Solar cell, manufacturing method thereof, power utilization device and power generation device

Abstract

The invention provides a solar cell and a preparation method thereof, electric equipment and power generation equipment. The solar cell comprises a first conductive electrode, a passivation layer, a light absorption layer, an electron transport layer and a second conductive electrode which are sequentially stacked from bottom to top, wherein the passivation layer comprises a passivator shown in the formula I. The solar cell provided by the invention has excellent photoelectric conversion efficiency and stability.

Description

Technical Field

[0001] The present application relates to the technical field of solar cell devices, and in particular to a solar cell and a manufacturing method thereof, an electrical device and a power generation device. Background Art

[0002] With the large-scale development and utilization of non-renewable energy sources such as coal and oil, their storage capacity can no longer meet the development needs of various industries such as agriculture and industry. Therefore, recycled and renewable energy has gradually become an alternative to non-renewable energy sources to promote social and industrial development. Among them, solar cells are widely used due to their environmental friendliness and ability to output electricity when exposed to sunlight.

[0003] In solar cells, a layer of material needs to be coated separately as a hole transport layer. However, this preparation method is complex and takes a long time to prepare, which is not conducive to the commercial mass production of solar cells. In addition, the hole transport layer materials commonly used are expensive and have poor thermal stability. Long-term use will significantly reduce the performance of the battery. Developing a high-performance battery without a hole transport layer is an effective way to solve the above problems. However, compared with the full-structure (containing a hole transport layer) battery, it still has the problems of insufficient charge transfer capacity and too low opening voltage, which affects the photoelectric conversion efficiency of the battery. Therefore, there is an urgent need to provide a solar cell without a hole transport layer with good photoelectric conversion efficiency and stability. Summary of the Invention

[0004] The present application is made in view of the above-mentioned problems, and its object is to provide a solar cell without a hole transport layer, which has excellent photoelectric conversion efficiency and stability.

[0005] A first aspect of the present application provides a solar cell, comprising a passivation layer, wherein the passivation layer comprises a passivating agent represented by Formula I,

[0006]

[0007] wherein A is selected from S or P;

[0008] R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent;

[0009] R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group;

[0010] R5 is selected from an oxoacid group or an oxoacid salt group;

[0011] X- is a negative monovalent ion.

[0012] In any embodiment, the solar cell comprises a first conductive electrode, a passivation layer, a light-absorbing layer, an electron transport layer and a second conductive electrode, which are sequentially stacked from bottom to top.

[0013] The sulfonium ion or phosphonium ion in the passivation agent is connected to the oxygen-containing acid group or oxygen-containing acid salt group through R4, which is beneficial to the built-in electric field between the first conductive electrode and the light-absorbing layer of the solar cell, promotes the extraction and transport of holes, and can also passivate the defects on the surface of the perovskite light-absorbing layer, so that the solar cell has good photoelectric conversion efficiency and stability.

[0014] In any embodiment, the oxygen-containing acid group comprises one or more of a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a boronic acid group and a phosphinic acid group; and the oxygen-containing acid salt group comprises one or more of alkali metal salts of the sulfonic acid group, the phosphonic acid group, the carboxylic acid group, the boronic acid group and the phosphinic acid group.

[0015] In any embodiment, the alkali metal salt comprises one or more of sodium salt, potassium salt, rubidium salt and cesium salt.

[0016] In any embodiment, R5 is selected from a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a boronic acid group, a sodium phosphonate group and a cesium phosphonate group.

[0017] The oxygen-containing acid group or oxygen-containing acid salt group is beneficial to increase the dipole moment of the passivation agent molecule, form a built-in electric field between the light-absorbing layer and the first conductive electrode, promote the extraction and transport of holes, and improve the photoelectric conversion efficiency of the solar cell.

[0018] In any embodiment, R4 is selected from or a C2-C4 alkylene group,

[0019] The linking group helps to improve the interaction between the passivation agent and the light-absorbing layer, play the role of the passivation agent, improve the overall structural integrity of the perovskite material in the light-absorbing layer, reduce the non-radiative charge recombination at the interface of the light-absorbing layer, and improve the stability of the solar cell.

[0020] In any embodiment, R1, R2 and R3 are selected from hydrogen or methyl.

[0021] In any embodiment, X - is selected from a halide ion or a pseudohalide ion.

[0022] In any embodiment, the halide ion comprises one or more of F - , Cl-, Br - , and I-; and the pseudohalide comprises one or more of CN - , SCN-, BF4 - , and PF6 - .

[0023] In any embodiment, the passivation agent is selected from any one of the following compounds:

[0024]

[0025] The passivation agent has a strong molecular dipole moment, which can form a strong built-in electric field between the light-absorbing layer and the first conductive electrode, promoting the extraction and transport of holes, playing the role of a hole transport layer, and improving the photoelectric conversion efficiency of the solar cell. Meanwhile, the presence of sulfonium ions or phosphonium ions in the passivation agent is conducive to passivating defects in the perovskite material, improving the stability of the solar cell.

[0026] In any embodiment, the passivation layer has a thickness of 0.1 nm to 20 nm.

[0027] A suitable thickness of the passivation layer can effectively reduce the probability of recombination of electrons and holes before they are effectively separated, improve the hole transport efficiency, and reduce the degradation of the light-absorbing layer material, thereby improving the stability and photoelectric conversion efficiency of the solar cell.

[0028] In any embodiment, the absolute value of the energy difference between the valence band top of the light-absorbing layer and the work function of the first conductive electrode is not more than 0.5 eV. The smaller the energy difference between the valence band top of the light-absorbing layer and the work function of the first conductive electrode, the closer they are, which is more conducive to the efficiency of hole transport and extraction, reduces non-radiative recombination at the interface, and improves the stability and photoelectric conversion efficiency of the solar cell.

[0029] In any embodiment, the light-absorbing layer comprises a perovskite compound, and the perovskite compound comprises at least one of ABX3and / or A2CDX6, wherein A, B, C, and D are inorganic, organic, or organic-inorganic hybrid cations, A is a monovalent cation comprising at least one of Cs + , CH3NH 3+ , NH2CH=NH 2+ ; B is a divalent cation comprising at least one of Pb 2+ , Sn 2+ , which can be Pb 2+ or Sn 2+ ; C can be Ag + ; D can be at least one of Bi 3+ , Sb 3+ , In 3+ ; X is an inorganic, organic, or organic-inorganic hybrid anion, and X comprises at least one of Br - , I - ;

[0030] The first conductive electrode includes at least one of fluorine-doped tin oxide, indium tin oxide, aluminum-doped zinc oxide, boron-doped indium zinc oxide, and indium-doped zinc oxide.

[0031] In any embodiment, a blocking layer is provided between the electron transport layer and the second conductive electrode, and the blocking layer satisfies at least one of the following conditions:

[0032] (1) The bottom of the conduction band of the blocking layer is lower than the bottom of the conduction band of the light absorbing layer, or the top of the valence band of the blocking layer is higher than the top of the valence band of the light absorbing layer;

[0033] (2) The thickness of the barrier layer is 0.5 nm to 20 nm;

[0034] (3) The barrier layer includes one or more of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, SnO2, ZnO and cerium oxide.

[0035] When the blocking layer provided between the electron transport layer and the second conductive electrode meets the above conditions, it is beneficial for electrons to be transported from the light-absorbing layer to the second conductive electrode, and is beneficial for preventing the reverse diffusion of holes, reducing the non-radiative recombination of electrons and holes, and improving the photoelectric conversion efficiency of the solar cell.

[0036] In any embodiment, the first conductive electrode comprises a conductive substrate, and the second conductive electrode comprises a metal electrode.

[0037] A second aspect of the present application provides a method for preparing a solar cell, comprising:

[0038] providing a first conductive electrode;

[0039] preparing a passivation layer on one side of the first conductive electrode;

[0040] preparing a light absorbing layer on a side of the passivation layer away from the first conductive electrode;

[0041] preparing an electron transport layer on a side of the light absorbing layer away from the passivation layer;

[0042] preparing a second conductive electrode on a side of the electron transport layer away from the light absorbing layer;

[0043] Wherein, the passivation layer includes a passivating agent shown in Formula I,

[0044]

[0045] wherein A is selected from S or P;

[0046] R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent;

[0047] R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group; R5 is selected from an oxoacid group or an oxoacid salt group;

[0048] X - It is a negative monovalent anion.

[0049] The method reduces the preparation of the hole transport layer, shortens the process flow, and reduces the production cost of solar cells.

[0050] In any embodiment, the passivation layer is prepared by a method comprising the following steps:

[0051] The passivating agent represented by formula I is dissolved in water or an organic solvent to obtain a passivating material, and the passivating material is coated on one side of the first conductive electrode to obtain a passivating layer.

[0052] The preparation process is mature and controllable, which is beneficial to the stability of the production quality of solar cells.

[0053] In any embodiment, the concentration of the passivating agent in the passivating material is 0.0001 mmol / mL-0.1 mmol / mL, which is conducive to coating the passivating material into a passivation layer with an appropriate thickness.

[0054] In any embodiment, the passivation layer and the light absorbing layer are prepared by a method comprising the following steps:

[0055] A passivating agent represented by formula I is dissolved in a precursor solution of a light-absorbing layer active material to obtain an in-situ passivating material, and the in-situ passivating material is coated on one side of the first conductive electrode to obtain a passivating layer coated on one side of the first conductive electrode and a light-absorbing layer located on a side of the passivating layer away from the first conductive electrode.

[0056] The method is advantageous for preparing the light absorption layer and the passivation layer in one step through in-situ passivation, thereby reducing the process flow.

[0057] In any embodiment, the light absorption layer active material precursor solution includes halogenated lead, and in the in-situ passivation material, the molar ratio of the passivating agent represented by Formula I to the halogenated lead is 0.1%-10%.

[0058] Adding a passivating agent to the precursor solution of the active material in the light-absorbing layer can effectively reduce defects in the perovskite material, play an in-situ passivating role, and improve the stability of the solar cell. At the same time, the passivating agent helps promote the extraction and transmission of holes, acting as a hole transport layer and improving the photoelectric conversion efficiency of the solar cell.

[0059] The third aspect of the present application further provides an electrical device, which comprises the solar cell of the first aspect of the present application and the solar cell prepared by the preparation method of the second aspect.

[0060] The fourth aspect of the present application further provides a power generation device, which comprises the solar cell of the first aspect of the present application and the solar cell prepared by the preparation method of the second aspect.

[0061] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0063] Figure 1 It is a schematic structural diagram of a solar cell according to one embodiment of the present application.

[0064] Explanation of reference numerals: 1: solar cell; 10: first conductive electrode; 111: passivation layer; 112: light absorption layer; 113: electron transport layer; 12: second conductive electrode. DETAILED DESCRIPTION

[0065] Below, embodiments of the solar cell, power-consuming device, and power generation device of the present application are described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid unnecessary length in the following description and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0066] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0067] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0068] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0069] Unless otherwise specified, all steps of the present application may be performed sequentially, randomly, or optionally sequentially. For example, the method includes steps (a) and (b), indicating 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), indicating 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.

[0070] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0071] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: 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).

[0072] Perovskite solar cells have attracted widespread attention due to their excellent optoelectronic properties, such as adjustable band gap, high light absorption coefficient, long carrier lifetime and diffusion length, high defect tolerance, and low-cost low-temperature liquid phase preparation method. However, the efficiency and stability of perovskite solar cells remain an important issue for their commercial application.

[0073] In current solar cells, a separate layer of material must be applied to serve as a hole transport layer. However, this preparation method is complex and time-consuming, hindering the commercial mass production of solar cells. The commonly used hole transport layer material is poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT:PSS), which is not only expensive but also an acidic solution with poor thermal stability. Long-term use significantly reduces cell performance. Developing a high-performance cell without a hole transport layer is an effective approach to addressing these issues. This not only simplifies the perovskite cell fabrication process and reduces costs, but also avoids side reactions at the perovskite interface, facilitating long-term stable operation. In perovskite cells based on a hole transport layer-free structure, the perovskite exhibits energy band bending at the interface near the transparent electrode, preventing electrons from recombinating with holes in the transparent electrode. This can improve the photoelectric conversion efficiency to a certain extent. However, compared to cells with a full hole transport layer, they still suffer from insufficient charge transfer capacity and a low operating voltage, which compromises the cell's photoelectric conversion efficiency.

[0074] [Perovskite solar cells]

[0075] Based on this, Figure 1 As shown, the first aspect of the present application provides a solar cell 1, comprising a first conductive electrode 10, a passivation layer 111, a light absorbing layer 112, an electron transport layer 113 and a second conductive electrode 12 stacked sequentially from bottom to top, wherein the passivation layer comprises a passivating agent as shown in Formula I,

[0076]

[0077] wherein A is selected from S or P;

[0078] R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent;

[0079] R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group;

[0080] R5 is selected from an oxoacid group or an oxoacid salt group;

[0081] X- is a negative monovalent ion.

[0082] In this article, chemical bonds Indicates whether the key exists or not. When absent, the R3 group is absent.

[0083] As used herein, the term "C1-C4 alkyl" refers to a straight-chain or branched saturated hydrocarbon group containing 1 to 4 carbon atoms.

[0084] As used herein, the term "C6-C10 arylene group" refers to a group formed by removing two hydrogen atoms from an aromatic hydrocarbon consisting of 6 to 10 carbon atoms, which may be a single ring or a condensed ring.

[0085] As used herein, the term "heteroarylene" refers to a radical formed by removing two hydrogen atoms from an aromatic hydrocarbon having 5 to 12 atoms, which may be a single ring or a fused ring, and which contains at least one heteroatom. The heteroatom may be nitrogen, oxygen, or sulfur.

[0086] As used herein, the term "C1-C6 alkylene" refers to a straight or branched hydrocarbon group with carbon atoms ranging from 1 to 6. "Alkylene" indicates that the group is a bridging unit connecting two other atoms or groups, rather than a complete molecule.

[0087] As used herein, the term "oxyacid group" refers to an acidic group containing an oxygen atom that releases a proton (H+), exhibiting acidic properties. Oxyacid groups typically consist of a central atom (e.g., sulfur, phosphorus, carbon, boron, etc.) attached to one or more oxygen atoms, and sometimes also contain one or more hydroxyl (-OH) groups.

[0088] As used herein, the term "oxyacid salt group" refers to an oxyacid group that loses one or more protons (H+) to form an anion that then combines with a positive ion to form a salt.

[0089] Without being bound by any theory, the sulfonium ions or phosphonium ions contained in the passivator carry a positive charge and can interact with the negatively charged sites in the perovskite material, passivating the surface defects of the perovskite material and improving the photoelectric conversion efficiency of the solar cell. In addition, the sulfonium ions or phosphonium ions are highly stable and, compared to ammonium ions, are less likely to undergo deprotonation reactions that can cause degradation of the perovskite material, which is beneficial to improving the stability of the solar cell.

[0090] The oxygen-containing acid group at the end of the passivator can remove hydrogen ions to form negatively charged anions, and its head group contains a positively charged sulfonium ion or phosphonium ion, so that the entire passivator molecule can form a built-in electric field at the interface between the perovskite light-absorbing layer and the first conductive electrode (e.g., a conductive substrate). When the end of the passivator molecule is an oxygen-containing acid salt group, on the one hand, it can increase the binding ability of the end group with the metal oxide conductive electrode. On the other hand, the oxygen-containing acid salt group can remove alkali metal ions to form negatively charged anions, which is beneficial to increase the molecular dipole moment and form a built-in electric field at the interface (the direction of the built-in electric field is from positive charge to negative charge, that is, from the perovskite light-absorbing layer to the first conductive electrode), promoting the extraction and transmission of holes, and improving the photoelectric conversion efficiency of the solar cell. At the same time, the built-in electric field may also help reduce the defect density at the interface, improve the chemical and thermal stability of the material, and improve the stability of the solar cell.

[0091] The arylene and heteroarylene groups in the linking group R4 in the passivator have a strong conjugated effect, which enables the passivator to form a strong interaction with the light-absorbing layer, which is beneficial for the passivator to be firmly adsorbed on the surface of the light-absorbing layer. The C1-C6 alkylene group can increase the contact area between the passivator and the surface of the light-absorbing layer through its chain length and its flexibility, which is beneficial for the passivator to be evenly distributed on the surface of the light-absorbing layer, fully exert the role of the passivator, improve the overall structural integrity of the perovskite material in the light-absorbing layer, reduce the non-radiative charge recombination at the interface of the light-absorbing layer, and improve the photoelectric conversion efficiency and stability of the solar cell.

[0092] A passivation layer including the above-mentioned passivator is provided between the light-absorbing layer and the first conductive electrode. It can not only promote the transport and extraction of holes through the built-in electric field of the molecular dipole, thereby acting as a hole transport layer, but also passivate the defects on the surface of the perovskite light-absorbing layer, so that the solar cell has both excellent photoelectric conversion efficiency and stability.

[0093] In some embodiments, the oxyacid group comprises one or more of a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a boric acid group, and a phosphinic acid group.

[0094] As used herein, the term "sulfonic acid" refers to a -SO3H group.

[0095] As used herein, the term "phosphonate" refers to a -PO(OH)2 group.

[0096] As used herein, the term "carboxylic acid group" refers to a -COOH group.

[0097] As used herein, the term "boronic acid" refers to a -B(OH)2 group.

[0098] As used herein, the term "phosphinate" refers to a -PH(OH) group.

[0099] The oxygen-containing acid group can remove hydrogen ions to form negatively charged anions, and the head end group in the passivator molecule contains positively charged sulfonium ions and phosphonium ions, so the entire passivator molecule is charged, which can form a built-in electric field at the interface between the perovskite light-absorbing layer and the first conductive electrode, promote the extraction and transmission of holes, and help improve the photoelectric conversion efficiency of solar cells.

[0100] In some embodiments, the oxo acid salt group comprises one or more of an alkali metal salt of a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a boric acid group, and a phosphinic acid group.

[0101] In some embodiments, the alkali metal salt comprises one or more of a sodium salt, a potassium salt, a rubidium salt, and a cesium salt. In some embodiments, the alkali metal salt comprises a sodium salt or a cesium salt.

[0102] In some embodiments, R5 is selected from sulfonic acid, phosphonic acid, carboxylic acid, boric acid, sodium phosphonate, and cesium phosphonate.

[0103] As used herein, the term "sodium phosphonate group" refers to a -POOH(ONa) group.

[0104] As used herein, the term "cesium phosphonate" refers to a -POOH(OCs) group.

[0105] On the one hand, the oxygen-containing salt group can increase the binding ability of the terminal group with the first conductive electrode. On the other hand, the oxygen-containing salt group can remove alkali metal ions, and the negatively charged anions formed can increase the molecular dipole moment, forming a strong built-in electric field at the interface, promoting the extraction and transmission of holes, and helping to improve the photoelectric conversion efficiency of solar cells.

[0106] In some embodiments, the R4 is selected from one or more of phenylene, thienylene and C2-C4 alkylene.

[0107] As used herein, the term "C2-C4 alkylene" refers to a straight or branched chain hydrocarbon group having 2 to 4 carbon atoms.

[0108] In some embodiments, the R4 includes one or more of ethylene, propylene, isopropylene, n-butylene, sec-butylene, isobutylene, and tert-butylene.

[0109] In some embodiments, the R4 includes one or more of phenylene, thienylene, ethylene, propylene, and n-butylene.

[0110] In some embodiments, the R4 is selected from Or C2-C4 alkylene. In some embodiments, the R4 is selected from Ethylene, propylene, butylene.

[0111] The linking group facilitates a strong interaction between the passivator and the light-absorbing layer or increases the contact area between the passivator and the light-absorbing layer, fully maximizing the passivator's effect, improving the overall structural integrity of the perovskite material in the perovskite layer, reducing non-radiative charge recombination at the interface of the light-absorbing layer, and improving the stability of the solar cell. Furthermore, it is possible to enhance the hydrophobicity of the passivator by regulating the length of the linking group, thereby blocking the effects of air and moisture on the passivator and further improving the stability of the solar cell.

[0112] In some embodiments, when A is S, R1 and R2 are selected from one or more of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and isobutyl.

[0113] In some embodiments, when A is S, R1 and R2 are both selected from hydrogen. In some embodiments, when A is S, R1 and R2 are both selected from methyl.

[0114] In some embodiments, when A is P, R1, R2, and R3 are selected from one or more of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and isobutyl.

[0115] In some embodiments, when A is P, R1, R2, and R3 are all selected from hydrogen. In some embodiments, when A is P, R1, R2, and R3 are all selected from methyl.

[0116] In some embodiments, the passivating agent comprises a cation having any of the following structures,

[0117]

[0118] In some embodiments, the X - is selected from halogen ions or pseudohalogen ions.

[0119] As used herein, the term "pseudohalogen" refers to an atomic group consisting of two or more atoms of non-metallic elements, which has properties similar to those of halogens in a free state.

[0120] In some embodiments, the halide ion comprises F - 、Cl - Br - , I - One or more of .

[0121] In some embodiments, the pseudohalogen comprises CN - 、SCN - 、BF4 - PF6 - One or more of .

[0122] In some embodiments, the passivating agent is selected from any one of the following compounds:

[0123]

[0124]

[0125] The sulfonium or phosphonium ions contained in the passivator carry a positive charge and can interact with negatively charged sites in the perovskite material, passivating surface defects in the perovskite material and improving the photoelectric conversion efficiency of the solar cell. The oxygen-containing acid group at the end of the passivator can remove hydrogen ions to form negatively charged anions. Its head group contains a positively charged sulfonium or phosphonium ion, allowing the entire passivator molecule to form a built-in electric field at the interface between the perovskite light-absorbing layer and the first conductive electrode. When the end of the passivator molecule is an oxygen-containing acid salt group, on the one hand, it can increase the binding ability of the end group to the first conductive electrode. On the other hand, the oxygen-containing acid salt group can remove alkali metal ions to form negatively charged anions, increasing the molecular dipole moment, forming a strong built-in electric field at the interface, promoting the extraction and transmission of holes, and improving the photoelectric conversion efficiency and stability of the solar cell.

[0126] In some embodiments, the passivation layer 111 has a thickness of 0.1 nm to 20 nm.

[0127] In some embodiments, the thickness of the passivation layer 111 is 0.1 nm-15 nm, 0.1 nm-10 nm, 0.1 nm-5 nm, 0.5 nm-20 nm, 1.0 nm-20 nm, 1.5 nm-20 nm, or 2.0 nm-20 nm. In some embodiments, the thickness of the passivation layer 111 is 0.1 nm, 0.5 nm, 1.0 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, or 20 nm, or a range between any two of these values, or any value within any of the above ranges.

[0128] A passivation layer that is too thick will increase the length of the hole transmission path from the perovskite light-absorbing layer to the first conductive electrode, leading to an increase in series resistance. It will also hinder hole transmission, causing holes to recombine on the surface, affecting the battery's photoelectric conversion efficiency. If the passivation layer is too thin, it will not be able to completely passivate defects, causing degradation of the light-absorbing layer material. An appropriate passivation layer thickness can effectively prevent non-radiative recombination of holes on the surface, that is, reduce the probability of electrons and holes recombine before they are effectively separated, improve hole transmission efficiency, reduce degradation of the light-absorbing layer material, and improve battery stability and photoelectric conversion efficiency.

[0129] In some embodiments, the absolute value of the energy difference between the valence band top of the light absorbing layer and the work function of the first conductive electrode does not exceed 0.5 eV. In some embodiments, the absolute value of the energy difference between the valence band top of the light absorbing layer and the work function of the first conductive electrode does not exceed 0.4 eV, 0.3 eV, 0.2 eV, or 0.1 eV.

[0130] In this article, the term "valence band top" refers to the energy of the highest energy level in the valence band of the absorber material, and its value is given relative to the Fermi level. For example, if the Fermi level is set to 0 eV, the energy level of the valence band top is given relative to the Fermi level.

[0131] As used herein, the term "work function of a conductive electrode" refers to the minimum energy required for an electron to migrate from the surface of the conductive electrode to a vacuum. The work function is the energy difference between the Fermi level of the conductive electrode and the vacuum level. In some embodiments, when the first conductive electrode is a conductive substrate, the work function of the first conductive electrode is the minimum energy required for an electron to migrate from the surface of the conductive substrate to a vacuum.

[0132] Herein, the "conductive substrate" refers to an electrode having high electrical conductivity and high visible light transmittance.

[0133] The valence band top of the light-absorbing layer can be measured using methods known in the art, for example, ultraviolet photoelectron spectroscopy or X-ray photoelectron spectroscopy.

[0134] The work function of the conductive electrode can be tested by methods known in the art. For example, it can be measured by photoelectron spectroscopy or inverse optical emission spectroscopy.

[0135] In some embodiments, the valence band top of the light absorbing layer is -5.1 eV, and the work function of the first conductive electrode is -4.7 eV.

[0136] The smaller the energy difference between the valence band top of the light-absorbing layer and the work function of the first conductive electrode, the closer the two are, which is more conducive to the transmission of holes through tunneling, and can improve the extraction efficiency of holes at the interface and reduce non-radiative recombination at the interface, thereby improving the stability of the battery and the photoelectric conversion efficiency.

[0137] In some embodiments, the light absorbing layer 112 includes a perovskite compound.

[0138] In some embodiments, the perovskite compound crystal structure satisfies at least one of ABX3 and / or A2CDX6; wherein A, B, C, and D are all inorganic, organic, or organic-inorganic mixed cations, A is a monovalent cation, including Cs + 、CH3NH 3+ (methylamine ion or MA + ), NH2CH=NH2+ (Formamidinium ion or FA + ) at least one of; B is a divalent cation, including Pb 2+ 、Sn 2+ At least one of, optionally Pb 2+ or Sn 2+ ; C can be selected as Ag + ; D can be selected as Bi 3+ 、Sb 3+ 、In 3+ At least one of; X is an inorganic, organic or organic-inorganic mixed anion, X includes Br - , I - At least one of .

[0139] In some embodiments, the perovskite compound comprises MA 0.3 FA 0.7 Pb 0.5 Sn 0.5 I3.

[0140] In some embodiments, the perovskite compound has a band gap of 1.20 eV to 2.30 eV.

[0141] In some embodiments, the band gap of the perovskite compound can be 1.50eV-2.30eV, 1.70eV-2.30eV, 1.90eV-2.30eV, 2.0eV-2.30eV, 2.20eV-2.30eV. In some embodiments, the band gap of the perovskite compound is 1.20eV, 1.30eV, 1.40eV, 1.50eV, 1.60eV, 1.70eV, 1.80eV, 1.90eV, 2.00eV, 2.10eV, 2.20eV, 2.30eV, or a range between any two of the above values ​​or any value in any of the above ranges.

[0142] When the band gap of the perovskite light-absorbing layer is within the above range, the solar cell can absorb more photons within the spectral range, further improving the photoelectric conversion efficiency of the cell.

[0143] In some embodiments, the light absorbing layer 112 has a thickness of 200 nm to 1000 nm.

[0144] In some embodiments, the thickness of the light absorbing layer 112 can be selected from 300 nm to 1000 nm, 400 nm to 1000 nm, 500 nm to 1000 nm, 600 nm to 1000 nm, 700 nm to 1000 nm, 800 nm to 1000 nm, or 900 nm to 1000 nm. In some embodiments, the thickness of the light absorbing layer 112 is 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or 1000 nm, or a range between any two of these values, or any value within any of the above ranges.

[0145] When the thickness of the perovskite light-absorbing layer 112 is within a suitable range, the solar cell can not only absorb a wide range of the solar spectrum but also has excellent charge transfer performance.

[0146] In some embodiments, the electron transport layer 113 includes [6,6]-phenyl C 61 Methyl butyrate (PC 61 BM), [6,6]-phenyl C 71 Methyl butyrate (PC 71 BM), fullerene C 60 (C 60 ), Fullerene C 70 (C 70 ), tin dioxide (SnO2), zinc oxide (ZnO), perylene diimide (PDI) materials, naphthalene diimide (NDI) materials and at least one of the above derivatives and materials obtained by doping or passivation.

[0147] In some embodiments, the thickness of the electron transport layer 113 is 5 nm to 100 nm.

[0148] In some embodiments, the thickness of the electron transport layer 113 is 10 nm-100 nm, 20 nm-100 nm, 30 nm-100 nm, 40 nm-100 nm, 50 nm-100 nm, 60 nm-100 nm, 70 nm-100 nm, 80 nm-100 nm, or 90 nm-100 nm. In some embodiments, the thickness of the electron transport layer 113 is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm, or a range between any two of these values, or any value within any of the above ranges.

[0149] In some embodiments, the first conductive electrode 10 includes a conductive substrate, which includes FTO (fluorine-doped SnO2 transparent conductive glass, SnO2:F), ITO (indium tin oxide transparent conductive glass), AZO (Al-doped ZnO transparent conductive glass), BZO (B-doped ZnO transparent conductive glass) and / or IZO (indium zinc oxide transparent conductive glass).

[0150] In some embodiments, the thickness of the first conductive electrode 10 is 10 nm-1000 nm.

[0151] In some embodiments, the thickness of the first conductive electrode 10 is 50 nm-1000 nm, 100 nm-1000 nm, 150 nm-1000 nm, 200 nm-1000 nm, 400 nm-1000 nm, 600 nm-1000 nm, 800 nm-1000 nm, or 900 nm-1000 nm. In some embodiments, the thickness of the conductive substrate is 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, or 1000 nm, or a range between any two of these values, or any value within any of the above ranges.

[0152] In some embodiments, the second conductive electrode 12 is a metal electrode, and the metal electrode is an organic, inorganic, or organic-inorganic hybrid conductive material, including but not limited to Ag, Cu, C, Au, Al, ITO, AZO, BZO, and IZO.

[0153] In some embodiments, the second conductive electrode 12 has a thickness of 10 nm to 1000 nm.

[0154] In some embodiments, the thickness of the second conductive electrode 12 is 50 nm-1000 nm, 100 nm-1000 nm, 150 nm-1000 nm, 200 nm-1000 nm, 400 nm-1000 nm, 600 nm-1000 nm, 800 nm-1000 nm, or 900 nm-1000 nm. In some embodiments, the thickness of the second conductive electrode 12 is 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, or 1000 nm, or a range between any two of these values, or any value within any of the above ranges.

[0155] In some embodiments, a blocking layer is further present between the electron transport layer 113 and the second conductive electrode 12 .

[0156] In some embodiments, the bottom of the conduction band of the blocking layer is lower than the bottom of the conduction band of the light absorbing layer. In some embodiments, the top of the valence band of the blocking layer is higher than the top of the valence band of the light absorbing layer.

[0157] As used herein, the term "conduction band bottom" refers to the lowest energy state that an electron can occupy, which is the lowest energy level of the conduction band.

[0158] As used herein, the term "top of the valence band" refers to the highest energy state that an electron can occupy, which is the highest energy level of the conduction band.

[0159] The bottom of the barrier layer's conduction band is lower than that of the perovskite light-absorbing layer, which means that the barrier layer is conducive to the transmission of electrons. The top of the barrier layer's valence band is higher than that of the perovskite light-absorbing layer, which can effectively prevent the reverse diffusion of holes.

[0160] In some embodiments, the thickness of the barrier layer is 0.5 nm to 20 nm. In some embodiments, the thickness of the barrier layer is 1 nm to 20 nm, 2 nm to 20 nm, 4 nm to 20 nm, 5 nm to 15 nm, 8 nm to 20 nm, 12 nm to 20 nm, 16 nm to 20 nm, or 18 nm to 20 nm. In some embodiments, the thickness of the barrier layer is 0.5 nm, 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, or 20 nm, or a range between any two of these values, or any value within any of the aforementioned ranges.

[0161] In some embodiments, the barrier layer includes one or more of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, tin oxide (SnO 2 ), zinc oxide (ZnO), and cerium oxide.

[0162] In some embodiments, the first conductive electrode comprises a conductive substrate, and the second conductive electrode comprises a metal electrode. In some embodiments, the first conductive electrode is a metal electrode, and the second conductive electrode is a conductive substrate.

[0163] In some embodiments, the solar cell includes a conductive substrate, a passivation layer, a light absorbing layer, an electron transport layer, and a second conductive electrode stacked sequentially from bottom to top, and the passivation layer includes a passivator shown in Formula I.

[0164] A second aspect of the present application provides a method for preparing a solar cell, comprising:

[0165] providing a first conductive electrode;

[0166] preparing a passivation layer on one side of the first conductive electrode;

[0167] preparing a light absorbing layer on a side of the passivation layer away from the first conductive electrode;

[0168] preparing an electron transport layer on a side of the light absorbing layer away from the passivation layer;

[0169] preparing a second conductive electrode on a side of the electron transport layer away from the light absorbing layer;

[0170] Wherein, the passivation layer includes a passivating agent shown in Formula I,

[0171]

[0172] wherein A is selected from S or P;

[0173] R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent;

[0174] R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group;

[0175] R5 is selected from an oxoacid group or an oxoacid salt group;

[0176] X - It is a negative monovalent ion.

[0177] The method for preparing a solar cell reduces the preparation of a hole transport layer, shortens the process flow, and reduces the production cost of the solar cell.

[0178] In some embodiments, the passivation layer is prepared by a method comprising the following steps:

[0179] dissolving the passivation agent represented by Formula I in water or an organic solvent to obtain a passivation material, and coating the passivation material on one side of the first conductive electrode to obtain the passivation layer.

[0180] The process for preparing the passivation layer of the solar cell is mature and controllable, which is conducive to the stability of the production quality of the solar cell.

[0181] In some embodiments, the concentration of the passivation agent in the passivation layer is 0.0001 mmol / mL-0.1 mmol / mL.

[0182] In some embodiments, the concentration of the passivation agent in the passivation layer is 0.0001 mmol / mL-0.05 mmol / mL, 0.0001 mmol / mL-0.01 mmol / mL, 0.0001 mmol / mL-0.005 mmol / mL, 0.0001 mmol / mL-0.001 mmol / mL, 0.0001 mmol / mL-0.0005 mmol / mL, 0.001 mmol / mL-0.005 mmol / mL, 0.001 mmol / mL-0.01 mmol / mL, 0.001 mmol / mL-0.05 mmol / mL. In some embodiments, the concentration of the passivation agent in the passivation layer is 0.0001 mmol / mL, 0.0005 mmol / mL, 0.001 mmol / mL, 0.005 mmol / mL, 0.01 mmol / mL, 0.05 mmol / mL, 0.1 mmol / mL, or a range between any two of the above values or any value in the above range. The concentration of the passivation agent in the passivation layer is within a suitable range, which is conducive to the coating of the passivation material into a passivation layer with a suitable thickness.

[0183] In some embodiments, the passivation layer and the light-absorbing layer are prepared by a method comprising the following steps:

[0184] dissolving the passivation agent represented by Formula I in the active material precursor solution of the light-absorbing layer to obtain an in-situ passivation material, and coating the in-situ passivation material on one side of the first conductive electrode to obtain a passivation layer coated on one side of the first conductive electrode and a light-absorbing layer located on the side of the passivation layer away from the first conductive electrode.

[0185] This method facilitates the preparation of a light-absorbing layer and a passivation layer in a single step through in-situ passivation, thus reducing the process flow. Without being bound by any theory, intermolecular forces or chemical reactions may exist between the passivator represented by Formula I and the light-absorbing layer active material in the precursor solution, causing the passivator molecules and the light-absorbing layer active material to spontaneously form distinct layers, with the passivator molecules forming a passivation layer on the surface of the light-absorbing layer.

[0186] In some embodiments, the light absorbing layer active material precursor solution includes halogenated lead.

[0187] In some embodiments, in the in-situ passivation material, the molar ratio of the passivating agent represented by Formula I to the halogenated lead is 0.1%-10%.

[0188] In some embodiments, in the in-situ passivation material, the molar ratio of the passivating agent represented by Formula I to the lead halide is 0.1%-8%, 0.1%-6%, 0.1%-4%, 0.1%-2%, or 0.1%-1%. In some embodiments, in the in-situ passivation material, the molar ratio of the passivating agent represented by Formula I to the lead halide is 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, or a range between any two of these values ​​or any value within any of the above ranges.

[0189] The passivator compound is added to the precursor solution of the active material of the light-absorbing layer. The oxygen-containing acid groups or oxygen-containing salt groups in the passivator spontaneously combine with the defect sites of the perovskite through coordination and seal the defect sites, reducing non-radiative recombination centers, playing an in-situ passivation role, and improving the stability of the solar cell. At the same time, the oxygen-containing acid groups or oxygen-containing salt groups can form negatively charged anions, which form a built-in electric field at the interface between the perovskite light-absorbing layer and the first conductive electrode with the positively charged sulfonium ions or phosphonium ions, promoting the extraction and transmission of holes, and improving the photoelectric conversion efficiency of the solar cell.

[0190] A third aspect of the present application provides an electrical device, comprising a solar cell according to an embodiment of the present application or a solar cell prepared by a preparation method according to an embodiment of the present application.

[0191] A fourth aspect of the present application provides a power generation device, comprising a solar cell according to an embodiment of the present application or a solar cell prepared by a preparation method according to an embodiment of the present application.

[0192] In some embodiments, solar cells can be used as power generation devices for electrical devices. The types of power generation devices may include, but are not limited to, integrated power generation. The electrical devices may include, but are not limited to, mobile devices (e.g., mobile phones, tablets, laptops, calculators, watches, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), automobiles, electric trains, ships, satellites, power generation systems, and the like. The location of the power generation device may include, but is not limited to, the roof or back panel of an automobile.

[0193] Example

[0194] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0195] 1. Preparation of passivating agent

[0196] Preparation Example 1: Add 20 ml of anhydrous dichloromethane to a reaction vessel at room temperature (20°C-30°C), fill the reaction vessel with nitrogen to expel air, add 20 mmol of (3-bromopropyl)boric acid, stir and dissolve, heat the reaction solution to 40°C, introduce 1 mol (about 22 L) of hydrogen sulfide gas, and use sodium hydroxide aqueous solution to collect the tail gas generated during the reaction. Reflux and stir for 24 hours. After the reaction is completed, the solvent is removed by rotary evaporation to obtain a crude product, which is recrystallized using ethanol to obtain a white solid, which is then vacuum dried to obtain a passivating agent. The yield was 90%.

[0197] Preparation Examples 2-5: The preparation method of Preparation Examples 2-4 is basically the same as that of Preparation Example 1, and the preparation method of Preparation Example 5 is basically the same as that of Preparation Example 3. For specific differences, see Table 1.

[0198] Preparation Example 6: At room temperature (20°C-30°C), 0.99 g (15.9 mmol) of dimethyl sulfide and 10 mL of acetonitrile were first added to the reaction vessel, followed by 0.81 g (5.3 mmol) of 4-bromopropionic acid, and stirred. After the reaction was complete, the solid at the bottom of the reaction vessel was collected and repeatedly washed with ether to obtain a crude product. Recrystallization was performed using ethanol to obtain a white solid, which was then dried in vacuo to obtain a passivating agent.

[0199] Preparation Example 7: The preparation method of Preparation Example 7 is basically the same as that of Preparation Example 6. For specific differences, see Table 1.

[0200] Preparation Example 8: At room temperature, 20 ml of anhydrous dichloromethane was added to a flask, nitrogen was filled into the reaction vessel to expel air, and 50 mmol of trimethylphosphine and 20 mmol of (3-bromopropyl) phosphoric acid were added to the reaction vessel. The reaction solution was heated to 40°C and refluxed with stirring for 24 hours. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a crude product, which was recrystallized from ethanol to obtain a white solid, which was then dried in vacuo to obtain a passivating agent. The yield was 85%.

[0201] Preparation Examples 9-10: The preparation methods of Preparation Examples 9-10 are basically the same as those of Preparation Example 6. For specific differences, see Table 1.

[0202] Preparation Example 11: At room temperature, 6 g (3 mmol) of the passivating agent of formula II-6 was added to a reaction vessel and dissolved in 5 mL of ethanol. A 1 mol / L aqueous solution of NaOH was prepared, 10 mL of which was added to the above solution, stirred and dissolved, and then concentrated. The precipitated solid was filtered and repeatedly washed with ether to obtain a white solid, which was then dried in vacuo to obtain the passivating agent. The yield was 30%.

[0203] Preparation Example 12: The preparation method of Preparation Example 12 is basically the same as that of Preparation Example 11, and the specific different parameters are shown in Table 1.

[0204] Preparation Example 13: At room temperature, 8.41 g (0.05 mol) of 4-methylthiobenzoic acid (CAS: 13205-48-6) and 6.9 g (0.055 mol) of dimethyl sulfate were mixed and stirred. After the reaction was completed, 100 mL of deionized water and 50 mL of diethyl ether were added for extraction to obtain an aqueous solution of 4-sulfoniumbenzoic acid sulfate. The solvent was removed by rotary evaporation to obtain a crude product, which was then dried in vacuo to obtain a passivating agent.

[0205] Preparation Example 14:

[0206] The preparation method of Preparation Example 14 is basically the same as that of Preparation Example 13, and the specific different parameters are shown in Table 1.

[0207] Table 1

[0208]

[0209]

[0210] 2. Preparation and performance testing of solar cells

[0211] Example 1

[0212] Preparation of transparent conductive electrode (conductive substrate): Specifications: 2.0×2.0 cm 2 Fluorine-doped tin oxide transparent conductive glass (FTO conductive glass) was laser-etched to remove 0.35 cm of FTO conductive glass at each end, exposing the glass substrate. The etched FTO conductive glass was ultrasonically cleaned with water, acetone, and isopropyl alcohol, followed by nitrogen drying, and then used as a conductive substrate. The work function of the conductive substrate was -4.7 eV.

[0213] Preparation of passivation layer: The passivation agent (Formula II-1) was dissolved in methanol at a concentration of 1 mg / mL to obtain a passivation material, which was spin-coated on a conductive substrate at 3000 rpm and annealed at 100°C for 10 min to obtain a passivation layer with a thickness of 5 nm.

[0214] Preparation of perovskite light-absorbing layer: Weigh 1.19mmol formamidine iodine, 0.51mmol methylamine iodine, 0.85mmol lead iodide, 0.85mmol stannous iodide, and 0.085mol stannous fluoride, dissolve in 1mL of a mixed solution of DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) with a volume ratio of 2:1, stir for 2h, and filter with a 0.22μm organic filter membrane to obtain MA 0.3 FA 0.7 Pb 0.5 Sn 0.5 I3 solution, spin-coat MA on the passivation layer at 5000 rpm 0.3 FA 0.7 Pb 0.5 Sn 0.5 The I3 solution was added for 30 seconds. During the last 5 seconds, 400 μL of chlorobenzene was added dropwise to the center of the substrate. The substrate was annealed at 100°C for 40 minutes and cooled to room temperature to form an 800 nm thick perovskite light-absorbing layer with a valence band top of -5.1 eV.

[0215] Preparation of the electron transport layer: [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was spin-coated on the perovskite absorber at 1500 rpm, annealed at 100°C for 10 minutes, and then spin-coated with the barrier layer 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) at 5000 rpm. The thickness of the electron transport layer was 50 nm, and the thickness of the barrier layer was 10 nm.

[0216] Preparation of metal electrode: Place the film with electron transport layer into the evaporation apparatus and wait until the vacuum degree of evaporation reaches 5×10 -4 Pa, an 80 nm metal back electrode Ag was evaporated at a rate of 0.1 A / s to prepare a solar cell 1.

[0217] Examples 2-14

[0218] The preparation methods of Examples 2-14 are basically the same as those of Example 1, except that the type of passivating agent is adjusted in the passivation layer preparation step, as shown in Table 1.

[0219] Example 15

[0220] The preparation method of Example 15 is basically the same as that of Example 1, except that:

[0221] The preparation step of the passivation layer is not included; and the preparation method of the perovskite light-absorbing layer is changed to: weigh 1.19 mmol of formamidinium iodine, 0.51 mmol of methylamine iodine, 0.85 mmol of lead iodide, 0.85 mmol of stannous iodide, 0.085 mol of stannous fluoride, and 0.17 mmol of passivator compound 7, dissolve them in 1 mL of a mixed solution of DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) with a volume ratio of 2:1, stir for 2 hours, filter with a 0.22 μm organic filter membrane to obtain a perovskite precursor solution, spin-coat the perovskite precursor solution at 5000 rpm for 30 seconds, add 400 μL of chlorobenzene to the center of the substrate in the last 5 seconds, anneal at 100°C for 40 minutes, and cool to room temperature to obtain a perovskite light-absorbing layer with a thickness of 800 nm.

[0222] Examples 16-17

[0223] The preparation methods of Examples 16-17 are basically the same as those of Example 15, except that the type of passivating agent is adjusted during the preparation of the perovskite light absorbing layer, as shown in Table 2.

[0224] Comparative Example 1

[0225] The preparation method of Comparative Example 1 is substantially the same as that of Example 1, except that no passivation layer is prepared.

[0226] The solar cells prepared in Examples 1-17 and Comparative Example 1 were tested using the following method:

[0227] 1. Photoelectric conversion efficiency and stability test

[0228] A solar simulator (Guangyan Technology) was used to test according to the national standard IEC61215. A crystalline silicon solar cell was used to calibrate the light intensity to an intensity of one sun, AM1.5. The test cell was connected to a digital source meter, and its photoelectric conversion efficiency was measured under light. The test voltage range was -0.2V-1.2V, and the scan rate was 50mV / s. The maximum photoelectric conversion efficiency was the highest efficiency of the test cell after 1-10 days of natural aging. The photoelectric conversion efficiency on the 30th day was the photoelectric conversion efficiency of the test cell after 30 days of storage in nitrogen in the dark. The stability, i.e., the maximum photoelectric conversion efficiency retention rate, was the ratio of the photoelectric conversion efficiency on the 30th day to the maximum photoelectric conversion efficiency.

[0229] The test results of Examples 1-15 and Comparative Example 1 are shown in Table 2:

[0230] Table 2

[0231]

[0232] In Examples 1-17, the solar cell includes a conductive substrate, a passivation layer, a light absorbing layer, an electron transport layer and a metal electrode stacked in sequence from bottom to top, and the passivation layer includes a passivating agent shown in Formulas II-1 to II-14. Compared with the solar cell without a passivation layer in Comparative Example 1, it can be seen that the solar cell of Examples 1-17 has both good photoelectric conversion efficiency and stability.

[0233] In Examples 1-10, the passivating agents of the solar cells include oxyacid groups, namely, boric acid groups, sulfonic acid groups, carboxylic acid groups, and phosphonic acid groups, respectively, and the solar cells have both good photoelectric conversion efficiency and stability. In Examples 11-12, the passivating agents of the solar cells include oxyacid groups, namely, sodium phosphonate groups and cesium phosphonate groups, and the solar cells have both excellent maximum photoelectric conversion efficiency and stability. Comparing Examples 11-12 with Example 10, it can be seen that, compared with phosphonic acid groups, the passivating agents containing sodium phosphonate groups or cesium phosphonate groups can further improve the maximum photoelectric conversion efficiency of the solar cell.

[0234] In Examples 7, 9, and 10, the linking group in the solar cell passivator is a C2-C4 alkylene group, and the solar cell achieves both excellent photoelectric conversion efficiency and stability. Comparing Examples 7 and 10 with Example 9, it can be seen that a linking group of propylene or n-butylene can further improve the stability of the solar cell compared to an ethylene group.

[0235] In Examples 13-14, the connecting groups in the solar cell passivator are phenylene and thienylene, respectively. The solar cell has both excellent photoelectric conversion efficiency and stability, wherein the stability is significantly improved.

[0236] In Examples 15-17, the passivation layer and the light-absorbing layer of the solar cell are prepared by a one-step method, and the passivation agent molecules and the light-absorbing layer active material precursor solution are passivated in situ to achieve the preparation of the passivation layer and the light-absorbing layer in one step. Compared with the solar cell without a passivation layer in Comparative Example 1, it can be seen that the solar cells of Examples 15-17 have good photoelectric conversion efficiency and stability. Compared with Example 7 and Examples 11-12, it can be seen that the solar cell prepared by the one-step method and the solar cell prepared by the method including the passivation layer preparation step have basically equivalent photoelectric conversion efficiency and stability. It can be understood that the passivator provided in the present application is flexible to use and can be applied to solar cells by different methods.

[0237] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A solar cell, characterized in that: The solar cell includes a passivation layer, and the passivation layer includes a passivating agent shown in Formula I, wherein A is selected from S or P; R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent; R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group; R5 is selected from an oxoacid group or an oxoacid salt group; X - It is a negative monovalent ion.

2. The solar cell according to claim 1, wherein The oxygen-containing acid group includes one or more of a sulfonic acid group, a phosphonic acid group, a carboxylic acid group, a boric acid group and a phosphinic acid group; The oxygen-containing acid salt group includes one or more of alkali metal salts of sulfonic acid, phosphonic acid, carboxylic acid, boric acid and phosphinic acid.

3. The solar cell according to claim 2, wherein The alkali metal salt includes one or more of sodium salt, potassium salt, rubidium salt and cesium salt.

4. The solar cell according to any one of claims 1 to 3, characterized in that The R5 is selected from sulfonic acid group, phosphonic acid group, carboxylic acid group, boric acid group, sodium phosphonate group, and cesium phosphonate group.

5. The solar cell according to any one of claims 1 to 4, characterized in that R4 is selected from or C2-C4 alkylene.

6. The solar cell according to any one of claims 1 to 5, characterized in that R1, R2, and R3 are all selected from hydrogen or methyl.

7. The solar cell according to any one of claims 1 to 6, characterized in that X - is selected from halogen ions or pseudohalogen ions.

8. The solar cell according to claim 7, characterized in that The halogen ions include F - 、Cl - Br - , I - One or more of; The pseudo halogens include CN - 、SCN - 、BF4 - PF6 - One or more of .

9. The solar cell according to any one of claims 1 to 8, characterized in that The passivating agent is selected from any one of the following compounds:

10. The solar cell according to any one of claims 1 to 9, characterized in that The thickness of the passivation layer is 0.1 nm-20 nm.

11. The solar cell according to any one of claims 1 to 10, characterized in that The solar cell comprises a first conductive electrode, a passivation layer, a light absorption layer, an electron transport layer and a second conductive electrode which are sequentially stacked from bottom to top.

12. The solar cell according to claim 11, characterized in that The absolute value of the energy difference between the valence band top of the light absorption layer and the work function of the first conductive electrode does not exceed 0.5 eV.

13. The solar cell according to claim 11 or 12, characterized in that The light absorbing layer includes a perovskite compound, and the perovskite compound includes at least one of ABX3 and / or A2CDX6, wherein A, B, C, and D are all inorganic, organic, or organic-inorganic mixed cations, A is a monovalent cation, including Cs + 、CH3NH 3+ 、NH2CH=NH 2+ At least one of; B is a divalent cation, including Pb 2+ 、Sn 2+ At least one of, optionally Pb 2+ or Sn 2+ ; C can be selected as Ag + ; D can be selected as Bi 3+ 、Sb 3+ 、In 3+ At least one of; X is an inorganic, organic or organic-inorganic mixed anion, X includes Br - , I- at least one; The first conductive electrode includes at least one of fluorine-doped tin oxide, indium tin oxide, aluminum-doped zinc oxide, boron-doped indium zinc oxide, and indium-doped zinc oxide.

14. The solar cell according to any one of claims 11 to 13, characterized in that A blocking layer is provided between the electron transport layer and the second conductive electrode, and the blocking layer satisfies at least one of the following conditions: (1) The conduction band bottom of the blocking layer is lower than the conduction band bottom of the light absorbing layer, or The valence band top of the blocking layer is higher than the valence band top of the light absorbing layer; (2) The thickness of the barrier layer is 0.5 nm to 20 nm; (3) The barrier layer includes one or more of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, SnO2, ZnO and cerium oxide.

15. The solar cell according to any one of claims 11 to 14, characterized in that The first conductive electrode includes a conductive substrate, and the second conductive electrode includes a metal electrode.

16. A method for manufacturing a solar cell, characterized in that: include: providing a first conductive electrode; preparing a passivation layer on one side of the first conductive electrode; preparing a light absorbing layer on a side of the passivation layer away from the first conductive electrode; preparing an electron transport layer on a side of the light absorbing layer away from the passivation layer; preparing a second conductive electrode on a side of the electron transport layer away from the light absorbing layer; Wherein, the passivation layer includes a passivating agent shown in Formula I, wherein A is selected from S or P; R1, R2, and R3 are each independently selected from hydrogen and C1-C4 alkyl; when A is P, R3 is present; when A is S, R3 is absent; R4 is selected from one or more of a C6-C10 arylene group, a C6-C10 heteroarylene group, and a C1-C6 alkylene group; R5 is selected from an oxoacid group or an oxoacid salt group; X- is a negative monovalent ion.

17. The preparation method according to claim 16, characterized in that The passivation layer is prepared by a method comprising the following steps: The passivating agent represented by formula I is dissolved in water or an organic solvent to obtain a passivating material, and the passivating material is coated on one side of the first conductive electrode to obtain a passivating layer.

18. The preparation method according to claim 16 or 17, characterized in that: The concentration of the passivating agent in the passivating material is 0.0001 mmol / mL-0.1 mmol / mL.

19. The preparation method according to any one of claims 16 to 18, characterized in that: The passivation layer and the light absorbing layer are prepared by a method comprising the following steps: A passivating agent represented by formula I is dissolved in a precursor solution of a light-absorbing layer active material to obtain an in-situ passivating material, and the in-situ passivating material is coated on one side of the first conductive electrode to obtain a passivating layer coated on one side of the first conductive electrode and a light-absorbing layer located on a side of the passivating layer away from the first conductive electrode.

20. The preparation method according to claim 19, characterized in that The light absorption layer active material precursor solution includes halogenated lead, and the molar ratio of the passivating agent shown in formula I to the halogenated lead is 0.1%-10%.

21. An electrical device, characterized in that: A solar cell comprising the solar cell according to any one of claims 1 to 15 or a solar cell prepared by the preparation method according to any one of claims 16 to 20.

22. A power generation device, characterized in that: A solar cell comprising the solar cell according to any one of claims 1 to 15 or a solar cell prepared by the preparation method according to any one of claims 16 to 20.

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