Method for manufacturing solar cells, and apparatus for manufacturing solar cells

Abstract

To provide a method for manufacturing perovskite-type solar cells with good performance using various solvents without employing large-scale equipment. [Solution] The method for manufacturing the solar cell comprises at least a photoelectric conversion layer containing a metal halide perovskite compound, an electron transport layer disposed on one side of the photoelectric conversion layer, and a hole transport layer disposed on the other side of the photoelectric conversion layer, and includes the steps of forming a coating film containing the metal halide perovskite compound and / or its raw material and a solvent on the hole transport layer or the electron transport layer, and holding the coating film in an environment of 35°C to 105°C and 100 Pa or less, and removing the solvent to form a crystal precursor layer.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing solar cells and a solar cell manufacturing apparatus used in said manufacturing method. [Background technology]

[0002] Solar cells having a photoelectric conversion layer containing a metal halide perovskite compound are generally also called perovskite solar cells. Many of the layers constituting such perovskite solar cells can be formed by coating methods, etc. Therefore, perovskite solar cells can be manufactured at low cost and easily. Furthermore, they can be manufactured in small areas (1 cm²). 2 Perovskite solar cells of a certain type have been reported to have energy conversion efficiencies exceeding 25%. Therefore, perovskite solar cells are also promising in terms of performance.

[0003] Furthermore, perovskite solar cells allow for easy adjustment of the band gap by changing the composition of the photoelectric conversion layer. Therefore, tandem solar cells, which combine perovskite solar cells with crystalline silicon solar cells, are attracting attention for their ability to utilize sunlight very effectively.

[0004] Perovskite solar cells typically have conductive electrodes / hole transport layer / photoelectric conversion layer / electron transport layer / conductive electrodes in this order. The configuration in which the hole transport layer is positioned on the light incident surface side is called the reverse type, and the configuration in which the electron transport layer is positioned on the light incident surface side is called the forward type.

[0005] Here, the photoelectric conversion layer is obtained by forming a coating film from a solution containing a metal halide perovskite compound and / or its raw material, and a solvent (hereinafter also referred to as "perovskite solution"), removing the solvent from the coating film to form a crystal precursor, and then annealing it under atmospheric pressure. In this specification, the layered state after removing the solvent from the coating film and before annealing is referred to as the crystal precursor layer. Methods for forming the crystal precursor layer include the poor solvent method, the gas quench method, and the vacuum quench method.

[0006] The poor solvent method involves applying the perovskite solution using a spin-coating method, and then adding a poor solvent such as anisole dropwise to the formed coating to promote the crystallization of the metal halide perovskite compound. This poor solvent method is very useful in the fabrication of small-area solar cells, and it is possible to produce solar cells with high conversion efficiency using this method. However, as the size of the substrate increases, it becomes difficult to uniformly apply the perovskite solution using the spin-coating method. Therefore, the poor solvent method has the challenge of being difficult to apply to the manufacture of large-area solar cells.

[0007] The gas quenching method is a technique in which a perovskite solution is applied using a slit coater or similar device, and then air or argon is blown onto it to accelerate the crystallization of the metal halide perovskite compound. The gas quenching method has the advantage of being suitable for the fabrication of large-area solar cells. However, a drawback is that a large amount of solvent is released into the atmosphere because the solvent is rapidly evaporated by blowing on the gas.

[0008] The vacuum quenching method is a method in which a perovskite solution is applied by various methods, and then the coating is rapidly depressurized in a vacuum chamber to promote the crystallization of the metal halide perovskite compound. (For example, Non-Patent Documents 1-3 and Patent Document 1). This vacuum quenching method can also be used for the fabrication of large-area solar cells. In addition, since the solvent is quickly discharged with a vacuum pump, it has the advantage that a large amount of solvent is not easily released into the atmosphere. [Prior art documents]

Patent Document

[0009]

Patent Document 1

Non-Patent Document

[0010]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] However, solar cells obtained by the conventional vacuum quenching method tend to have inferior performance compared to those obtained by the poor solvent method. This is thought to be because the evaporation rate of the solvent affects the crystalline state of the resulting metal halide perovskite compound and, consequently, the performance of the solar cell. In conventionally reported methods for fabricating solar cells using the vacuum quenching method, the solvent is removed from the perovskite solution coating without temperature control. Therefore, if the substrate has a large area or the performance of the vacuum pump (vacuum pumping speed) is low, the evaporation rate of the solvent tends to be slow. As a result, it is thought that the crystallization of the metal halide perovskite compound is not sufficiently promoted, and the performance does not improve sufficiently. Therefore, it is conceivable to ensure a sufficient evaporation rate of the solvent by increasing the exhaust volume of the vacuum pump. However, as the area of ​​the solar cell increases, a larger vacuum pump is required, and the cost also increases. Therefore, there has been a challenge in that this method is difficult to commercialize.

[0012] Furthermore, the vacuum quenching method described above has limitations on the type of solvent that can be used in order to remove the solvent at the desired rate. Conventionally, N,N-dimethylformamide (DMF) (vapor pressure approximately 300 Pa (20°C)), which has a high vapor pressure, has been mainly used as the solvent. In contrast, in recent years, there has been a desire to use solvents that have less impact on the environment and the human body, such as dimethyl sulfoxide (DMSO) (vapor pressure approximately 80 Pa (20°C), approximately 100 Pa (25°C)) and N-methyl-2-pyrrolidone (NMP) (vapor pressure approximately 30 Pa (20°C), approximately 40 Pa (25°C)). However, these solvents have low vapor pressures at room temperature, making them difficult to use unless combined with DMF.

[0013] This invention has been made in view of the above problems. The purpose of this invention is to provide a method for manufacturing perovskite-type solar cells with good performance using various solvents without using large-scale equipment. The invention also provides a solar cell manufacturing apparatus that can be used in this manufacturing method. [Means for solving the problem]

[0014] This invention provides the following method for manufacturing solar cells. [1] A method for manufacturing a solar cell having at least a photoelectric conversion layer containing a metal halide perovskite compound, an electron transport layer disposed on one side of the photoelectric conversion layer, and a hole transport layer disposed on the other side of the photoelectric conversion layer, comprising the steps of forming a coating film containing the metal halide perovskite compound and / or its raw material and a solvent on the hole transport layer or the electron transport layer, and holding the coating film in an environment of 35°C to 105°C and 100 Pa or less, and removing the solvent to form a crystal precursor layer. [2] The method for manufacturing a solar cell according to [1], wherein, in the step of forming the crystal precursor layer, the environment holding the coating film is reduced from atmospheric pressure to 100 Pa or less within 100 seconds. [3] The method for manufacturing a solar cell according to [1] or [2], wherein in the step of forming the crystal precursor layer, the coating film is held for 1 minute or more and 30 minutes or less in an environment of 35°C to 105°C and 100 Pa or less. [4] A method for manufacturing a solar cell according to any one of [1] to [3], further comprising the step of annealing the crystal precursor layer under atmospheric pressure and at a temperature of 50°C to 180°C to form a photoelectric conversion layer.

[0015] The present invention provides the following apparatus for manufacturing solar cells. [5] A solar cell manufacturing apparatus comprising a vacuum chamber, a vacuum mechanism connected to the vacuum chamber for reducing the pressure inside the vacuum chamber, and a temperature control mechanism for adjusting the stage temperature inside the vacuum chamber, wherein the apparatus removes a metal halide perovskite compound and / or its raw materials, as well as a solvent, from a coating film containing the solvent, within the vacuum chamber. [Effects of the Invention]

[0016] According to the present invention, perovskite-type solar cells with good performance can be manufactured using various solvents without the need for large-scale equipment. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic cross-sectional view of a solar cell manufactured by the method according to one embodiment of the present invention. [Figure 2] This is a schematic diagram showing the structure of the manufacturing process for a solar cell relating to one embodiment of the present invention. [Figure 3] This graph shows the relationship between the absorbance of the photoelectric conversion layer fabricated in the example and the sample temperature when forming the crystal precursor layer. [Modes for carrying out the invention]

[0018] The method for manufacturing solar cells and the apparatus for manufacturing solar cells of the present invention will be described using the following embodiments as examples. However, the method for manufacturing solar cells of the present invention and the apparatus for manufacturing solar cells to realize it are not limited to these embodiments.

[0019] 1. Method for manufacturing solar cells Figure 1 shows an example of the structure of a solar cell manufactured in this embodiment. The solar cell 100 has a substrate 10, an anode layer 20, a hole transport layer 30, a photoelectric conversion layer 40, an electron transport layer 50, and a cathode layer 60, and light is incident from the substrate 10 side and / or the cathode layer 61 side.

[0020] The method for manufacturing the solar cell 100 of this embodiment includes at least the steps of forming a coating film containing a metal halide perovskite compound and / or its raw material and a solvent on a hole transport layer 30 laminated with a substrate 10 and an anode layer 20 (hereinafter also referred to as the "coating film formation step"), and the steps of holding the coating film in an environment of 35°C to 105°C and 100 Pa or less to remove the solvent and form a crystal precursor layer (hereinafter also referred to as the "crystal precursor layer formation step"). Typically, the method further includes the step of annealing the crystal precursor layer obtained in the crystal precursor layer formation step (hereinafter also referred to as the "annealing step"). Furthermore, the method for manufacturing the solar cell 100 may include other steps, and may further include steps for forming each layer such as the anode layer 20, hole transport layer 30, electron transport layer 50, and cathode layer 60.

[0021] As described above, when forming a photoelectric conversion layer, the performance of the resulting photoelectric conversion layer tends to be inferior when the crystalline precursor layer is formed using the conventional vacuum quench method compared to when the crystalline precursor layer is formed using the poor solvent method. One of the factors contributing to this is thought to be the formation rate of the crystalline precursor layer (the evaporation rate of the solvent). However, it has been difficult to control the evaporation rate of the solvent using the conventional vacuum quench method. For example, when manufacturing large-area solar cells, a large vacuum pump is required, and it is difficult to use solvents with low vapor pressure.

[0022] In contrast, in the solar cell manufacturing method of this embodiment, in the crystal precursor layer formation step, a coating film containing a metal halide perovskite compound and / or its raw materials, as well as a solvent, is maintained in an environment of 35°C to 105°C and 100 Pa or less. According to this method, it is possible to evaporate the solvent at an appropriate rate without depending on the vacuum pumping speed during the formation of the crystal precursor layer. On the other hand, by setting the heating temperature to 105°C or less, the crystal precursor in the formed crystal precursor layer is less susceptible to heat. Therefore, according to the solar cell manufacturing method including this crystal precursor formation step, solar cells with very good performance can be manufactured, as will be demonstrated in the examples described later. Furthermore, according to this method, the solvent can be evaporated at an appropriate rate whether the area of ​​the solar cell to be manufactured is small or large. Therefore, there is also the advantage that the quality of the resulting solar cell is more easily stabilized.

[0023] Furthermore, this method makes it possible to use solvents that were difficult to use with conventional vacuum quenching methods. Specifically, the vapor pressure of N-methyl-2-pyrrolidone (NMP) is approximately 40 Pa at 25°C, and it was difficult to use with conventional vacuum quenching methods because its evaporation took a long time. On the other hand, the vapor pressure of NMP is approximately 230 Pa at 50°C, which is nearly six times the vapor pressure at 25°C. Therefore, with the method of this embodiment, even when using NMP, its evaporation rate can be kept within an appropriate range. Thus, solvents that were previously difficult to use can be used, and it becomes possible to manufacture solar cells with greater safety and environmental considerations by using various solvents.

[0024] In the following, the photoelectric conversion layer 40 and its formation method will be described first, followed by a description of the other layers and their formation methods.

[0025] (Photoelectric conversion layer and method for forming the same) The photoelectric conversion layer 40 is a layer containing a metal halide perovskite organic compound (perovskite compound), and is a layer that generates electrons and holes upon irradiation with light. In this specification, the metal halide perovskite compound refers to a compound having a structure represented by the general formula ABX3. In the above general formula, A represents an organic group MA (methylammonium (CH3NH3 + )), an organic group FA (formamidinium (HC(NH2)2 + )), a cesium cation (Cs + ), a potassium cation (K + ), or a rubidium cation (Rb + ). Also, B in the general formula represents a metal ion Pb 2+ or Sn 2+ . Further, X in the general formula represents a halogen ion F - , Cl - , I - , or Br - .

[0026] The photoelectric conversion layer 40 may contain components other than the metal halide perovskite compound as long as the object and effect of the present embodiment are not impaired. However, the total mass of the perovskite compound in the photoelectric conversion layer 40 is preferably 60% by mass or more, and more preferably 90% by mass or more, based on the total mass of the photoelectric conversion layer 40.

[0027] The photoelectric conversion layer 40 can be formed by preparing a laminate in which a substrate 10, an anode layer 20, and a hole transport layer 30 are laminated in this order, and then performing the coating film forming step, the crystal precursor forming step, and the annealing step as described above.

[0028] · Coating film forming step In the coating film formation step, a coating film containing a metal halide perovskite compound and / or its raw materials, and a solvent, is formed on the hole transport layer 30. The method for forming the coating film is not particularly limited. For example, a perovskite solution containing a metal halide perovskite compound and / or its raw materials, and a solvent, may be prepared and applied to the hole transport layer 30 by a known method. Alternatively, a method may be used in which compounds such as CsBr, PBBr2, and PBI2 are deposited by co-deposition using vacuum deposition, and then a coating film is formed by applying a solvent such as formamidine hydroiodide (FAI) or formamidine hydrobromide (FABr) to the deposited film. Forming the coating film by applying a perovskite solution is preferable because it can be done simply. The following description will use the case of forming the coating film by this application method as an example.

[0029] When a coating film is formed by applying a perovskite solution, the application method is not particularly limited. Examples of application methods include spin coating, slit coating, die coating, spray coating, and roll coating.

[0030] The perovskite solution may be a metal halide perovskite compound dissolved in a solvent, or it may be a metal halide perovskite compound raw material dissolved in a solvent. Examples of raw materials for metal halide perovskite compounds include compounds represented by the general formula AX (where A and X are the same as those in the general formula AB mentioned above). m X n (Similar to A and X in the above-mentioned AB) and ions derived from the compound, compounds represented by the general formula BX2 (B and X are the same as the general formula AB in the above-mentioned AB m X n It contains ions derived from the compound (similar to B and X in the above). Compounds represented by the general formula AX can be used alone or in combination of two or more. Similarly, compounds represented by the general formula BX2 can be used alone or in combination of two or more.

[0031] Furthermore, the type of solvent contained in the coating film (perovskite solution) is not particularly limited, as long as it can dissolve the metal halide perovskite compound and its raw materials and has a vapor pressure that can be appropriately removed in the crystal precursor formation step described later. For example, a solvent having a vapor pressure of 1 Pa to 10,000 Pa at 35°C to 105°C is preferred, and a solvent having a vapor pressure of 10 Pa to 5,000 Pa is more preferred.

[0032] Examples of such solvents include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), triethyl phosphate (TEP), 4-formylmorpholine (NFN), dimethylacetamide (DMAC), 2-methoxyethanol, and 1,3-dimethyl-2-imidazolidinone (DMI). These can be used individually or in combination of two or more. Among these, a mixed solvent of DMSO and NMP is preferred because it readily dissolves metal halide perovskite compounds and their precursors, and has a low burden on the human body and the environment. When combining DMSO and NMP, the ratio is preferably 1:99 to 99:1, and more preferably 1:99 to 10:90 or 90:10 to 99:1.

[0033] The thickness of the coating formed in the coating film formation process is appropriately selected according to the desired thickness of the photoelectric conversion layer coating (such as the light absorption properties of the photoelectric conversion layer 40). It is preferable to adjust the final thickness of the photoelectric conversion layer 40 to be between 100 nm and 1 μm, and more preferably between 300 nm and 800 nm. When the thickness of the photoelectric conversion layer 40 is within this range, sunlight can be absorbed efficiently, and a higher electromotive force can be generated.

[0034] ·Crystal precursor layer formation process In the crystal precursor layer formation step, the coating film prepared in the above coating film formation step is held in an environment of 35°C to 105°C and 100 Pa or less, and the solvent is removed to form a crystal precursor layer.

[0035] In the crystal precursor layer formation process, when reducing the atmospheric pressure, it is preferable to reduce the pressure from atmospheric pressure to 100 Pa or less within 100 seconds, and more preferably within 30 seconds. By keeping the pressure reduction rate within this range, the structure of the crystal precursor formed in the crystal precursor layer formation process is more likely to be in a more desired state, and the performance of the final photoelectric conversion layer 40 is more likely to be improved.

[0036] In the crystal precursor layer formation process, the temperature at which the coating film is held is preferably 40°C to 100°C, and more preferably 40°C to 80°C. During the crystal precursor layer formation process, the temperature of the coating film may be kept constant or varied within the above temperature range. However, keeping the temperature constant is preferable from the viewpoint of ensuring that the evaporation rate of the solvent remains constant. In this embodiment, if it is difficult to directly measure the temperature of the coating film, the temperature of the stage on which the substrate 10 is placed during the crystal precursor layer formation process may be considered as the temperature of the coating film. In this embodiment, since the thickness of the coating film, hole transport layer 30, anode layer 20, substrate 10, etc., is sufficiently thin, there is no problem in considering the temperature of the stage as the temperature of the coating film.

[0037] Furthermore, in the crystal precursor layer formation process, the pressure of the environment holding the coating film should be 100 Pa or less, more preferably 20 Pa or less, and even more preferably 10 Pa or less. When the pressure of the environment holding the coating film is within this range, it is possible to efficiently remove the solvent.

[0038] The time for holding the above coating film in an environment of 35°C to 105°C and 20 Pa or less is not particularly limited as long as it is sufficient to remove the solvent, but it is preferably 1 minute to 30 minutes, and more preferably 5 minutes to 15 minutes. Holding time of 1 minute or more makes it easier to remove the solvent sufficiently. Also, holding time of 30 minutes or less tends to increase the efficiency of crystal precursor layer formation.

[0039] The apparatus used for the crystal precursor layer formation process is not particularly limited, but for example, the solar cell manufacturing apparatus described later can be used.

[0040] • Annealing process After the crystal precursor layer formation step described above, the crystal precursor layer, hole transport layer, substrate, etc. obtained above are annealed (heated) at atmospheric pressure at a temperature of 50°C to 180°C, more preferably 70°C to 150°C. The annealing may be carried out in air or in an inert atmosphere such as nitrogen or argon. The heating method is not particularly limited and can be carried out by known methods. For example, heating can be done using a hot plate or oven. In this embodiment, the annealing step may be performed after the crystal precursor layer etc. has been returned to room temperature, or the annealing step may be performed immediately after the crystal precursor layer formation step (without returning to room temperature). Furthermore, the temperature at which the crystal precursor layer formation step is performed and the temperature at which the annealing step is performed may be higher.

[0041] The annealing time is preferably between 1 minute and 60 minutes, and more preferably between 1 minute and 30 minutes. This annealing promotes the crystallization of the metal halide perovskite compound, resulting in the desired photoelectric conversion layer.

[0042] (substrate) The substrate 10 used in this embodiment only needs to be transparent to sunlight and have sufficient strength to support each component of the solar cell 100. Examples of materials constituting the substrate 10 include inorganic materials such as soda glass; and resin materials such as fluororesin and polyimide that have light transmission properties. In this specification, "transmissive to sunlight" means that the transmittance of light at any wavelength between 200 nm and 1500 nm is 10% or more.

[0043] (Anode layer and method for forming the same) The anode layer 20 is preferably a transparent conductive film that is conductive and transparent to sunlight. Examples of materials for such a transparent conductive film include metal oxides. Examples of metal oxides include metal oxides containing indium, zinc, or alloys thereof. Specifically, these include indium oxide such as indium oxide (In2O3 or In2O3:H), indium tin oxide (abbreviated as ITO), indium oxide containing fluorine (FTO), indium tin oxide containing silicon or silicon oxide (abbreviated as ITSO), and indium oxide containing tungsten oxide and zinc oxide (abbreviated as IWZO); zinc oxide such as zinc oxide (ZnO), zinc oxide containing gallium (abbreviated as GZO), and zinc oxide containing aluminum (abbreviated as AZO); and tin oxide (SnO2). These materials may be used individually or in combination of two or more.

[0044] The method for forming the anode layer 20, which is the transparent conductive film described above, is not particularly limited. For example, an ink in which nanoparticles of the metal oxide are dispersed in a dispersion medium may be prepared, and this may be applied to the substrate 10 by various coating methods, and the dispersion medium may be removed to form the anode layer 20. Alternatively, the metal oxide may be deposited on the substrate 10 by sputtering or vacuum deposition to form the anode layer 20.

[0045] The thickness of the anodic layer 20 (transparent conductive film) to be formed is not particularly limited as long as it can exhibit sufficient conductivity, but it is desirable to adjust it so that the sheet resistance value is between 5Ω / □ and 100Ω / □.

[0046] (Hole transport layer and method for forming the same) The hole transport layer 30 is a layer that transfers holes generated in the photoelectric conversion layer 40 to the anode layer 20, and suppresses the movement of electrons generated in the photoelectric conversion layer 40 to the anode layer 20. The hole transport layer 30 may be a single layer, or it may be composed of multiple layers of the same or different types.

[0047] Examples of hole transport materials include [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (abbreviated as MeO-4PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as 2PACz), and [2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid Self-assembled monolayer materials containing phosphonic acids such as nickel oxide (Br-2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz); nickel oxide (NiO x ), tungsten oxide (WO x This includes metal oxides such as aluminum oxide (AlO); and organic semiconductors such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (abbreviated as PTAA), poly[(9,9-dictylfluorenyl-2,7-diyl)-co-(4,4'(N-(4-sec-butylphenyl)diphenylamine)) (abbreviated as TFB), and poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (abbreviated as PEDOT:PSS). These hole transport materials may be used individually or in combination of two or more.

[0048] The method for forming the hole transport layer 30 is not particularly limited. For example, the hole transport layer 30 may be formed by dissolving or dispersing a hole transport material in a liquid, coating it onto the anode layer 20 using a known coating method (e.g., spin coating), and then removing the liquid. Alternatively, the hole transport layer 30 may be formed by depositing the hole transport material onto the anode layer 20 using a vacuum thermal deposition method or the like.

[0049] The thickness of the hole transport layer 30 to be formed is not particularly limited as long as it can exhibit the above-mentioned hole transport performance, but is preferably 1 μm or less, and more preferably 100 nm or less.

[0050] (Electron transport layer and method for forming the same) The electron transport layer 50 may be composed of a single layer, but in this embodiment, the electron transport layer 50 is composed of two layers: a first electron transport layer 51 and a second electron transport layer 52.

[0051] The first electron transport layer 51 is a layer located adjacent to the photoelectric conversion layer 40 on the side of the photoelectric conversion layer 40 opposite to the hole transport layer 30. The first electron transport layer 51 is C 60 Fullerene or phenyl C 61 C such as methyl butyrate (PCBM) 60 This includes fullerene derivatives, etc. Furthermore, the first electron transport layer 51 may also be a layer containing a perylenediimide derivative. Specific examples of perylenediimide derivatives include N,N'-bis(2-ethylhexyl)-3,4,9,10-perylenetetracarboxylic acid diimide, N,N'-bis(n-octyl)-3,4,9,10-perylenetetracarboxylic acid diimide (abbreviation: PTCDI-C8), N,N'-bis(4-methoxyphenyl)-3,4,9,10-perylenetetracarboxylic acid diimide, N,N'-bis(3,5-dimethylphenyl)-3,4,9,10-perylenetetracarboxylic acid diimide, and N,N'-bis(1-naphthyl)-3,4,9,10-perylenetetracarboxylic acid diimide.

[0052] The thickness of the first electron transport layer 51 is not particularly limited, but is preferably 1 nm to 100 nm, and more preferably 1 nm to 50 nm. By arranging the first electron transport layer 51 adjacent to the photoelectric conversion layer 40, electrons generated in the photoelectric conversion layer 40 can be efficiently extracted.

[0053] The method for forming the first electron transport layer 51 is not particularly limited, and it can be formed on the photoelectric conversion layer 40 by depositing the material by vacuum thermal deposition or by coating by a coating method.

[0054] The second electron transport layer 52 is a layer positioned between the first electron transport layer 51 and the cathode layer 60, and its main purpose is to move electrons generated in the photoelectric conversion layer 40 towards the cathode layer 60 and to block holes from moving towards the cathode layer 60. The second electron transport layer 52 only needs to contain a hole-blocking compound, and may further contain components other than hole-blocking compounds as long as the purpose and effects of this embodiment are not impaired.

[0055] Examples of hole-blocking compounds include 1,10-phenanthroline derivatives such as 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (β-NBPhen), phenylpyridine derivatives, organometallic complexes having lithium or aluminum and an 8-quinolinol ligand, and conductive metal oxides containing tin. Examples of conductive metal oxides containing tin include tin oxide (SnO2), fluorine-doped tin oxide (FTO), and tungsten-doped tin oxide.

[0056] The thickness of the second electron transport layer 52 containing the hole-blocking compound is preferably 1 nm to 100 nm, and more preferably 1 nm to 50 nm. When the thickness of the second electron transport layer 52 is within this range, the hole-blocking properties of the second electron transport layer 52 are further improved, and the photoelectric conversion characteristics of the solar cell 100 tend to be further improved.

[0057] The method for forming the second electron transport layer 52 is appropriately selected depending on the type of hole-blocking compound, and examples include vacuum deposition, solution coating, atomic layer deposition (ALD), and sputtering.

[0058] (Cathode layer and method for forming the same) The cathode layer 60 is not particularly limited in structure or type, as long as it is possible to extract current to the outside. The cathode layer 60 may consist of a single layer, or it may consist of two layers: a conductive film 61 made of a metallic conductive film or a light-transmitting film disposed over its entire surface so as to cover the electron transport layer 50 described above, and auxiliary electrodes 62 arranged in a pattern on the conductive film.

[0059] The single-layer cathode layer 60 can be made of, for example, platinum, gold, silver, copper, aluminum, magnesium, rhodium, indium, titanium, iron, nickel, tin, zinc, palladium, or an alloy thereof. The method for forming such a cathode layer 60 is not particularly limited, and the above metals or alloys can be deposited using known methods.

[0060] On the other hand, if light transmittance is required for the cathode layer 60, it is necessary to use a conductive film with light transmittance for the cathode layer 60. However, in this case, the series resistance may increase when the solar cell 100 is made larger in area. Therefore, when light transmittance is required for the cathode layer 60, it is preferable to combine a conductive film 61 with light transmittance and an auxiliary electrode 62 with high conductivity.

[0061] The material constituting the conductive film 61 can be the same as the material used for the anode layer 20 described above. The method for forming the conductive film 61 can also be the same as the method for forming the anode layer 20 described above. In this case, the thickness of the conductive film 61 is not particularly limited as long as it can exhibit sufficient conductivity, but is preferably 10 nm to 1 μm, and more preferably 50 nm to 600 nm. Furthermore, it is desirable to adjust the sheet resistance of the conductive film 61 to be between 5 Ω / □ and 100 Ω / □.

[0062] On the other hand, the auxiliary electrode 62 can be formed by forming a pattern of platinum, gold, silver, copper, aluminum, magnesium, rhodium, indium, titanium, iron, nickel, tin, zinc, palladium, or alloys thereof using known methods. The pattern and thickness of the auxiliary electrode 62 are appropriately selected depending on the application of the solar cell and the light-receiving area, but are preferably 1 μm to 500 μm, and more preferably 5 μm to 30 μm.

[0063] Furthermore, after the formation of the cathode layer 60 (the conductive film 61 and auxiliary electrode 62), heat treatment may be performed in air or in argon or nitrogen at a temperature ranging from 50°C to 200°C, if necessary.

[0064] (modified version) The above describes a solar cell 100 having a substrate 10, an anode layer 20, a hole transport layer 30, a photoelectric conversion layer 40, an electron transport layer 50, and a cathode layer 60 in that order, as well as a method for forming each layer. However, the structure and manufacturing method of the solar cell of the present invention are not limited thereto. The solar cell 100 may further include any other necessary layers, and may further include a step for forming such layers as appropriate.

[0065] Furthermore, solar cells having a substrate on the cathode layer 60 side, where sunlight is incident from the cathode layer side, can also be manufactured using the same method. In this case, the desired solar cell can be obtained by stacking the cathode layer, electron transport layer, photoelectric conversion layer, hole transport layer, and anode layer on the substrate in this order.

[0066] Furthermore, the above-described method for manufacturing solar cells can also be applied when manufacturing tandem-type solar cells, and the method for manufacturing solar cells may further include layer formation steps other than those described above.

[0067] 2. Solar cell manufacturing equipment A solar cell manufacturing apparatus that can be used in the solar cell manufacturing method described above will be explained. This manufacturing apparatus is mainly used for forming the photoelectric conversion layer described above, and can be used in particular in the crystal precursor layer formation process. A schematic diagram of the manufacturing apparatus is shown in Figure 2. The manufacturing apparatus 500 has a vacuum chamber 200, a vacuum mechanism 300 connected to the vacuum chamber 200 for reducing the pressure inside the vacuum chamber, and a temperature control mechanism 400 for adjusting the stage temperature inside the vacuum chamber 200.

[0068] The vacuum chamber 200 comprises a housing 210 and a stage 220 for placing a sample (a laminate including the perovskite solution coating mentioned above) 110. The housing 210 consists of a main body 211 having a housing section for housing the stage 220 and the sample 110, and a top cover 212 positioned to cover the housing section. One end of the top cover 212 is pivotally supported on the main body 211. An observation window 212a for observing the sample 110 housed inside the housing 210 is provided on a part of the top cover 212. On the other hand, an opening 211a for connecting to the vacuum mechanism 300 is provided at the bottom of the main body 211.

[0069] The stage 220, located within the housing 210, is connected to a temperature control mechanism 400 and is configured to be adjustable to a desired temperature. In Figure 2, the stage 220 is configured to hold only one sample 110. However, the stage 220 may be configured to hold multiple samples 110. Also, in Figure 2, only one stage 220 is located inside the housing 210, but multiple stages 220 may be located inside the housing.

[0070] On the other hand, the depressurization mechanism 300 is connected to the opening 211a of the depressurization chamber 200 and is configured to reduce the pressure inside the depressurization chamber 200 to a desired pressure. The depressurization mechanism 300 may be equipped with, for example, an oil-free vacuum pump such as a dry pump (not shown), a vacuum gauge (not shown), an on / off valve (not shown), a pressure adjustment valve for adjusting the pressure inside the depressurization chamber, and can have the same configuration as known depressurization mechanisms. It is preferable, from the viewpoint of worker safety and environmental considerations, that the depressurization mechanism 300 has a recovery means (not shown) for recovering the solvent from the gas drawn in from the depressurization chamber 200.

[0071] Furthermore, the temperature control mechanism 400 is connected to the stage 220 in the reduced pressure chamber 200 and only needs to have a configuration for adjusting the temperature of the stage 220 (sample 110) to a desired temperature. The temperature control mechanism 400 may, for example, be equipped with heating means (not shown), cooling means (not shown), temperature measuring means (not shown), etc., and can have a configuration similar to known temperature control mechanisms.

[0072] When using the manufacturing apparatus 500, the top cover 212 of the vacuum chamber 200 is opened, and the sample 110 (a laminate of a substrate, anode layer, hole transport layer, and perovskite solution coating) is placed on the stage 220, which has been heated to a desired temperature by the temperature control mechanism 400. Then, the top cover 212 is closed to seal the vacuum chamber 200. The vacuum mechanism 300 exhausts the air from the vacuum chamber 200, reduces the pressure inside the vacuum chamber 200, and maintains this pressure for a certain period of time. After the period of time has elapsed, the heating and vacuum are released, and the pressure is returned to atmospheric pressure. As a result, the solvent is removed from the coating of the sample 110, and the crystal precursor layer described above is formed.

[0073] (modified version) The above describes the formation of a crystal precursor layer using the manufacturing apparatus 500 described above. However, after the formation of the crystal precursor layer, the temperature of the stage 220 may be adjusted by the temperature control means 400, and the crystal precursor layer may be further annealed (the annealing process described above) on the stage 220.

[0074] Furthermore, the apparatus may further include means for applying a perovskite solution, etc. In this case, it becomes possible to apply the perovskite solution (the coating film formation step described above) on the stage 220. [Examples]

[0075] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited in any way thereto.

[0076] <Preparing the materials> The following materials and compositions were prepared to form solar cells. All materials were stored in a dry nitrogen environment until immediately before use. • Hole transport layer formation solution: 1 mM ethanol solution of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz) (manufactured by Tokyo Chemical Industry Co., Ltd.) (manufactured by Fujifilm Wako Co., Ltd.) • Solution for forming the photoelectric conversion layer: Perovskite solution prepared by the method described below. ·C 60 Fullerene (manufactured by Sigma-Aldrich) • Hole-blocking compound: BCP (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0077] (Method for preparing perovskite solution) Preparation of perovskite solution A using a mixed solution of NMP and DMSO as the solvent. Formamidine hydroiodide (FAI), lead(II) iodide (PbI2), methylammonium bromide (MABr), and lead bromide (PbBr2) (all manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in N-methyl-2-pyrrolidone (NMP) (manufactured by Fujifilm Wako Co., Ltd.). Furthermore, cesium iodide (CsI) (manufactured by Sigma-Aldrich) was dissolved in dimethyl sulfoxide (DMSO) (manufactured by Fujifilm Wako Co., Ltd.). And then, a metal halide perovskite compound (Cs) at a concentration of 1.2 M 0.05 (Fa 0.76 MA 0.24 ) 0.95 Pb(I 0.76 / Br 0.24 A solution containing )3) (where FA represents formamidine and MA represents methylammonium in the chemical formula) was prepared.

[0078] Preparation of perovskite solution B using a mixed solution of DMF and DMSO as the solvent. Formamidine hydroiodide (FAI), lead(II) iodide (PbI2), methylammonium bromide (MABr), and lead bromide (PbBr2) (all manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) (manufactured by Fujifilm Wako Co., Ltd.) and dimethyl sulfoxide (DMSO) (manufactured by Fujifilm Wako Co., Ltd.) in a volume ratio of 4:1. Furthermore, cesium iodide (CsI) (manufactured by Sigma-Aldrich) was dissolved in dimethyl sulfoxide (DMSO) (manufactured by Fujifilm Wako Co., Ltd.). And then, a metal halide perovskite compound (Cs) at a concentration of 1.2 M 0.05 (Fa 0.76 MA 0.24 ) 0.95 Pb(I 0.76 / Br 0.24 A solution containing )3) (where FA represents formamidine and MA represents methylammonium in the chemical formula) was prepared.

[0079] 1. Experimental Examples To confirm the relationship between the temperature of the crystal precursor layer formation process and the absorbance of the resulting photoelectric conversion layer, samples (photoelectric conversion layers) were prepared at different temperatures during the crystal precursor layer formation process, and their absorbance was measured.

[0080] (1) Sample preparation A glass substrate (20 x 25 mm square) with a transparent conductive film made of indium tin oxide (ITO) was prepared. The transparent conductive film-coated glass substrate was sequentially immersed in a surfactant aqueous solution, water, acetone, and 2-propanol, and ultrasonically cleaned for 30 minutes in each solution. After cleaning, it was dried at 60°C for 16 hours, and then the surface was modified in an ultraviolet-ozone surface modification device for 30 minutes. It was then immediately transported to a dry nitrogen environment.

[0081] A hole transport layer formation solution (MeO-4PACz) capable of forming a self-assembled monolayer was applied to the transparent conductive film of the glass substrate with the transparent conductive film using a spin coater. Then, heat treatment was performed at 100°C for 10 minutes to obtain a hole transport layer.

[0082] A perovskite solution A, using a mixed solution of NMP and DMSO as the solvent, was applied to the hole transport layer using a spin coater. The laminate was then placed on a stage 220 of the manufacturing apparatus 500 shown in Figure 2, which was adjusted to 40°C. The vacuum chamber 200 was then sealed, and the air inside the vacuum chamber 200 was removed by the vacuum mechanism 300. The pressure inside the vacuum chamber 200 reached below 10 Pa from atmospheric pressure in approximately 5 seconds. The laminate was then held in an environment of 10 Pa or less and 40°C (stage temperature) for 10 minutes to form a crystalline precursor layer.

[0083] Subsequently, the pressure inside the vacuum chamber 200 was returned to atmospheric pressure, and the laminate was removed from the vacuum chamber 200. The laminate was then heat-treated in air on a hot plate at 150°C for 2 minutes. This caused the crystal precursor layer to crystallize, and a photoelectric conversion layer was obtained. Through these steps, a sample having a transparent conductive film-coated glass substrate, a hole transport layer, and a photoelectric conversion layer was obtained.

[0084] • Methods for manufacturing solar cells 2-6 Samples were prepared in the same manner as described above, except that the temperature during crystal precursor preparation (temperature of stage 220 in vacuum chamber 200) was set to 25°C (no heating), 50°C, 70°C, 100°C, or 110°C.

[0085] (2) Evaluation The absorbance of the six samples described above was measured using a spectrophotometer (Hitachi spectrophotometer), and each was compared. Figure 3 shows the wavelength dependence of the absorbance of each sample.

[0086] Metal halide perovskite compounds (Cs 0.05 (Fa 0.76 MA 0.24 ) 0.95 Pb(I 0.76 / Br 0.24 The band gap of (3) is approximately 1.69 eV. Therefore, the absorption wavelength of the film (photoelectric conversion layer) corresponding to this band gap is approximately 730 nm. In the graph in Figure 3, a good result can be said to be one in which the absorbance rises sharply around the wavelength of 730 nm, and high absorbance is also present at wavelengths below 600 nm.

[0087] As shown in Figure 3, when heated at 110°C, the absorbance rises at wavelengths longer than 730 nm. Therefore, a shift in the band gap occurs, indicating that the desired state is not achieved. On the other hand, in the unheated sample (25°C), although the absorbance rises around 730 nm, the absorbance decreases below 600 nm. Therefore, the crystallinity of the metal halide perovskite compound is reduced.

[0088] On the other hand, when heated between 40°C and 100°C, the absorbance not only rises sharply around a wavelength of 730 nm, but also exhibits excellent absorbance in the region below 600 nm. Therefore, it can be said that excellent perovskite crystals were obtained in these temperature ranges. Thus, it was demonstrated that the preferred temperature for performing the vacuum quench method when forming the crystal precursor layer is between 35°C and 105°C (40°C and 100°C).

[0089] <Fabrication of solar cells> [Comparative Example 1] A 1.04 cm² area on a glass substrate (size 20 x 25 mm square). 2The solar cells were fabricated using the vacuum quenching method (without substrate heating). Specifically, they were fabricated using the following method.

[0090] Preparation of substrate with anode (transparent conductive film) A glass substrate (20 x 25 mm square) with a transparent conductive film made of indium tin oxide (ITO) was prepared. The transparent conductive film-coated glass substrate was sequentially immersed in a surfactant aqueous solution, water, acetone, and 2-propanol, and ultrasonically cleaned for 30 minutes in each solution. After cleaning, it was dried at 60°C for 16 hours, and then the surface was modified in an ultraviolet-ozone surface modification device for 30 minutes. It was then immediately transported to a dry nitrogen environment.

[0091] • Formation of hole transport layer A hole transport layer formation solution (MeO-4PACz) capable of forming a self-assembled monolayer was applied to the transparent conductive film of the glass substrate with the transparent conductive film using a spin coater. Then, heat treatment was performed at 100°C for 10 minutes to obtain a hole transport layer.

[0092] • Formation of the photoconversion layer A perovskite solution A, using a mixed solution of NMP and DMSO as solvents, was applied to the hole transport layer using a spin coater. The laminate was then placed on the stage 220 of the manufacturing apparatus 500 shown in Figure 2. The stage 220 was not heated at this time. The vacuum chamber 200 was then sealed, and the air inside the vacuum chamber 200 was removed by the vacuum mechanism 300. The pressure inside the vacuum chamber 200 reached below 5 Pa from atmospheric pressure in approximately 5 seconds. The laminate was then held in this environment for 10 minutes to form a crystal precursor layer. Afterward, the pressure inside the vacuum chamber 200 was returned to atmospheric pressure, and the laminate was removed from the vacuum chamber 200. The laminate was then heat-treated in air on a hot plate at 150°C for 2 minutes to complete crystallization. This yielded a photoelectric conversion layer (perovskite layer).

[0093] • Formation of the electron transport layer On the above photoelectric conversion layer, C 60A first electron transport layer was formed by vacuum deposition of 30 nm. Subsequently, a second electron transport layer was formed on the first electron transport layer by vacuum deposition of BCP at an 8 nm depth.

[0094] • Formation of the cathode layer A solar cell was obtained by vacuum-depositing silver onto the electron transport layer described above to form a cathode layer.

[0095] [Example 1] A solar cell was fabricated in the same manner as in Comparative Example 1, except that the method for fabricating the photoelectric conversion layer was modified as follows.

[0096] • Formation of the photoconversion layer A perovskite solution A, using a mixed solution of NMP and DMSO as solvents, was applied to the hole transport layer using a spin coater. The laminate was then placed on the stage 220 of the manufacturing apparatus 500 shown in Figure 2. The temperature of the stage 220 was set to 50°C. The vacuum chamber 200 was then sealed, and the air inside was removed by the vacuum mechanism 300. The pressure inside the vacuum chamber 200 reached below 5 Pa from atmospheric pressure in approximately 5 seconds. The laminate was then held in this environment for 10 minutes to form a crystal precursor layer. Afterward, the pressure inside the vacuum chamber 200 was returned to atmospheric pressure and room temperature, and the laminate was removed from the vacuum chamber 200. The laminate was then heat-treated in air on a hot plate at 150°C for 2 minutes to complete crystallization. This yielded a photoelectric conversion layer (perovskite layer).

[0097] [Reference example 1] A solar cell was fabricated in the same manner as in Comparative Example 1, except that the photoelectric conversion layer was prepared using the following poor solvent method.

[0098] • Formation of the photoconversion layer Perovskite solution B, using a mixed solution of DMF and DMSO as the solvent, was added dropwise onto the hole transport layer described above, and anisole was added dropwise as a poor solvent at an appropriate time. This initiated crystallization of the perovskite compound in the perovskite solution. Subsequently, a photoelectric conversion layer (perovskite layer) was obtained by heat treatment at 100°C for 10 minutes.

[0099] [evaluation] Current probes and voltage probes for measurement were brought into contact with the solar cells prepared in Example 1, Comparative Example 1, and Reference Example 1, respectively, and simulated sunlight was irradiated from the glass substrate side to generate electricity. The current and voltage characteristics at this time were measured using the four-terminal method. The measurement results are shown in Table 1 below. In this specification, the sweep direction of a positive voltage is referred to as the forward sweep, and the sweep direction of a negative voltage is referred to as the reverse sweep.

[0100] [result] [Table 1]

[0101] As shown in Table 1 above, in the crystal precursor layer formation process (vacuum quenching), the solar cell of Example 1, in which the sample was heated to 50°C, showed improved conversion efficiency compared to the solar cell of Comparative Example 1, in which the sample was not heated. In particular, the forward sweep conversion efficiency was approximately 17%, which was close to the value of the solar cell manufactured by the poor solvent method using DMF (Reference Example 1). Furthermore, although the short-circuit current density of the solar cell of Example 1 was slightly lower than that of the solar cell of Reference Example 1, the open-circuit voltage showed a comparable value. In other words, the solar cell manufacturing method of the present invention allows for the production of solar cells with excellent characteristics without the use of large-scale manufacturing equipment. Moreover, this method does not require the use of DMF as a solvent.

[0102] [Comparative Example 2] A glass substrate (substrate size 100 mm square) having a transparent conductive film with a pattern formed from an indium tin oxide (ITO) film was prepared. After coating the glass substrate with a hole transport layer and a photoelectric conversion layer (perovskite layer), a battery transport layer and a patterned cathode layer were formed by vacuum deposition, thereby creating multiple solar cells (area 0.09 cm²) on a single glass substrate. 2 A crystal precursor layer was formed. The method for forming each layer was the same as in Comparative Example 1. The pressure inside the vacuum chamber 200 during crystal precursor layer preparation reached approximately 10 Pa or less 5 seconds after vacuum evacuation. The vacuum chamber was maintained at 25°C and pressure for 10 minutes.

[0103] [Example 2] A glass substrate (substrate size 100 mm square) having a transparent conductive film with a pattern formed from an indium tin oxide (ITO) film was prepared. After coating the glass substrate with a hole transport layer and a photoelectric conversion layer (perovskite layer), a battery transport layer and a patterned cathode layer were formed by vacuum deposition, thereby creating multiple solar cells (area 0.09 cm²) on a single glass substrate. 2 A crystal precursor layer was formed. The method for forming each layer was the same as in Example 1. The pressure inside the vacuum chamber 200 during crystal precursor layer preparation reached approximately 10 Pa or less 5 seconds after vacuum evacuation. The vacuum chamber was also maintained at 50°C and pressure for 10 minutes.

[0104] [evaluation] For each example and comparative example, a current probe and a voltage probe were brought into contact with the solar cells, respectively, and simulated sunlight was irradiated from the glass substrate side. The current and voltage characteristics during power generation were measured using the four-terminal method. Three cells arranged on a 10 cm square substrate were evaluated. The measurement results are shown in Table 2 below. In this specification, the sweep direction of a positive voltage is referred to as the forward sweep, and the sweep direction of a negative voltage is referred to as the reverse sweep.

[0105] [result] [Table 2]

[0106] As shown in Table 2 above, the cell of Example 2, in which the temperature during crystal precursor layer formation was 50°C, showed improved conversion efficiency for all samples compared to the cell of Comparative Example 2, in which the sample was not heated. Furthermore, the conversion efficiency of Example 2 during forward sweeping was approximately 17%. From these results, it can be seen that the solar cell manufacturing method of the present invention yields a solar cell with good characteristics even when using a relatively large substrate, and also exhibits excellent uniformity within the plane. [Industrial applicability]

[0107] According to the present invention, perovskite-type solar cells with good performance can be manufactured using various solvents without the need for large-scale equipment. [Explanation of Symbols]

[0108] 10 circuit boards 20 Anode layer 30 Hole transport layer 40 Photoelectric conversion layer 50 Electron transport layer 51 First electron transport layer 52 Second electron transport layer 60 Cathode layer 61 Conductive film 62 Auxiliary electrode 200 Reduced Pressure Chamber 210 cabinets 211 Main Unit 211a opening 212 Top lid 212a Observation window 220 stages 300 Pressure reduction mechanism 400 Temperature adjustment mechanism 500 Manufacturing equipment

Claims

1. A photoelectric conversion layer containing a metal halide perovskite compound, An electron transport layer disposed on one side of the photoelectric conversion layer, A hole transport layer disposed on the other side of the photoelectric conversion layer, A method for manufacturing a solar cell having at least the following: A step of forming a coating film on the hole transport layer or the electron transport layer containing the metal halide perovskite compound and / or its raw material, and a solvent, The process involves maintaining the coating film in an environment of 35°C to 105°C and 100 Pa or less, removing the solvent, and forming a crystalline precursor layer. A method for manufacturing solar cells, including [the specified part of the method].

2. In the step of forming the crystal precursor layer, the environment holding the coating film is reduced in pressure from atmospheric pressure to 100 Pa or less within 100 seconds. A method for manufacturing a solar cell according to claim 1.

3. In the step of forming the crystalline precursor layer, the coating film is held for 1 minute to 30 minutes in an environment of 35°C to 105°C and 100 Pa or less. A method for manufacturing a solar cell according to claim 1.

4. The process further includes annealing the crystalline precursor layer under atmospheric pressure and at a temperature of 50°C to 180°C to form a photoelectric conversion layer. A method for manufacturing a solar cell according to claim 1.

5. A decompression chamber and A depressurization mechanism connected to the depressurization chamber for reducing the pressure inside the depressurization chamber, A temperature control mechanism for adjusting the stage temperature in the aforementioned depressurized chamber, This is a solar cell manufacturing apparatus that includes, In the vacuum chamber, the solvent is removed from the coating film containing the metal halide perovskite compound and / or its raw materials, Solar cell manufacturing equipment.

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