Perovskite solar cell and preparation method thereof, photovoltaic module, system and power utilization device

Abstract

The invention relates to a perovskite solar cell and a preparation method thereof, a photovoltaic module, a system and an electric device. The perovskite solar cell comprises a transparent electrode layer, and a perovskite layer, an electron transport layer and a metal electrode which are sequentially arranged on the transparent electrode layer; the electron transport layer comprises an organic electron transport material, a first additive and a second additive; the first additive is prepared from one or more of polymethyl methacrylate, a methacrylic acid-methyl methacrylate copolymer, a 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly (4-vinylpyridine); the second additive comprises one or more of a compound shown as a formula I and a compound shown as a formula II. The perovskite solar cell provided by the invention has relatively high photoelectric conversion efficiency and relatively good stability.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell, a photovoltaic module, a system and an electrical device. Background Art

[0002] With the rapid development of new energy, solar cells have been widely used in industry, commerce, agriculture, communications and other fields. Perovskite solar cells (PSCs) are devices that use the photoelectric conversion mechanism of perovskite crystal materials to convert solar energy into electrical energy. They are the third generation of solar cells and have many advantages such as high photoelectric conversion efficiency, simple manufacturing process and low production cost. They have been widely studied in recent years.

[0003] With the maturity of the process and the continuous reduction of prices of organic electron transport layer materials such as fullerene derivatives, naphthalene diimide and perylene diimide, organic electron transport layer materials are gradually suitable for industrial large-scale production. Organic electron transport layer materials can improve the hysteresis phenomenon of devices and improve the photoelectric conversion efficiency of devices to a certain extent; however, the photoelectric conversion efficiency of perovskite solar cells using organic electron transport layer materials still needs to be further improved, and the stability of the cells is poor.

[0004] Therefore, how to improve the photoelectric conversion efficiency and stability of perovskite solar cells using organic materials as electron transport layers is one of the key issues to be urgently addressed in this field. Summary of the invention

[0005] The present application is made in view of the above-mentioned problems, and one of its purposes is to provide a perovskite solar cell having higher photoelectric conversion efficiency and better stability.

[0006] In order to achieve the above-mentioned object, the first aspect of the present application provides a perovskite solar cell, comprising a transparent electrode layer and a perovskite layer, an electron transport layer and a metal electrode sequentially arranged on the transparent electrode layer;

[0007] The electron transport layer includes an organic electron transport material, a first additive and a second additive;

[0008] The first additive comprises one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly-4-vinylpyridine;

[0009] The second additive comprises one or more of the following compounds of formula I and formula II:

[0010]

[0011] Wherein, R1, R2, R3, R5 and R6 are independently selected from C1-C4 alkyl groups; n1 and n2 are independently integers of 1-6; m1 and m2 are independently integers of 1-4; R4 and R7 are independently C1-C5 alkyl groups, C1-C5 alkoxy groups, C1-C5 alkylthiol groups, aryl groups, halogen groups, carboxyl groups, cyano groups or do not exist; X is one or more of Cl, Br, I, BF4, PF6 and TFSI; Y1 and Y2 are independently selected from any one of C, N, O and S or do not exist.

[0012] The perovskite solar cell of the present application adds a specific organic polymer as the first additive in the electron transport layer using organic electron transport material, and adds a specific quaternary ammonium salt and / or tertiary amine molecule as the second additive. The introduction of the organic polymer first additive can improve the dispersibility of the organic electron transport material in the solution forming the electron transport layer, improve the film uniformity of the electron transport layer, and reduce the entry channel of water molecules in the electron transport layer; the quaternary ammonium salt second additive can significantly improve the film conductivity of the electron transport layer; the tertiary amine molecule second additive can improve the binding force between the molecules of the organic electron transport material; the above-mentioned quaternary ammonium salt and tertiary amine molecules can form a passivation layer with the perovskite interface during the molecular crystallization process of the electron transport layer to reduce the diffusion of perovskite ions. Through the combined action of the above-mentioned specific first additive and the second additive, the photoelectric conversion efficiency and stability of the perovskite solar cell can be improved.

[0013] In any embodiment, based on the total mass of the electron transport layer, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%. In this way, the photoelectric conversion efficiency and stability of the perovskite solar cell can be further improved.

[0014] In any embodiment, the second additive comprises the compound of formula I and the compound of formula II, and the mass ratio of the compound of formula I to the compound of formula II is (0.5-2): 1. In this way, the photoelectric conversion efficiency and stability of the perovskite solar cell can be further improved.

[0015] In any embodiment, the compound of formula I comprises one or more of tetrabutylammonium tetrafluoroborate, hexamethonium iodide, and dodecyltrimethylammonium bromide.

[0016] In any embodiment, the compound of formula II includes one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

[0017] In any embodiment, the thickness of the electron transport layer is 25 nm to 45 nm.

[0018] In any embodiment, the organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, perylene diimide and its derivatives.

[0019] A second aspect of the present application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0020] providing the transparent electrode layer; and

[0021] forming the perovskite layer, the electron transport layer and the metal electrode in sequence on the transparent electrode layer;

[0022] The solution for forming the electron transport layer includes a solvent and a solute dispersed in the solvent, and the solute includes the organic electron transport material, the first additive and the second additive.

[0023] By adding the specific first additive and the second additive to the solution of the electron transport layer, the photoelectric conversion efficiency and stability of the perovskite solar cell can be improved.

[0024] In any embodiment, the solvent includes a first organic solvent and a second organic solvent, the boiling point of the first organic solvent is 38°C to 90°C, and the boiling point of the second organic solvent is 110°C to 210°C. In this way, the first organic solvent is a low boiling point solvent, and the second organic solvent is a high boiling point solvent. The organic electron transport material, the first additive and the second additive are dispersed in the mixed solvent system using the mixed solvent of the first organic solvent and the second organic solvent, which can optimize the crystallization order and uniformity of the organic electron transport material molecules and the first additive and the second additive, guide the molecular orientation, enhance the film quality and conductivity of the electron transport layer, and improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0025] In any embodiment, the first organic solvent includes one or more of chloroform, dichloromethane and tetrahydrofuran.

[0026] In any embodiment, the second organic solvent includes one or more of chlorobenzene, o-dichlorobenzene, toluene, o-xylene, anisole, 2-methylanisole, 2-chlorophenol and 1,2,3,4-tetralin.

[0027] In any embodiment, based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%.

[0028] In any embodiment, based on the total mass of the solution, the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

[0029] In any embodiment, based on the total mass of the solute, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

[0030] The third aspect of the present application provides a photovoltaic module, comprising the perovskite solar cell of the first aspect of the present application.

[0031] A fourth aspect of the present application provides a photovoltaic system, comprising the photovoltaic assembly of the third aspect of the present application.

[0032] The fifth aspect of the present application provides an electrical device, comprising the perovskite solar cell of the first aspect of the present application.

[0033] The perovskite solar cell of the present application can effectively improve the photoelectric conversion efficiency and stability of the perovskite solar cell using organic electron transport materials as the electron transport layer by adding a specific organic polymer as the first additive in the electron transport layer using organic electron transport materials, and adding specific quaternary ammonium salts and / or tertiary amine molecules as the second additive. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to better describe and illustrate the embodiments or examples of those applications disclosed herein, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered as limiting the scope of any of the disclosed applications, the embodiments or examples currently described, and the best modes of these applications currently understood. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the accompanying drawings:

[0035] Figure 1 A schematic diagram of the structure of a perovskite solar cell according to an embodiment of the present application;

[0036] Figure 2 It is a schematic structural diagram of an electrical device according to one embodiment of the present application.

[0037] Description of reference numerals:

[0038] 1. Perovskite solar cell; 2. Electrical device; 11. Transparent electrode layer; 12. Hole transport layer; 13. Perovskite layer; 14. Electron transport layer; 15. Metal electrode. DETAILED DESCRIPTION

[0039] Below, some embodiments of the perovskite precursor solution, perovskite film, perovskite solar cell and electrical device of the present application are disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following descriptions are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0040] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9 and 10.

[0041] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0042] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0043] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0044] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". Further, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0045] In this application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0046] In the present application, "plurality", "multiple" and the like, unless otherwise specified, refer to a number greater than or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0047] As used herein, "combination thereof", "any combination thereof", "any combination thereof" etc. include all suitable combinations of any two or more of the listed items.

[0048] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the technical solution that can implement the present application.

[0049] Herein, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of this application. If multiple "preferred" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "preferred" item is independent.

[0050] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0051] In the present application, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0052] In the present application, the term "room temperature" generally refers to 4°C to 35°C, and may refer to 20°C±5°C. In some embodiments of the present application, room temperature refers to 20°C to 30°C.

[0053] In this application, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left endpoint and the right endpoint are the same. For example, 3h~5h or 3h~5h both mean that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0054] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Furthermore, the weight described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0055] Herein, unless otherwise specified, "alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, a secondary carbon atom, a tertiary carbon atom, a quaternary carbon atom, or a combination thereof. Phrases containing this term, for example, "C1-9 alkyl" refers to an alkyl containing 1 to 9 carbon atoms, and each occurrence may be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl or C9 alkyl. Suitable examples include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(C H3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (- CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(CH3)CH( 2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3 and octyl (-(CH2)7CH3).

[0056] Herein, if not otherwise specified, "heteroalkyl" means that at least one carbon atom is replaced by a non-carbon atom on the basis of an alkyl group, and the non-carbon atom can be an N atom, an O atom, an S atom, a P atom, etc. It is described below with O, N, and S as examples. For example, if the carbon atom connected to the adjacent group in the alkyl group is replaced by a non-carbon atom O, N, or S, the obtained heteroalkyl group is an alkoxy group (e.g., -OCH3, etc.), an amino group (e.g., -NHCH3, -N(CH3)2, etc.) or a thioalkyl group (e.g., -SCH3). If the carbon atom not directly connected to the adjacent group in the alkyl group is replaced by a non-carbon atom O, N, or S, the obtained heteroalkyl group is an alkoxyalkyl group (e.g., -CH2CH2-O-CH3, etc.), an alkylaminoalkyl group (e.g., -CH2NHCH3, -CH2N(CH3)2, etc.) or an alkylthioalkyl group (e.g., -CH2-S-CH3). If the terminal carbon atom of an alkyl group is replaced by a non-carbon atom, the resulting heteroalkyl group can be a hydroxyalkyl group (e.g., -CH2CH2-OH), an aminoalkyl group (e.g., -CH2NH2), or a mercaptoamino group (e.g., -CH2CH2-SH). Phrases containing the term "heteroalkyl" such as "C1-C9 heteroalkyl" or "C 1-9 “Heteroalkyl” refers to a heteroalkyl group containing 1 to 9 carbon atoms, which at each occurrence may be independently C1 heteroalkyl, C2 heteroalkyl, C3 heteroalkyl, C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl or C9 heteroalkyl.

[0057] In this article, unless otherwise specified, "cycloalkyl" has the same meaning as "non-aromatic cycloalkyl", which refers to a monovalent residue formed by a non-aromatic hydrocarbon (saturated hydrocarbon or unsaturated hydrocarbon) containing a ring carbon atom losing a hydrogen atom on the ring, that is, a monovalent connection site is directly formed on the ring. Cycloalkyl derived from non-aromatic saturated hydrocarbons can be recorded as saturated cycloalkyl, and cycloalkyl derived from non-aromatic unsaturated hydrocarbons can be recorded as unsaturated cycloalkyl. Cycloalkyl can be a monocyclic alkyl, a spirocyclic alkyl, or a bridged cycloalkyl. Phrases containing this term, for example, "C3-C9 cycloalkyl" or C 3-9 "Cycloalkyl" refers to a cycloalkyl group containing 3 to 9 carbon atoms, each occurrence of which can be independently C3 cycloalkyl, C4 cycloalkyl, C5 cycloalkyl, C6 cycloalkyl, C7 cycloalkyl, C8 cycloalkyl or C9 cycloalkyl. Suitable examples include, but are not limited to: cyclopropyl Cyclobutyl Cyclopentyl Cyclohexyl In addition, "cycloalkyl" may also contain one or more double bonds, and representative examples of cycloalkyl containing double bonds include cyclopentenyl (including but not limited to ), cyclohexenyl (including but not limited to ), cyclohexadiene (including but not limited to ) yl, cyclopentadienyl (including but not limited to ) and cyclobutadienyl (including but not limited to ).

[0058] Herein, unless otherwise specified, "heterocycloalkyl" means that at least one carbon atom is replaced by a non-carbon atom on the basis of a cycloalkyl group, and the non-carbon atom may be an N atom, an O atom, an S atom, etc., and may be a saturated ring or a partially unsaturated ring. Phrases containing this term, for example, "C4-C9 heterocyclyl" means a heterocyclyl group containing 4 to 9 carbon atoms, and each occurrence may be independently C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl or C9 heteroalkyl. Suitable examples include, but are not limited to: dihydropyridyl, tetrahydropyridyl (piperidyl), tetrahydrothienyl, sulfur-oxidized tetrahydrothienyl, tetrahydrofuranyl, tetrahydroquinolyl, tetrahydroisoquinolyl, dihydroindole.

[0059] In this article, unless otherwise specified, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic hydrocarbon compound by losing a hydrogen atom, that is, a monovalent connection site formed directly on the ring, which can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. For example, "C6-C 10 "Aryl" refers to an aromatic group containing 6 to 10 carbon atoms, each occurrence of which can be independently C6 aryl, C8 aryl, C9 aryl or C 10 Aryl. For example, "C6~C 20 "Aryl" refers to an aromatic group containing 6 to 20 carbon atoms, and each occurrence can be independently but not limited to C6 aryl aryl (such as phenyl), C6 aryl aryl (such as benzocyclobutenyl), C8 aryl (such as phenylcyclobutenyl), C9 aryl (such as indenyl), C 10 Aryl (such as naphthyl), C 12 Aryl (such as acenaphthenyl, biphenyl), C 13 Aryl (such as fluorenyl), C 14 Aryl (such as anthracenyl, phenanthrenyl), C 18 Aryl (such as triphenylene) or C 20 Aryl (eg, perylene). Examples of suitable aromatic cyclic hydrocarbon compounds include, but are not limited to, benzene, stycyclobutene, biphenyl, indene, naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, triphenylene, perylene, and derivatives thereof.

[0060] Herein, unless otherwise specified, "heteroaryl" refers to an aromatic heterocyclic group, which may be a monovalent group formed by replacing at least one carbon atom of an aryl group with a non-carbon atom, or a monovalent group formed by replacing at least one carbon atom of a cyclopentadienyl group with a non-carbon atom, wherein the non-carbon atom may be, but is not limited to, a N atom, an O atom, or a S atom. For example, "C1-C 10 The term "heteroaryl" refers to a heteroaryl group containing 1 to 10 carbon atoms, and each occurrence may be independently C1 heteroaryl (such as tetrazolyl, etc.), C2 heteroaryl (such as triazolyl, oxadiazolyl, etc.), C3 heteroaryl (such as imidazolyl, etc.), C4 heteroaryl (such as furanyl, etc.), C5 heteroaryl (such as pyridyl, etc.), C6 heteroaryl, C7 heteroaryl (such as benzimidazole, etc.), C8 heteroaryl (such as indolyl, etc.), C9 heteroaryl (such as quinolyl, etc.) or C 10 Heteroaryl (such as pyrrolobipyridinyl). Also for example, "C3~C 20 "Heteroaryl" refers to a heteroaryl group containing 3 to 20 carbon atoms, each occurrence of which can be independently but not limited to C2 heteroaryl, C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C8 heteroaryl, C9 heteroaryl, C 10 Heteroaryl, C 12 Heteroaryl, C 13 Heteroaryl, C 14 Heteroaryl, C 18 Heteroaryl or C 20 Heteroaryl. Suitable examples include, but are not limited to, heteroaryl groups derived from the following heteroaromatic rings (with the number of carbon atoms in parentheses): furan (C4), benzofuran (C8), thiophene (C4), benzothiophene (C8), pyrrole (C4), pyrazole (C3), triazole (C2), imidazole (C3), oxazole (C3), oxadiazole (C2), thiazole (C3), tetrazole (C1), indole (C8), carbazole (C 12 ), pyrroloimidazole (C5), pyrrolopyrrole (C6), thienopyrrole (C6), thienothiophene (C6), furopyrrole (C6), furofuran (C6), thienofuran (C6), thienopyridine (C7), furopyridine (C7), benzoxazole (C7), benzisoxazole (C7), benzothiazole (C7), benzisothiazole (C7), benzimidazole (C7), pyridine (C5), pyrazine (C4), pyridazine (C4), pyrimidine (C4), triazine (C3), quinoline (C9), isoquinoline (C9), naphthyridine (C8, such as o-naphthyridine), quinoxaline (C8), phenanthridine (C 13 ), primidium (C 11 ), quinazoline (C8) and quinazolinone (C8).

[0061] Herein, unless otherwise specified, "alkylene" refers to a hydrocarbon group having two monovalent radical centers derived from an alkane by removing two hydrogen atoms (or derived from an alkyl group by losing another hydrogen atom), which may be a saturated branched alkyl group or a saturated straight-chain alkyl group. For example, "C1-C9 alkylene" means that the alkyl portion contains 1 to 9 carbon atoms, and each occurrence may be independently C1 alkylene, C2 alkylene, C3 alkylene, C4 alkylene, C5 alkylene, C6 alkylene, C7 alkylene, C8 alkylene or C9 alkylene. Suitable examples include, but are not limited to, methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-) and 1,4-butyl (-CH2CH2CH2CH2-)

[0062] As used herein, "halogen" or "halo" refers to F, Cl, Br or I unless otherwise specified.

[0063] As used herein, unless otherwise specified, "amino" may be a primary amino group (-NH2), a secondary amino group (>NH), a tertiary amino group (>N-) or a quaternary amino group (>N + <).

[0064] Herein, unless otherwise specified, a hydroxyl group is -OH, a carboxyl group is -COOH, a cyano group is -CN, a hydrazine group is -NHNH2, a sulfinic acid group is -S(=O)OH, a phosphinic acid group is (*-)2P(=O)OH, a sulfonic acid group is -S(=O)2OH, a phosphate group is (*-)P(=O)(OH)2, and a boric acid group is (*-)B(OH)2. In which, the * in the phosphinic acid group indicates that it is connected to a carbon atom or H and at least one is connected to a carbon atom, the * in the phosphonic acid group indicates that it is connected to a carbon atom, and the * in the boric acid group indicates that it is connected to a carbon atom.

[0065] At present, the photoelectric conversion efficiency of perovskite solar cells using organic electron transport layer materials still needs to be further improved, and the stability of the cells is poor, which limits the industrial large-scale production of perovskite solar cells using organic electron transport layers. This application proposes a perovskite solar cell, which can effectively improve the photoelectric conversion efficiency and stability of the perovskite solar cell by adjusting the material composition of the organic electron transport layer.

[0066] See also Figure 1In one embodiment of the present application, a trans-structured perovskite solar cell 1 is provided. The perovskite solar cell 1 comprises a transparent electrode layer 11 and a hole transport layer 12, a perovskite layer 13, an electron transport layer 14 and a metal electrode 15 sequentially arranged on the transparent electrode layer 11.

[0067] The electron transport layer 14 includes an organic electron transport material, a first additive and a second additive; the first additive includes one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly-4-vinylpyridine;

[0068] The second additive includes one or more of the following compounds of formula I and formula II:

[0069]

[0070] Wherein, R1, R2, R3, R5 and R6 are independently selected from C1-C4 alkyl groups; n1 and n2 are independently integers of 1-6; m1 and m2 are independently integers of 1-4; R4 and R7 are independently C1-C5 alkyl groups, C1-C5 alkoxy groups, C1-C5 alkylthiol groups, aryl groups, halogen groups, carboxyl groups, cyano groups or do not exist; X is one or more of Cl, Br, I, BF4, PF6 and TFSI; Y1 and Y2 are independently selected from any one of C, N, O and S or do not exist.

[0071] The conventional perovskite solar cell 1 using organic electron transport layer materials has poor conductivity, which limits the photovoltaic performance of the perovskite solar cell 1 and the photoelectric conversion efficiency of the cell. At the same time, the organic electron transport material has poor dispersion in the solvent and agglomeration is serious, which affects the uniformity of the film of the electron transport layer 14, resulting in poor stability of the cell using the organic electron transport material as the electron transport layer 14. The above factors hinder the large-scale application of the perovskite solar cell 1 using organic electron transport materials as the electron transport layer 14 in the industry.

[0072] The perovskite solar cell 1 mentioned above in the present application, adds a specific organic polymer as the first additive in the electron transport layer 14 using organic electron transport materials, and adds a specific quaternary ammonium salt and / or tertiary amine molecule as the second additive. Among them, the introduction of the above-mentioned organic polymer can improve the dispersibility of the organic electron transport material in the solution forming the electron transport layer 14, reduce the agglomeration of the organic electron transport material, and can improve the film uniformity of the electron transport layer 14, thereby improving the photoelectric conversion efficiency of the device; the introduction of the above-mentioned quaternary ammonium salt can significantly improve the film conductivity of the electron transport layer 14, thereby improving the photoelectric conversion efficiency of the perovskite solar cell; the introduction of the above-mentioned tertiary amine molecules can improve the binding force with the transport layer molecules through the combination of N atoms and PCBM, improve the molecular orientation, and enhance the PCBM electron mobility.

[0073] In addition, the hydrophobic functional groups in the above-mentioned organic polymer can reduce the entry channels of water molecules in the electron transport layer 14, alleviate the reaction of water with perovskite through the electron transport layer 14, and thus improve the stability of the device; the above-mentioned quaternary ammonium salt and tertiary amine molecules can form a passivation layer with the perovskite interface during the molecular crystallization of the electron transport layer 14 to reduce the diffusion of perovskite ions, inhibit the decomposition of perovskite, and improve the stability of the device. Through the combined action of the above-mentioned specific first additive and the second additive, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 using organic electron transport materials can be effectively improved.

[0074] It can be understood that the electron transport layer 14 of the perovskite solar cell 1 may include only organic electron transport materials, the above-mentioned first organic polymer additive and the above-mentioned second quaternary ammonium salt additive; may include only organic electron transport materials, the above-mentioned first organic polymer additive and the above-mentioned second tertiary amine molecule additive; and may also include organic electron transport materials, the above-mentioned first organic polymer additive, the above-mentioned second quaternary ammonium salt additive and the above-mentioned second tertiary amine molecule additive at the same time.

[0075] It can be understood that R1, R2, R3, R5 and R6 in the above-mentioned compounds of formula I and formula II can be independently methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, tert-butyl, etc.; n1 and n2 can be independently 1, 2, 3, 4, 5; m1 and m2 can be independently 1, 2, 3, 4.

[0076] In some embodiments, based on the total mass of the electron transport layer 14, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%. The amount of the first additive, the second additive, and the organic electron transport material in the electron transport layer 14 is within the above range, which can further improve the photoelectric conversion efficiency and stability of the perovskite solar cell 1.

[0077] In some embodiments, the second additive includes a compound of formula I and a compound of formula II, and the mass ratio of the compound of formula I to the compound of formula II is (0.5-2): 1. In this way, two types of second additives, the compound of formula I and the compound of formula II, are simultaneously used in the electron transport layer 14, and the mass ratio of the compound of formula I to the compound of formula II is controlled within the range of (0.5-2): 1. Through the interaction of a specific amount of the second additive of quaternary ammonium salt, the second additive of tertiary amine molecule, and the first additive of organic polymer with the organic electron transport material, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 can be further improved.

[0078] In some of the embodiments, the compound of formula I is one or more of tetrabutylammonium tetrafluoroborate, hexamethylammonium iodide, and dodecyltrimethylammonium bromide; the compound of formula II is one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

[0079] In some embodiments, the thickness of the electron transport layer is 25 nm to 45 nm. It is understood that the thickness of the electron transport layer can be, but is not limited to, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, and 45 nm.

[0080] In some embodiments, the organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, perylene diimide and its derivatives. Among them, the fullerene derivative can be PCBM ([6,6]-phenyl-C61-butyric acid isomethyl ester), C 60 -PDI(C 60 -perylene diimide) etc.

[0081] In some embodiments, the transparent conductive layer 11 may be made of conductive glass, such as FTO (fluorine-doped tin oxide, SnO2:F) glass. The transparent conductive layer 11 may be used as a device substrate when preparing the perovskite solar cell 1. The hole transport layer 12 may be made of a hole transport material commonly used in the art. In a specific example, the hole transport layer 12 uses PTAA (polytriarylamine). The perovskite layer 13 may be made of a perovskite component commonly used in the art. In a specific example, the perovskite component uses Cs0.05 MA 0.1 FA 0.85 PbI3; wherein MA is methylammonium, and FA is formamidine. The metal electrode 15 can be an electrode commonly used in the art. In a specific example, the metal electrode 15 is an Ag electrode.

[0082] An embodiment of the present application provides a method for preparing the above-mentioned perovskite solar cell 1, and the preparation method includes the following steps S100 to S500:

[0083] Step S100: providing a transparent electrode layer 11 .

[0084] The transparent electrode layer 11 is used as a device substrate. Specifically, the transparent electrode layer 11 can be made of FTO glass. Before preparing the hole transport layer 12 on the transparent electrode layer 11, the transparent electrode layer 11 is firstly subjected to UV cleaning treatment to remove impurities on the surface of the transparent electrode layer 11.

[0085] In a specific example, the transparent electrode layer 11 is made of FTO glass.

[0086] Step S200 : forming a hole transport layer 12 on the transparent electrode layer 11 .

[0087] A solution containing a hole transport material is spin-coated on one surface of the transparent electrode layer 11 by a spin-coating process, and the hole transport layer 12 is formed after annealing.

[0088] The spin coating process parameters (such as spin coating speed, spin coating time, etc.) when preparing the hole transport layer 12 can be specifically set according to the actual conditions such as the thickness of the hole transport layer 12 to be prepared. Similarly, the annealing temperature can also be set according to the actual production conditions.

[0089] It is understood that the material forming the hole transport layer 12 may be a conventional hole transport material in the art.

[0090] In a specific example, the hole transport material is PTAA, the spin coating speed is 5000 rpm / s, the spin coating time is 30 s, and the annealing temperature is 100°C.

[0091] Step S300 : forming a perovskite layer 13 on the hole transport layer 12 .

[0092] A solution containing a perovskite component is spin-coated on the surface of the hole transport layer 12 away from the transparent electrode layer 11 by a spin-coating process, and the perovskite layer 13 is formed after annealing.

[0093] The spin coating process parameters (such as spin coating speed, spin coating acceleration, spin coating time, etc.) when preparing the perovskite layer 13 can be specifically set according to the actual conditions such as the thickness of the perovskite layer 13 to be prepared. The annealing temperature can also be set according to the actual production conditions.

[0094] It can be understood that the perovskite layer 13 can adopt the perovskite components commonly used in the art.

[0095] In a specific example, the perovskite component is Cs 0.05 MA 0.1 FA 0.85 PbI3, spin coating speed is 5000rpm / s, spin coating acceleration is 2000rpm / s, spin coating time is 30s, and annealing temperature is 100℃.

[0096] Step S400 : forming an electron transport layer 14 on the perovskite layer 13 .

[0097] The electron transport layer 14 can be formed without annealing by spin coating a solution containing an organic electron transport material, a first additive, and a second additive on the surface of the perovskite layer 13 away from the hole transport layer 12 using a spin coating process. The solution includes a solvent and a solute dispersed in the solvent, wherein the solute includes an organic electron transport material, a first additive, and a second additive. The types of the organic electron transport material, the first additive, and the second additive in the electron transport layer 14 are as described above and will not be repeated here.

[0098] It is understood that the spin coating process parameters (such as spin coating speed, spin coating time, etc.) when preparing the electron transport layer 14 can be specifically set according to the actual situation such as the thickness of the electron transport layer 14 to be prepared. The electron transport layer 14 can be made of organic electron transport materials commonly used in the art.

[0099] In a specific example, the spin coating speed is 2000 rpm / s, the spin coating time is 30 s, and the organic electron transport material is PCBM.

[0100] In some embodiments, the solvent in the solution for forming the electron transport layer 14 includes a first organic solvent and a second organic solvent, wherein the first organic solvent is a low boiling point solvent with a boiling point of 38°C to 70°C, and the second organic solvent is a high boiling point solvent with a boiling point of 110°C to 210°C.

[0101] In some embodiments, the first organic solvent includes one or more of chloroform (boiling point of about 61° C.), dichloromethane (boiling point of about 39.75° C.), and tetrahydrofuran (boiling point of about 66° C.). The second organic solvent includes one or more of chlorobenzene (boiling point of about 132.2° C.), o-dichlorobenzene (boiling point of about 180.4° C.), toluene (boiling point of about 110.6° C.), o-xylene (boiling point of about 144.4° C.), anisole (boiling point of about 153.8° C.), 2-methylanisole (boiling point of about 170° C.), 2-chlorophenol (boiling point of about 174° C.), and 1,2,3,4-tetrahydronaphthalene (boiling point of about 207.2° C.).

[0102] In some of the embodiments, based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%. It is understood that the volume fraction of the first organic solvent can be but not limited to 20%, 30%, 40%, 50%, 60%, 70%, 80%; accordingly, the volume fraction of the second organic solvent can be but not limited to 80%, 70%, 60%, 50%, 40%, 30%, 20%. In a specific example, the volume ratio of the first organic solvent to the second organic solvent is 1:1, that is, the high boiling point solvent and the low boiling point solvent are mixed in equal volumes, and the volume fractions are both 50%.

[0103] In some embodiments, in the solution for forming the electron transport layer 14, the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

[0104] In some embodiments, in the solute forming the electron transport layer 14, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

[0105] Step S500 : forming a metal electrode 15 on the electron transport layer 14 .

[0106] The metal electrode 15 is prepared on the electron transport layer 14 by a thermal evaporation process, wherein the evaporation rate of the thermal evaporation process can be set according to actual needs; the material of the metal electrode 15 can also be the electrode material commonly used in the art.

[0107] In one specific example, the evaporation rate is A metal Ag electrode with a thickness of 110 nm was prepared.

[0108] The preparation method of the perovskite solar cell 1 of the present application uses a spin coating process to spin-coat a solution containing an organic electron transport material, a first additive, and a second additive on the perovskite layer 13 to prepare an electron transport layer 14. By using the first additive and the second additive specified in the present application in the electron transport layer 14, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 can be effectively improved.

[0109] Furthermore, by using a mixed solvent including a first organic solvent and a second organic solvent, the first organic solvent is a low boiling point solvent, and the second organic solvent is a high boiling point solvent, the first organic solvent and the second organic solvent are mixed in a specific volume ratio; the organic electron transport material, the first additive and the second additive are dispersed in the mixed solvent system. By adjusting the volume ratio of different solvents by the difference in boiling point and viscosity (generally, the viscosity of solvents with high boiling points is also large, and the viscosity of solvents with low boiling points is also small) of the first organic solvent and the second organic solvent, the crystallization order and uniformity of the organic electron transport material molecules and the first additive and the second additive can be optimized, and the molecular orientation can be guided, so that the film quality and conductivity of the electron transport layer 14 can be enhanced, and the photoelectric conversion efficiency and stability of the perovskite solar cell 1 can be improved.

[0110] An embodiment of the present application provides a photovoltaic module, including the perovskite solar cell of the present application. The photovoltaic module of the present application has high photoelectric conversion efficiency and good stability by adopting the perovskite solar cell of the present application.

[0111] The above-mentioned photovoltaic module includes one or more perovskite solar cells, which can be selected according to the specific application scenario; further, the above-mentioned photovoltaic module includes multiple perovskite solar cells, and the multiple perovskite solar cells are connected in series or in parallel to form a battery cell.

[0112] In some of the embodiments, the photovoltaic module further includes a photovoltaic glass layer, a bonding layer and a back sheet.

[0113] Adhesive layers are respectively arranged on the two surfaces of the cell, a back plate is arranged on the surface of one of the adhesive layers away from the cell, and a photovoltaic glass layer is arranged on the surface of the other adhesive layer away from the cell.

[0114] The photovoltaic glass layer and the back panel are used to protect the perovskite solar cells, and they have the functions of sealing, insulation and waterproofing; the bonding layer plays the role of bonding the photovoltaic glass layer to the battery cell, and bonding the back panel to the battery cell.

[0115] Optionally, the photovoltaic glass layer is made of tempered glass, the back panel is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0116] Furthermore, the above photovoltaic assembly also includes a junction box and an outer frame.

[0117] The junction box is used to protect the power generation system of the entire photovoltaic module. It is equivalent to a current transfer station. When a battery cell short-circuits, the junction box will automatically disconnect the short-circuited battery string.

[0118] The outer frame can support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0119] Furthermore, the connection between the frame and other parts of the photovoltaic module is bonded and sealed by silicone. The photovoltaic module can convert solar energy into electrical energy, or send it to a battery for storage, or drive a load to work.

[0120] In some embodiments, the photovoltaic component is a solar panel.

[0121] An embodiment of the present application provides a photovoltaic system, including the photovoltaic assembly described above.

[0122] The photovoltaic system utilizes the perovskite solar cells in the above photovoltaic modules to directly convert solar radiation energy into electrical energy with high efficiency and good stability; further, the above photovoltaic system is a photovoltaic power generation system.

[0123] Photovoltaic modules are the core part of photovoltaic power generation systems. The above photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios; further, when the above photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0124] The above photovoltaic system can be an independent photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0125] An independent photovoltaic power generation system includes a photovoltaic array, a battery pack, a charging controller, a power electronic converter (inverter), a load, etc. Its working principle is that the solar radiation energy is first converted into electrical energy through the photovoltaic array, and then converted by the power electronic converter to supply power to the load. At the same time, the excess electrical energy is stored in the energy storage device in the form of chemical energy after passing through the charging controller. In this way, when the sunshine is insufficient, the energy stored in the battery can be converted into AC 220V, 50Hz electrical energy after being stepped up by the power electronic inverter, filtering and power frequency transformer for use by the AC load.

[0126] The grid-connected photovoltaic power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter) and system monitoring. Its working principle is that the solar radiation energy is converted by the photovoltaic array, and then converted into high-voltage DC power by high-frequency DC conversion, and then inverted by the power electronic inverter to output a sinusoidal AC current with the same frequency as the grid voltage to the grid.

[0127] The above two photovoltaic power generation systems have their own characteristics and can be selected according to specific application scenarios.

[0128] See also Figure 2 In one embodiment of the present application, there is provided an electrical device 2, which includes the perovskite solar cell described above in the present application.

[0129] In some embodiments, the power-consuming device 2 is a common device including the solar cell of the present application, such as in the fields of communication, transportation, industry and agriculture, lighting, etc. The power-consuming device 2 may include, for example, satellites, communication equipment, traffic lights, lighthouses, wireless telephone booths, monitoring equipment in the field of oil drilling, power supply systems, camping lights, electric vehicles, electronic equipment chargers, building curtain walls, etc.

[0130] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0131] 1. Perovskite solar cells

[0132] Embodiment 1:

[0133] 1) Transparent electrode layer

[0134] The FTO glass was UV cleaned and used as a transparent electrode layer.

[0135] 2) Preparation of hole transport layer

[0136] A solution containing hole transport material PTAA is spin-coated on the transparent electrode layer and annealed to form a hole transport layer, wherein the spin-coating speed is 5000 rpm / s, the spin-coating time is 30 seconds, the annealing temperature is 100° C., the annealing time is 10 minutes, and the thickness of the hole transport layer is 15 nm.

[0137] 3) Preparation of perovskite layer

[0138] A solution containing raw materials of perovskite components is spin-coated on the hole transport layer and annealed to form a perovskite layer. The spin-coating speed is 5000 rpm / s, the spin-coating acceleration is 2000 rpm / s, the spin-coating time is 30 s, the annealing temperature is 100 ° C, the annealing time is 15 min, and the perovskite component is Cs 0.05 MA 0.1 FA 0.85 PbI3, the thickness of the perovskite layer is 600nm.

[0139] 4) Preparation of electron transport layer

[0140] The organic electron transport material PCBM, the first additive polymethyl methacrylate, and the second additive tetrabutylammonium tetrafluoroborate are dispersed in a mixed solvent to form an electron transport layer solution. In the electron transport layer solution, the mixed solvent is 2-methylanisole and chloroform in a volume ratio of 1:1.

[0141] The electron transport layer solution is spin-coated on the perovskite layer, and the electron transport layer is formed after the solvent is removed. The spin coating speed is 2000rpm / s, and the spin coating time is 30s. The mass fraction of PCBM in the electron transport layer is 94%, the mass fraction of polymethyl methacrylate is 5%, and the mass fraction of the second additive tetrabutylammonium tetrafluoroborate is 1%. The thickness of the electron transport layer is 40nm.

[0142] 5) Preparation of metal electrodes

[0143] A metal Ag electrode was formed on the electron transport layer using a thermal evaporation process. The evaporation rate was The thickness of the metal Ag electrode is 110 nm.

[0144] Embodiment 2:

[0145] This embodiment is basically the same as the embodiment 1, except that the type of the first additive is different. In this embodiment, the first additive is methacrylic acid-methyl methacrylate copolymer.

[0146] Embodiment 3:

[0147] This embodiment is basically the same as the embodiment 1, except that the type of the first additive is different. In this embodiment, the first additive is poly-4-vinylpyridine.

[0148] Embodiment 4:

[0149] This embodiment is basically the same as the embodiment 1, except that the type of the first additive is different. In this embodiment, the first additive is 4-vinylpyridine-styrene copolymer.

[0150] Embodiment 5:

[0151] This embodiment is basically the same as the embodiment 1, except that the type of the second additive of the tertiary amine molecule is different. In this embodiment, the second additive is tris(dimethylaminoethyl)amine, CAS No.: 33527-91-2.

[0152] Embodiment 6:

[0153] This embodiment is basically the same as the embodiment 1, except that the type of the second additive of the tertiary amine molecule is different. In this embodiment, the second additive is 1,7-bis(dimethylamino)heptane, CAS No.: 29333-99-1.

[0154] Embodiment 7:

[0155] This embodiment is basically the same as the embodiment 1, except that the type of the second additive of the tertiary amine molecule is different. In this embodiment, the second additive is 9,9-bis[3-(dimethylamino)propyl]fluorene, CAS No.: 1821313-63-6.

[0156] Embodiment 8:

[0157] This embodiment is substantially the same as the embodiment 1, except that the type of the second additive is different. In this embodiment, the second additive is a quaternary ammonium salt additive shown in Formula I. Specifically, the second additive is hexamethonium iodide, CAS No.: 870-62-2.

[0158] Embodiment 9:

[0159] This embodiment is basically the same as the embodiment 1, except that the type of the second additive is different. In this embodiment, the second additive is a quaternary ammonium salt additive shown in Formula I. Specifically, the second additive is dodecyltrimethylammonium bromide, CAS No.: 1119-94-4.

[0160] Embodiment 10:

[0161] This embodiment is basically the same as embodiment 1, except that the type of the second additive is different. In this embodiment, the second additive is a mixture of a quaternary ammonium salt additive shown in formula I and a tertiary amine molecule additive shown in formula II. Specifically, the second additive is a mixture of tetrabutylammonium tetrafluoroborate (CAS number: 429-42-5) and tris(dimethylaminoethyl)amine; and the mass fraction of the quaternary ammonium salt additive in the electron transport layer is 1%, and the mass fraction of the tertiary amine molecule additive is 1%.

[0162] Embodiment 11:

[0163] This embodiment is basically the same as the embodiment 1, and the only difference is that the type of organic electron transport material is different. In this embodiment, the organic electron transport material is naphthalene diimide.

[0164] Embodiment 12:

[0165] This embodiment is basically the same as the embodiment 1, and the only difference is that the type of organic electron transport material is different. In this embodiment, the organic electron transport material is perylene diimide.

[0166] Embodiment 13:

[0167] This embodiment is basically the same as embodiment 1, except that the mass fractions of the organic electron transport material, the first additive, and the second additive in the electron transport layer are different. The mass fraction of PCBM in the electron transport layer of this embodiment is 98%, the mass fraction of polymethyl methacrylate is 1%, and the mass fraction of the second additive tetrabutylammonium tetrafluoroborate is 1%.

[0168] Embodiment 14:

[0169] This embodiment is basically the same as the embodiment 1, and the only difference is that the mixed solvent used in the solution for forming the electron transport layer is different. In this embodiment, the mixed solvent is a chlorobenzene solvent and a dichloromethane solvent in a volume ratio of 1:2.

[0170] Comparative Example 1:

[0171] The comparative example is substantially the same as Example 1, except that the first additive and the second additive are not used in the electron transport layer.

[0172] Comparative Example 2:

[0173] This comparative example is basically the same as Example 1, except that the type of polymer additive in the electron transport layer is different. In this comparative example, the polymer additive is polyethylene.

[0174] Comparative Example 3:

[0175] This comparative example is basically the same as Example 1, except that the type of the second additive in the electron transport layer is different. In this comparative example, the second additive is tris(3-aminopropyl)amine, CAS No.: 4963-47-7.

[0176] 2. Performance measurement of solar cells

[0177] 1) Photoelectric conversion efficiency test

[0178] At 25°C, the perovskite solar cell was placed under sunlight through a test fixture with a light power density of 100mW / cm 2 Specifically, the test fixture and Keithley 2400 digital source meter were connected by the four-wire method, the starting voltage was set to -0.2V, the cut-off voltage was set to 1.2V, the scanning speed was set to 200mV / s, and the forward / reverse scanning was performed to record the short-circuit current density (Jsc), open-circuit voltage (Voc) and fill factor (FF).

[0179] Then, the photoelectric conversion efficiency (PCE) of the perovskite solar cell is calculated using the following formula: PCE = Jsc × Voc × FF / optical power density × 100%.

[0180] 2) Light aging test

[0181] Specific test process: The perovskite solar cell is placed under sunlight at 85°C, with a light power density of 100mW / cm 2 ,The maximum power point voltage of the solar cell was dynamically monitored by nitrogen box packaging, and the time, power, current, and voltage were recorded. The perovskite solar cell was aged in nitrogen for 1000 h.

[0182] After the perovskite solar cell was taken out, the above-mentioned photoelectric conversion efficiency test was performed. Specifically, the test fixture and the Keithley 2400 digital source meter were connected by the four-wire method, the starting voltage was set to -0.2V, the cut-off voltage was set to 1.2V, the scanning speed was set to 200mV / s, and the forward and reverse scanning was performed to record the short-circuit current density (Jsc), open-circuit voltage (Voc) and fill factor (FF).

[0183] Then, the photoelectric conversion efficiency (PCE) of the perovskite solar cell after light aging is calculated and compared with the PCE of the perovskite solar cell before aging. The light aging test results reflect the stability of the perovskite solar cell. Under the same aging time, the closer the efficiency after aging is to the initial efficiency, the better the stability of the cell.

[0184] The parameters and performance data of the perovskite solar cells of the above embodiments and comparative examples are shown in Tables 1 and 2.

[0185] Table 1

[0186]

[0187]

[0188] Table 2

[0189]

[0190]

[0191] It can be seen from the above embodiments and comparative examples that: in the electron transport layer of the organic electron transport material in the battery of each embodiment of the present application, a specific polymer macromolecule containing lone pairs of electrons such as O and N is used as the first additive, and a specific quaternary ammonium salt of the compound conforming to the general formula I and a tertiary amine molecule of the compound conforming to the general formula II are used as the second additive, and the photoelectric conversion efficiency and stability of the perovskite solar cell are better than those of comparative examples 1 to 3.

[0192] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0193] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description and drawings can be used to interpret the content of the claims.

Claims

1. A perovskite solar cell, characterized in that: It includes a transparent electrode layer and a perovskite layer, an electron transport layer and a metal electrode which are sequentially arranged on the transparent electrode layer; The electron transport layer includes an organic electron transport material, a first additive and a second additive; The first additive comprises one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly-4-vinylpyridine; The second additive comprises one or more of the following compounds of formula I and formula II: Wherein, R1, R2, R3, R5 and R6 are independently selected from C1-C4 alkyl groups; n1 and n2 are independently integers of 1-6; m1 and m2 are independently integers of 1-4; R4 and R7 are independently C1-C5 alkyl groups, C1-C5 alkoxy groups, C1-C5 alkylthiol groups, aryl groups, halogen groups, carboxyl groups, cyano groups or do not exist; X is one or more of Cl, Br, I, BF4, PF6 and TFSI; Y1 and Y2 are independently selected from any one of C, N, O and S or do not exist.

2. The perovskite solar cell according to claim 1, characterized in that Based on the total mass of the electron transport layer, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

3. The perovskite solar cell according to claim 1, characterized in that The second additive includes the compound of formula I and the compound of formula II, and the mass ratio of the compound of formula I to the compound of formula II is (0.5-2):

1.

4. The perovskite solar cell according to claim 1, characterized in that: The compound of formula I includes one or more of tetrabutylammonium tetrafluoroborate, hexamethylammonium iodide, and dodecyltrimethylammonium bromide.

5. The perovskite solar cell according to claim 1, characterized in that: The compound of formula II includes one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The thickness of the electron transport layer is 25 nm to 45 nm.

7. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, perylene diimide and its derivatives.

8. The method for preparing a perovskite solar cell according to any one of claims 1 to 7, characterized in that: The following steps are involved: providing the transparent electrode layer; and forming the perovskite layer, the electron transport layer and the metal electrode in sequence on the transparent electrode layer; The solution for forming the electron transport layer includes a solvent and a solute dispersed in the solvent, and the solute includes the organic electron transport material, the first additive and the second additive.

9. The method for preparing a perovskite solar cell according to claim 8, characterized in that: The solvent includes a first organic solvent and a second organic solvent, the first organic solvent has a boiling point of 38°C to 70°C, and the second organic solvent has a boiling point of 110°C to 210°C.

10. The method for preparing a perovskite solar cell according to claim 9, characterized in that: The preparation method satisfies at least one of the following: (1) the first organic solvent comprises one or more of chloroform, dichloromethane and tetrahydrofuran; (2) The second organic solvent includes one or more of chlorobenzene, o-dichlorobenzene, toluene, o-xylene, anisole, 2-methylanisole, 2-chlorophenol and 1,2,3,4-tetralin.

11. The method for preparing a perovskite solar cell according to claim 9 or 10, characterized in that: Based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%.

12. The method for preparing a perovskite solar cell according to claim 8, characterized in that: Based on the total mass of the solution, the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

13. The method for preparing a perovskite solar cell according to any one of claims 8 to 10 or 12, characterized in that: Based on the total mass of the solute, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

14. A photovoltaic module comprising the perovskite solar cell according to any one of claims 1 to 7.

15. A photovoltaic system comprising the photovoltaic module according to claim 14.

16. An electrical device comprising the perovskite solar cell according to any one of claims 1 to 7.

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