred lower limit of the film thickness of the layer 4 including a porous electron transport site, an organic / inorganic perovskite compound site, and an organic semiconductor site Is 50 nm, and the preferred upper limit is 5 μm. When the film thickness is 50 nm or more, photoelectric conversion efficiency is increased by sufficiently absorbing light. When the film thickness is 5 μm or less, the generated charges are easily collected efficiently by the electrode, and the photoelectric conversion efficiency is increased. The more preferable lower limit of the film thickness is 100 nm, and the more preferable upper limit is 2 μm.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the thin film solar cell with high photoelectric conversion efficiency and excellent durability can be provided.

It is a schematic diagram which shows an example of the crystal structure of an organic inorganic perovskite compound. It is sectional drawing which shows typically an example of the thin film solar cell obtained by the manufacturing method of the thin film solar cell of this invention.

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

Example 1
The following series of operations was performed in a room with a humidity of 25% and a cleanness of 1000.

(Production of thin film solar cells)
A titanium isopropoxide ethanol solution adjusted to 2% was applied on the surface of the FTO film by a spin coating method, followed by baking at 400 ° C. for 10 minutes to form an electron transport layer having a thickness of 20 nm. Further, a titanium oxide paste containing polyisobutyl methacrylate as an organic binder and titanium oxide (a mixture of average particle diameters of 10 nm and 30 nm) is laminated on the thin film-shaped electron transport layer by the same spin coat method, and is heated to 500 ° C. Was fired for 10 minutes to form a porous electron transport layer having a thickness of 500 nm.
Subsequently, CH ₃ NH ₃ I and PbI ₂ are dissolved in a molar ratio of 1: 1 using N, N-dimethylformamide (DMF) as a solvent as a solution for forming an organic inorganic perovskite compound, and the total weight of CH ₃ NH ₃ I and PbI ₂ The concentration was adjusted to 20%. This solution was laminated on the electron transport layer by spin coating. Further, a solution obtained by dissolving Spiro-OMeTAD (having a spirobifluorene skeleton) in 68 mM, tert-butylpyridine in 55 mM, and Lithium Bis (trifluoromethylsulfonyl) imide salt in a thickness of 300 nm by spin coating in 25 μL of chlorobenzene was spin-coated. A photoelectric conversion layer was formed.
On the photoelectric conversion layer, a gold film having a thickness of 100 nm was formed as an anode by vacuum deposition. Thereby, an electron transport layer (including a thin-film electron transport layer and a porous electron transport layer) and a photoelectric conversion layer (including an organic / inorganic perovskite compound portion and an organic semiconductor portion) are formed on the surface of the FTO film. The laminated body which has was obtained.
The obtained laminate was attached to a substrate holder of a sputtering apparatus, and a ZnSn alloy (Zn: Sn = 95: 5 wt%) target was attached to the cathode A of the sputtering apparatus, and an Si target was attached to the cathode B. The film forming chamber of the sputtering apparatus was evacuated by a vacuum pump, and the pressure was reduced to 5.0 × 10 ⁻⁴ Pa. Thereafter, sputtering was performed under the conditions shown in film formation condition A, and a SiZnSnO thin film was formed as an inorganic film (sealing layer) on the laminate (perovskite solar battery cell) to obtain a thin film solar battery.
(Film formation condition A)
Argon gas flow rate: 50 sccm, oxygen gas flow rate: 50 sccm
Power output: Cathode A = 500W, Cathode B = 1500W

(Examples 2 to 10, Comparative Examples 1 to 5)
A thin-film solar cell was obtained in the same manner as in Example 1 except that the operation was performed with the humidity and cleanliness set to the conditions shown in Table 1, and the organic / inorganic perovskite compound was changed as shown in Table 1. .
In Example 7, CH ₃ NH ₃ Br, CH ₃ NH ₃ I, PbBr ₂ and PbI ₂ were dissolved at a molar ratio of 1: 2: 1: 2 using N, N-dimethylformamide (DMF) as a solvent. In Example 8, CH ₃ NH ₃ I and PbCl ₂ were dissolved at a molar ratio of 3: 1 using N, N-dimethylformamide (DMF) as a solvent. In Example 9, CH ₃ NH ₃ Br and PbBr ₂ were dissolved at a molar ratio of 1: 1 using N, N-dimethylformamide (DMF) as a solvent. In Example 10, CH ₃ (NH ₃ ) ₂ I and PbI ₂ were dissolved at a molar ratio of 1: 1 using N, N-dimethylformamide (DMF) as a solvent.

<Evaluation>
The following evaluation was performed about the thin film solar cell obtained by the Example and the comparative example.

(1) Initial conversion efficiency A power source (manufactured by KEITHLEY, 236 model) is connected between the electrodes of the thin film solar cell, and photoelectric conversion efficiency is measured using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) having an intensity of 100 mW / cm ^2. did. The obtained photoelectric conversion efficiency was defined as the initial conversion efficiency. Judgment was performed based on the following criteria.
○: Initial conversion efficiency was not less than the value of Comparative Example 1. ×: Initial conversion efficiency was less than the value of Comparative Example 1.

(2) Durability The thin film solar cell was left at a temperature of 30 ° C. and a humidity of 70% for 24 hours (durability). The photoelectric conversion efficiency before and after the durability test was measured in the same manner as described above. Judgment was performed based on the following criteria.
○: The photoelectric conversion efficiency was 50% or more of the initial conversion efficiency. ×: The photoelectric conversion efficiency was less than 50% of the initial conversion efficiency.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the thin film solar cell which can manufacture the thin film solar cell with high photoelectric conversion efficiency and excellent durability can be provided.

1 Thin-film solar cell 2 Transparent electrode (first electrode)
3 electrodes (second electrode)
4 Layer 5 containing porous electron transport site, organic / inorganic perovskite compound site, and organic semiconductor site 5 Organic sealing layer 6 Inorganic sealing layer 7 Substrate

Claims (3)

A first electrode, a second electrode, and a general formula R-M-X ₃ (where R is an organic molecule and M is a metal) disposed between the first electrode and the second electrode. A laminate having a photoelectric conversion layer containing an organic-inorganic perovskite compound represented by (Atom, X represents a halogen atom or a chalcogen atom), and is a method for producing a thin-film solar cell covered with a sealing layer,
Production of a thin-film solar cell comprising a step of performing at least the photoelectric conversion layer and covering the laminate with the sealing layer in an environment having a humidity of 40% or less and a cleanness of 10,000 or less. Method. The method for manufacturing a thin-film solar cell according to claim 1, wherein the photoelectric conversion layer further contains an organic semiconductor. The method for producing a thin-film solar cell according to claim 1 or 2, wherein the sealing layer includes an inorganic sealing layer, and the inorganic sealing layer is made of an inorganic oxide or an inorganic nitride.

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