Perovskite solar cell and method for manufacturing the same

Abstract

The present invention aims to provide a solar cell having a photoelectric conversion layer with a passivation layer formed on its surface, and a method for manufacturing the same. [Solution] The present invention relates to a method for manufacturing a solar cell having a photoelectric conversion layer containing a perovskite compound, comprising the steps of: applying a precursor solution containing the perovskite compound as a solute to a coating surface on a substrate to form the photoelectric conversion layer; and forming a passivation layer on the surface of the photoelectric conversion layer, wherein the step of forming the passivation layer comprises the steps of applying a solution containing 1 mM to 9 mM of trishydroxymethylaminomethane to the surface of the photoelectric conversion layer; and drying the applied solution, and the solar cell obtained by this manufacturing method.

Description

[Technical Field]

[0001] This invention relates to a perovskite solar cell and a method for manufacturing the same. [Background technology]

[0002] One type of solar cell known is the perovskite solar cell, in which the main component of the photoelectric conversion layer is a perovskite compound. Patent Document 1 discloses a photoelectric conversion element having a protective layer (sometimes called a passivation layer) formed on the surface of a layer containing a perovskite compound using a predetermined surface treatment agent, a solar cell using the photoelectric conversion element, and methods for manufacturing them. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2018 / 043385 [Overview of the project] [Problems that the invention aims to solve]

[0004] Patent Document 1 describes a specific compound as a surface treatment agent used for surface treatment of a layer containing a perovskite compound. However, from the viewpoint of improving the performance of solar cells, there was room to consider other compounds as well. Therefore, the present invention aims to provide a solar cell having a photoelectric conversion layer on which a passivation layer is formed on the surface, and a method for manufacturing the same. [Means for solving the problem]

[0005] The inventors of the present invention have discovered that the power generation performance of a solar cell can be improved by forming a passivation layer using a trishydroxymethylaminomethane solution of a predetermined concentration, and have completed the present invention.

[0006] In other words, the gist of this invention is as follows: (1) A method for manufacturing a solar cell having a photoelectric conversion layer containing a perovskite compound, comprising: applying a precursor solution containing the perovskite compound as a solute onto a coating surface on a substrate to form the photoelectric conversion layer; forming a passivation layer on the surface of the photoelectric conversion layer; and the step of forming the passivation layer includes: applying a solution containing 1 mM or more and 9 mM or less of tris(hydroxymethyl)aminomethane onto the surface of the photoelectric conversion layer; drying the applied solution. A method for manufacturing a solar cell. (2) The perovskite compound is represented by the following formula (1): AMX3 (1) (wherein: A is at least one selected from cesium ion, methylammonium ion and formamidinium ion; M is at least one selected from divalent lead ion and tin ion; X is at least one selected from halogen ions). The method for manufacturing a solar cell according to (1) above. (3) A solar cell having a hole transport layer, a photoelectric conversion layer containing a perovskite compound, and an electron transport layer, wherein the photoelectric conversion layer is disposed between the hole transport layer and the electron transport layer; the photoelectric conversion layer has a passivation layer on its surface; the passivation layer is formed using a solution containing 1 mM or more and 9 mM or less of tris(hydroxymethyl)aminomethane. A solar cell. (4) The solar cell according to (3) above, wherein the photoelectric conversion layer has a passivation layer on the surface on the side of the electron transport layer.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a solar cell having a photoelectric conversion layer with a passivation layer formed on the surface and a method for manufacturing the same.

Brief Description of the Drawings

[0008] [Figure 1] It is a schematic cross-sectional view showing an example of the structure of the solar cell of the present invention. [Figure 2] It is a schematic cross-sectional view of the photoelectric conversion layer in the solar cell of the present invention. [Figure 3] It is a graph showing the relationship between the tris concentration and the power generation efficiency.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0010] <Configuration of Solar Cell> First, the structure of the perovskite solar cell (hereinafter, also referred to as the solar cell of the present invention) of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of the structure of the solar cell of the present invention. As shown in FIG. 1, in one embodiment, the solar cell C of the present invention includes a substrate 1, a first electrode layer 2a, a first carrier transport layer 3a, a photoelectric conversion layer 4, a second carrier transport layer 3b, and a second electrode layer 2b. These layers may be composed of one layer or may be composed of two or more layers.

[0011] (Photoelectric Conversion Layer 4) The photoelectric conversion layer 4 is a layer located between the first carrier transport layer 3a and the second carrier transport layer 3b. The photoelectric conversion layer 4 generates charge carriers by receiving light. The charge carriers generated in the photoelectric conversion layer 4 move to either the first carrier transport layer 3a or the second carrier transport layer 3b.

[0012] More specifically, positive charge carriers, i.e., holes, generated in the photoelectric conversion layer 4 are transported to the first electrode layer 2a or the second electrode layer 2b via the hole transport layer of the first carrier transport layer 3a and the second carrier transport layer 3b. Similarly, negative charge carriers, i.e., electrons, generated in the photoelectric conversion layer 4 are transported to the first electrode layer 2a or the second electrode layer 2b via the electron transport layer of the first carrier transport layer 3a and the second carrier transport layer 3b.

[0013] The photoelectric conversion layer 4 mainly contains a perovskite compound. The content of the perovskite compound in the photoelectric conversion layer 4 is usually 60% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, particularly preferably 95% by weight or more, and most preferably 100% by weight.

[0014] The thickness of the photoelectric conversion layer is typically between 100 nm and 1000 nm.

[0015] Perovskite compounds are compounds that have a perovskite-type crystal structure. The presence of a perovskite-type crystal structure in a compound can be confirmed, for example, by X-ray diffraction measurements.

[0016] The perovskite compound used in the present invention can be represented by the following formula (1). AMX3(1) (In the formula, A is a monovalent cation, M is a divalent cation, and X is a monovalent anion.)

[0017] In one embodiment, the perovskite compound used in the present invention is represented by the following formula (1). AMX3(1) (In the formula, A is cesium ion (Cs + ), methylammonium ion (CH3NH3 + :MA) and formamidinium ion (HC(NH2)2 + Includes at least one selected from :FA) M contains at least one selected from divalent lead ions (Pb 2+ ) and tin ions (Sn 2+ ), and X contains at least one selected from halogen ions. )

[0018] In formula (1), A may further contain other monovalent cations other than Cs + , MA and FA. Examples of other monovalent cations include monovalent organic ammonium ions, monovalent amidinium-based ions, and monovalent metal ions. Examples of monovalent organic ammonium ions include C2H5NH3 + , C3H7NH3 + and C4H9NH3 + . Examples of monovalent metal ions include rubidium ions (Rb + ).

[0019] In one embodiment, in formula (1), A is one or more selected from Cs + , MA and FA, preferably one or more selected from Cs + , MA and FA, more preferably two or more including Cs + and FA, and even more preferably consisting of these two.

[0020] In one embodiment, in formula (1), M is at least one selected from Pb 2+ and Sn 2+ , and from the perspective of durability, it is Pb 2+ .

[0021] In one embodiment, in formula (1), X is at least one selected from fluoride ions (F - ), chloride ions (Cl - ), bromide ions (Br - ) and iodide ions (I - ), and Cl - , Br - and I - are preferred, and Br - and I - are more preferred.

[0022] The solar cell C of the present invention has a passivation layer on the surface of the photoelectric conversion layer 4 opposite to the substrate (the surface on the side of the second carrier transport layer 3b in Figure 1). Figure 2 is a schematic cross-sectional view of the photoelectric conversion layer in the solar cell of the present invention. As shown in Figure 2, the photoelectric conversion layer 4 has a passivation layer 4b formed on the surface of a layer (perovskite layer) 4a mainly containing a perovskite compound. In this specification, this structure is also referred to as a photoelectric conversion layer 4 having a passivation layer on its surface. The passivation layer has the function of suppressing the adverse effects of crystal defects in the perovskite compound on the power generation performance. As will be described later, in the present invention, the power generation performance of the solar cell is improved by forming the passivation layer using a trishydroxymethylaminomethane solution of a predetermined concentration.

[0023] The passivation layer contains trishydroxymethylaminomethane. Trishydroxymethylaminomethane is a compound having the structure shown below and is also called trometamol or tris. Trishydroxymethylaminomethane is commercially available, for example, as Trisma base.

[0024] [ka]

[0025] The passivation layer is formed using a solution containing trishydroxymethylaminomethane at a concentration of 1 mM to 9 mM. Solar cells having a passivation layer formed using a trishydroxymethylaminomethane solution within this concentration range have high power generation performance.

[0026] The thickness of the passivation layer is typically greater than or equal to the thickness of the monolayer but less than or equal to 10 nm.

[0027] (First carrier transport layer 3a and second carrier transport layer 3b) The first carrier transport layer 3a receives charge carriers generated in the photoelectric conversion layer 4 and transports these charge carriers to the first electrode layer 2a. If the first carrier transport layer 3a is a hole transport layer (HTL), it transports holes to the first electrode layer 2a. If the first carrier transport layer 3a is an electron transport layer (ETL), it transports electrons to the first electrode layer 2a.

[0028] The second carrier transport layer 3b accepts charge carriers generated in the photoelectric conversion layer 4 and transports these charge carriers to the second electrode layer 2b. If the second carrier transport layer 3b is a hole transport layer, it transports holes to the second electrode layer 2b. If the second carrier transport layer 3b is an electron transport layer, it transports electrons to the second electrode layer 2b.

[0029] In one embodiment, the solar cell of the present invention has a hole transport layer, a photoelectric conversion layer, and an electron transport layer, the photoelectric conversion layer being disposed between the hole transport layer and the electron transport layer. These layers may be directly stacked, or other layers may be present between them.

[0030] In a first embodiment of the solar cell of the present invention, the first carrier transport layer 3a is an electron transport layer, and the second carrier transport layer 3b is a hole transport layer. In this embodiment, the photoelectric conversion layer has a passivation layer on the surface facing the hole transport layer.

[0031] In a second embodiment of the solar cell of the present invention, the first carrier transport layer 3a is a hole transport layer, and the second carrier transport layer 3b is an electron transport layer. In this embodiment, the photoelectric conversion layer has a passivation layer on the surface facing the electron transport layer.

[0032] The hole transport layer has the function of transporting holes generated by photoelectric conversion in the photoelectric conversion layer to the first electrode layer or the second electrode layer. As the material for the hole transport layer, known organic or inorganic materials usable for hole transport layers can be used. Organic materials that can be used as materials for the hole transport layer are not particularly limited, but include, for example, 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), polyethylenedioxythiophene:polystyrene sulfonic acid (PEDOT:PSS), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), etc. Inorganic materials that can be used as materials for the hole transport layer are not particularly limited, but include, for example, nickel oxide, copper oxide, etc.

[0033] The electron transport layer has the function of transporting electrons generated by photoelectric conversion in the photoelectric conversion layer to the first electrode layer or the second electrode layer. As the material for the electron transport layer, known organic or inorganic materials usable for electron transport layers can be used. Organic materials that can be used as the material for the electron transport layer are not particularly limited, but include, for example, fullerene compounds, phenanthroline derivatives (e.g., bathocuproine (BCP)), polyethyleneimines, etc. Examples of fullerene compounds include fullerenes (e.g., C60 fullerene, C70 fullerene) and derivatives of fullerene with substituents (e.g., [6,6]-phenyl-C 61 -Methyl butyrate (also known as PCBM or

[60] PCBM), [6,6]-phenyl-C 71 Examples include methyl butyrate (also known as PCBM or

[70] PCBM). Inorganic materials that can be used as materials for the electron transport layer include titanium dioxide, tin oxide, zinc oxide, etc.

[0034] (First electrode layer 2a and second electrode layer 2b) As materials for the first and second electrode layers, metal materials such as aluminum (Al), silver (Ag), and gold (Au), transparent conductive films such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum-doped zinc oxide (AZO), and fluorine-doped tin oxide (FTO), and carbon nanotubes, materials known as electrodes for solar cells can be used. Preferably, the materials for the first and second electrode layers are ITO, IZO, FTO, and Ag.

[0035] (Circuit board 1) The substrate 1 is a plate-shaped or film-shaped component. The material of the substrate is not particularly limited and includes, for example, inorganic materials such as glass, organic materials such as polyethylene, polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, polyamide-imide, liquid crystal polymer, and cycloolefin polymer, and metallic materials such as stainless steel and silicon. The substrate may be transparent or opaque. A transparent substrate is used when light is incident on the surface of the substrate.

[0036] <Method of manufacturing solar cells> Next, the method for manufacturing the solar cell of the present invention will be described in more detail. In the method for manufacturing the solar cell of the present invention, for example, a solar cell is manufactured by depositing a first electrode layer 2a, a first carrier transport layer 3a, a photoelectric conversion layer 4, a second carrier transport layer 3b, and a second electrode layer 2b on a substrate 1 in the order described above. The manufacturing method of the present invention is characterized by the film deposition process of the photoelectric conversion layer 4 (particularly the film deposition process of the passivation layer), and the film deposition processes for the other parts can be carried out using the same methods as conventional photoelectric conversion elements.

[0037] The following describes in detail the film formation process for the photoelectric conversion layer 4. As mentioned above, the photoelectric conversion layer 4 of the present invention has a passivation layer on its surface. The film formation process for the photoelectric conversion layer 4 of the present invention includes a step of applying a precursor solution to a coating surface on a substrate to form a photoelectric conversion layer (step S1), and a step of forming a passivation layer on the surface of the photoelectric conversion layer (step S2). The step of forming the passivation layer (step S2) includes a step of applying a solution containing 1 mM to 9 mM of trishydroxymethylaminomethane to the surface of the photoelectric conversion layer (step S2-1), and a step of drying the applied solution (step S2-2).

[0038] In the film formation process for the photoelectric conversion layer 4, first, a precursor solution is applied to the coating surface on the substrate (step S1). In this invention, the "coating surface on the substrate" does not refer only to the surface of a layer directly laminated on the substrate, but other layers may exist between the substrate and the layer having the coating surface. In one embodiment, the surface of the first carrier transport layer 3a corresponds to the coating surface.

[0039] In step S1 according to this embodiment, a precursor solution is applied to the surface of the first carrier transport layer 3a. The precursor solution applied to the surface of the first carrier transport layer 3a forms a liquid film on the first carrier transport layer. When the solvent is removed from this liquid film, a photoelectric conversion layer is formed.

[0040] A precursor solution refers to a solution containing a perovskite compound as a solute. Perovskite compounds are as previously described in relation to solar cells. Precursor solutions can be prepared by dissolving a perovskite compound, a solvent adduct of a perovskite compound, or the raw materials of multiple perovskite compounds in a suitable solvent.

[0041] When the perovskite compound is represented by formula (1) above, the precursor solution can also be prepared by dissolving one or more compounds represented by formula (2) below and one or more compounds represented by formula (3) below in a suitable solvent. In formulas (2) and (3), A, M, and X are as defined for formula (1). AX (2) MX2(3)

[0042] Examples of solvents that can be used as solvents for the precursor solution include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone, and mixed solvents containing one or more of these. It is preferable that the solvent contains DMF and DMSO, and more preferably that it consists of DMF and DMSO.

[0043] In step S1 according to this embodiment, the surface of the first carrier transport layer 3a was the coating surface, but the coating surface in step S1 is appropriately selected according to the configuration of the solar cell C after manufacturing. The coating surface in step S1 is the surface in the solar cell C after manufacturing that the photoelectric conversion layer 4 is in contact with on the substrate side.

[0044] Any method can be used to apply the precursor solution to the coating surface, as long as it allows for the application of the precursor solution in a substantially uniform layer. Examples include spin coating, inkjet, spray, blade coating, and die coating.

[0045] Step S1 is preferably carried out under a dry air atmosphere, and more preferably under an inert gas atmosphere, from the viewpoint of the stability of the perovskite compound. Examples of inert gases include nitrogen and argon.

[0046] In step S1, after coating the precursor solution, a step of dropping a poor solvent onto the substrate coated with the precursor solution and a step of drying the precursor solution may be performed. Either one of these steps may be performed, or both may be performed.

[0047] In step S1, when the poor solvent is added dropwise, the poor solvent is added to the liquid film of the precursor solution, forming a liquid film of the precursor solution containing the poor solvent (i.e., a mixed liquid film of the precursor solution and the poor solvent). Within this liquid film, the formation of crystal nuclei of the perovskite compound is promoted. The formed crystal nuclei of the perovskite compound undergo crystal growth and become the photoelectric conversion layer 4.

[0048] Here, a poor solvent is a solvent in which the solubility of the perovskite compound is at least less than that of the solvent in the precursor solution, and more preferably a solvent in which the perovskite compound is substantially insoluble. A poor solvent is, for example, a solvent in which the solubility of the perovskite compound at 25°C (weight ratio of solute to 100g of solvent) is usually less than 1% by weight, preferably less than 0.5% by weight.

[0049] The solvents that can be used as poor solvents are not particularly limited, but include, for example, substituted aliphatic hydrocarbons such as dichloromethane and chloroform; aromatic compounds such as toluene, benzene, chlorobenzene, and tetralin; ethers such as diethyl ether and tetrahydrofuran (THF); alcohols having 3 or more carbon atoms; hydrocarbons having 4 to 10 carbon atoms; and organic solvents such as acetic acid. In this invention, aromatic compounds also include compounds that partially contain an aromatic ring. These poor solvents may be used individually or in combination of two or more. In one embodiment, the poor solvent is chlorobenzene.

[0050] Furthermore, if a drying step of the precursor solution is performed in step S1, the liquid film of the precursor solution or the liquid film of the precursor solution containing a poor solvent is heated to a predetermined temperature to promote the removal of the solvent from the liquid film and to form a photoelectric conversion layer. In the manufacturing method of the present invention, the drying step may also be called the annealing step.

[0051] In the drying process, the heating temperature is typically between 100°C and 150°C. The heating time can be appropriately selected according to the heating temperature, but is typically between 1 minute and 30 minutes.

[0052] In the film deposition process for the photoelectric conversion layer 4, following step S1 described above, a step (step S2) is performed to deposit a passivation layer on the surface of the photoelectric conversion layer. By performing step S2, a passivation layer is formed on the surface of the photoelectric conversion layer, and the manufacturing of a photoelectric conversion layer having a passivation layer on its surface is completed.

[0053] Step S2 is preferably carried out under a dry air atmosphere, and more preferably under an inert gas atmosphere, from the viewpoint of the stability of the perovskite compound contained in the photoelectric conversion layer. Examples of inert gases include nitrogen and argon.

[0054] The formation of the passivation layer includes the steps of applying a solution containing 1 mM to 9 mM trishydroxymethylaminomethane to the surface of the photoelectric conversion layer (step S2-1) and drying the applied solution (step S2-2).

[0055] In step S2-1, examples of solvents for the trishydroxymethylaminomethane solution include alcohols (such as isopropyl alcohol (IPA, also known as 2-propanol)) and aromatic hydrocarbons (such as toluene). In one embodiment, the solvent is isopropyl alcohol.

[0056] In step S2-1, the trishydroxymethylaminomethane solution can be applied by known methods. Examples of application methods include spin coating, inkjet coating, spray coating, blade coating, and die coating.

[0057] In step S2-1, the concentration of trishydroxymethylaminomethane in the solution is 1 mM (mmol / L) or more and 9 mM or less, preferably 2 mM or more and 8 mM or less. When the concentration of trishydroxymethylaminomethane in the solution is 1 mM or more, the adverse effects of crystal defects in the perovskite compound on the power generation performance can be sufficiently suppressed, and when it is 9 mM or less, the presence of excess trishydroxymethylaminomethane can be prevented. For this reason, when the concentration of trishydroxymethylaminomethane in the solution is 1 mM or more and 9 mM or less, the power generation performance of the solar cell is improved.

[0058] After step S2-1, a drying step (step S2-2) is performed to dry the applied trishydroxymethylaminomethane solution. This drying step forms a passivation layer on the surface of the photoelectric conversion layer. In this step, the trishydroxymethylaminomethane solution film is heated to remove the solvent from the film. The heating temperature is typically between 60°C and 120°C. The heating time can be appropriately selected according to the heating temperature, but is typically between 1 minute and 30 minutes.

[0059] As described above, in the solar cell manufacturing method according to this embodiment, a passivation layer is formed on the surface of the photoelectric conversion layer using a trishydroxymethylaminomethane solution of a predetermined concentration. Furthermore, the solar cell according to this embodiment has a passivation layer formed using a trishydroxymethylaminomethane solution of a predetermined concentration. With such a configuration, the power generation performance of the solar cell is improved. [Examples]

[0060] The present invention will be described in more detail below using examples. However, the technical scope of the present invention is not limited to these examples.

[0061] <Material> Substrate: A glass plate with a photolithographed ITO film (transparent conductive film) formed on its surface. Hole transport layer: PTAA Starting materials for perovskite compounds: CsI, FAI (formamidinium iodide), PbI2, PbBr2 Passivation layer: Trishydroxymethylaminomethane (Tris) Electron transport layer: PCBM

[0062] <Fabrication of solar cells> A solar cell with a passivation layer on the surface of a perovskite layer was fabricated using the following procedure. Steps 2 onward were performed inside a glove box filled with N2.

[0063] 1. Prepare the circuit board. After cleaning the circuit board, it was treated with UV ozone. 2. Formation of the hole transport layer A dehydrated chlorobenzene solution of PTAA (4.5 mg / mL) was prepared and filtered before application. This solution was spin-coated onto an ITO film on a substrate at 2000 rpm, and then annealed at 100°C to form a hole transport layer. 3. Deposition of the perovskite layer CsI, FAI, PbI2, and PbBr2 are dissolved in DMF and DMSO (DMF / DMSO = 80 / 20 vol%), and Cs 0.17 FA 0.83 PbI 2.55 Br 0.45 A 1.2 M (mol / L) solution of the composition (molar ratio) was prepared and filtered before application. This solution was spin-coated onto a hole transport layer at 4000 rpm, and chlorobenzene (a poor solvent) was added dropwise during rotation. Subsequently, the material was annealed at 120°C to deposit a perovskite layer. 4. Deposition of the passivation layer Tris anhydrous 2-propanol solutions of the specified concentrations (2 mM, 4 mM, 8 mM, 10 mM, 12 mM) were prepared and filtered before application. Each prepared solution was spin-coated onto a perovskite layer at 3000 rpm, and then annealed at 80°C to form a passivation layer. 5. Formation of electron transport layer A dehydrated 2-propanol solution of PCBM (25 mg / mL) was prepared and filtered before application. This solution was spin-coated onto a passivation layer at 1500 rpm to form an electron transport layer. 6. Deposition of the electrode layer Ag (100 nm thick) was deposited on the electron transport layer by vacuum deposition and then patterned using a metal mask.

[0064] A solar cell without a passivation layer on the surface of the perovskite layer was fabricated in the same manner as above, except that the deposition of the passivation layer in step 4 was not performed.

[0065] <Rating> IV measurement Solar cells fabricated by depositing a passivation layer with varying concentrations of Tris solution (Tris concentration) were subjected to IV measurements. Specifically, a solar simulator was used to measure the light intensity at 1000 W / m². 2 The solar cell characteristics were measured using a source meter after irradiating it with light, and the power generation efficiency was determined. The power generation efficiency is shown as a relative ratio to the power generation efficiency when the Tris concentration is 0 mM (without a passivation layer).

[0066] Figure 3 shows the relationship between Tris concentration and power generation efficiency. As shown in Figure 3, the power generation efficiency of the solar cell improved in the Tris concentration range of 1 mM to 9 mM. [Explanation of Symbols]

[0067] 1: Substrate, 2a: First electrode layer, 2b: Second electrode layer, 3a: First carrier transport layer, 3b: Second carrier transport layer, 4: Photoelectric conversion layer, 4a: Perovskite layer, 4b: Passivation layer, C: Solar cell

Claims

1. A method for manufacturing a solar cell having a photoelectric conversion layer containing a perovskite compound, The process involves applying a precursor solution containing the perovskite compound as a solute to a coating surface on a substrate to form the photoelectric conversion layer, A step of forming a passivation layer on the surface of the photoelectric conversion layer. Includes, The step of forming the passivation layer is The steps include applying a solution containing 1 mM to 9 mM trishydroxymethylaminomethane to the surface of the photoelectric conversion layer, A step of drying the applied solution and A method for manufacturing solar cells, including

2. The perovskite compound is given by the following formula (1) AMX ３ (1) (In the formula, A is at least one selected from cesium ions, methylammonium ions, and formamidinium ions. M is at least one selected from divalent lead ions and tin ions. X is at least one selected from halogen ions. A method for manufacturing a solar cell according to claim 1, as represented by [the formula shown].

3. A solar cell having a hole transport layer, a photoelectric conversion layer containing a perovskite compound, and an electron transport layer, The photoelectric conversion layer is disposed between the hole transport layer and the electron transport layer. The photoelectric conversion layer has a passivation layer on its surface, The passivation layer is formed using a solution containing 1 mM to 9 mM trishydroxymethylaminomethane. Solar cell.

4. The solar cell according to claim 3, wherein the photoelectric conversion layer has a passivation layer on the surface facing the electron transport layer.

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