Solar cell and preparation method therefor, photovoltaic module, and power consumption apparatus and power generation apparatus

Abstract

The present application provides a solar cell and a preparation method therefor, a photovoltaic module, and a power consumption apparatus and a power generation apparatus. The solar cell comprises a first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer, wherein the perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer, the first passivation layer comprises a first passivation material and a second passivation material, the second passivation layer contains one of the first passivation material and the second passivation material, the first passivation material comprises a heterocyclic compound, and the second passivation material is a passivation material having a composition different from that of the first passivation material and capable of chemically bonding with anions or cations of a perovskite material in the perovskite light-absorbing layer.

Description

Solar cells and their manufacturing methods, photovoltaic modules, electricity consumption and power generation devices

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 2025101856794, filed on February 19, 2025, entitled "Solar Cells and Methods for Preparing Themselves, Photovoltaic Modules, Electricity Consumption and Power Generation Devices", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a solar cell and its preparation method, a photovoltaic module, and an electricity consumption and power generation device. Background Technology

[0004] Solar cells are a new type of photovoltaic device that directly converts solar radiation energy into electrical energy using the photovoltaic effect. Taking perovskite solar cells as an example, they use perovskite material as the light-absorbing layer and have advantages such as low cost, high low-light efficiency, and wide application scenarios. They are an excellent choice for next-generation mass-produced photovoltaic cells, can alleviate the energy crisis, and are one of the key development directions for new energy sources. However, the photoelectric conversion efficiency of current solar cells in practical applications remains relatively low. Summary of the Invention

[0005] To achieve the above objectives, this application provides a solar cell, a method for its fabrication, a photovoltaic module, and an electricity-generating device. This solar cell exhibits improved photoelectric conversion efficiency.

[0006] A first aspect of this application provides a solar cell comprising a first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer. The perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer. The first passivation layer is located between the perovskite light-absorbing layer and the second electrode layer. The second passivation layer is located between the first passivation layer and the second electrode layer. The first passivation layer comprises a first passivation material and a second passivation material. The second passivation layer contains one of the first passivation material and the second passivation material. The first passivation material comprises a heterocyclic compound. The second passivation material is a passivation material with a composition different from the first passivation material and capable of chemically bonding with anions or cations of the perovskite material in the perovskite light-absorbing layer.

[0007] In the aforementioned solar cell, a passivation layer is used to passivate the surface of the perovskite light-absorbing layer. The first passivation layer contains both a first passivation material and a second passivation material. The heterocyclic atoms of the heterocyclic compound have lone pairs of electrons that can preferentially coordinate with the B-site metal of the perovskite light-absorbing layer for initial passivation. The second passivation layer can further enhance the passivation effect, especially for tiny defects that are difficult to be covered by heterocyclic compounds, thereby improving the open-circuit voltage and fill factor of the solar cell. The two layers work together to reduce non-radiative recombination at the interface, improve the defect passivation effect, and help improve the photoelectric conversion efficiency and stability of the solar cell.

[0008] In some embodiments, the heterocyclic atoms of the heterocyclic compound include one or more of N, O, S, P, B, and Si. These heterocyclic atoms, such as N, O, and S, have lone pairs of electrons that can preferentially coordinate with the B-site metal of the perovskite light-absorbing layer for initial passivation.

[0009] In some embodiments, one or more of the following conditions are met: (1) the heterocyclic compound includes an aromatic heterocyclic compound;

[0010] (2) The heterocycles in the heterocyclic compounds have 5 to 6 ring atoms.

[0011] Heterocyclic compounds are used to modify the interface of perovskite films, with multiple active sites corresponding to undercoordinated Pb sites on the surface or grain boundaries of the perovskite film. 2+ Sn 2+ Halogen vacancies (I) - ,Br - Strong chemical interactions between defects can repair surface and grain boundary defects in perovskite films.

[0012] In some embodiments, the heterocycles in the heterocyclic compounds include one or more of the following: thiadiazole ring, thiazolium ring, thiophene ring, oxadiazole ring, imidazole ring, and pyridine ring;

[0013] Optionally, the heterocyclic compound includes one or more of thiadiazole compounds, thiazolium compounds, thiophene compounds, oxadiazole compounds, imidazole compounds, and pyridine compounds.

[0014] Compounds with different heterocyclic structures exert different effects in perovskite solar cells through various mechanisms. Thiadiazole and thiazole rings passivate defects by coordinating with the perovskite surface; thiophene and imidazole rings enhance interfacial stability through π-π stacking and aromaticity; and oxadiazole and pyridine rings improve carrier transport efficiency through electron attraction and interfacial energy level optimization. These heterocyclic molecules enhance the performance and stability of perovskite solar cells through mechanisms such as defect passivation, interfacial modification, energy level modulation, and ion migration suppression.

[0015] In some embodiments, the heterocyclic compound further includes one or more substituents R located on the heterocycle, each R independently comprising one or more combinations of mercapto, amino, alkylthio, alkoxy, cyano, -SCN, -BF3, aryl containing 6 to 30 cyclic atoms, heteroaryl containing 5 to 30 cyclic atoms, carboxyl, alkyl, and halogen.

[0016] In this way, the heterocyclic atoms and substituents R of heterocyclic compounds can serve as passivation active sites, which can simultaneously passivate multiple defects on the perovskite surface, significantly reduce the carrier recombination centers caused by positive charge defects and the reverse built-in electric field caused by negative charge defects at the upper interface, improve the open-circuit voltage and fill factor of the device, and thus help improve the photoelectric conversion efficiency of solar cells.

[0017] In some embodiments, the heterocyclic compound includes one or more of 2-amino-5-mercapto-1,3,4-thiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 2,5-dimercaptothiadiazole, 3-(5-mercapto-1,3,4-oxadiazole)benzonitrile, (5-mercapto-1,3,4-thiadiazole-2-ylthio)acetic acid, thiophene-2,5-diacetic acid, and 5-methylthio-1,3,4-thiadiazole-2-thiol.

[0018] Thus, by selecting heterocyclic compounds with multiple active sites, multiple defects on the perovskite surface can be passivated simultaneously, significantly reducing carrier recombination centers caused by positive charge defects and reverse built-in electric fields caused by negative charge defects at the upper interface, thereby improving the open-circuit voltage and fill factor of the device and thus improving the photoelectric conversion efficiency of the solar cell.

[0019] In some embodiments, the second passivating material includes one or more of organic amines and their salts, inorganic metal halide salts, and ionic liquids;

[0020] Alternatively, the organic amine salt includes an organic amine halide salt. The organic amine halide salt can passivate X-site defects (e.g., iodine defects) in the perovskite light-absorbing layer through anions therein.

[0021] In some embodiments, the organic amine includes one or more of aliphatic organic amines, aromatic amines, and heterocyclic amines; optionally, the aliphatic organic amine has 1 to 10 carbon atoms.

[0022] Optionally, the aromatic structure of the aromatic amine includes one or more of the following: benzene ring, biphenyl, naphthalene, anthracene, phenanthrene, quinoline, indole, benzofuran, dinaphthalene, triphenylene and its derivatives;

[0023] Optionally, the heterocyclic structure of the heterocyclic amine includes one or more of the following: piperazine ring, pyridine ring, pyrimidine ring, pyrazine ring, quinoline ring, imidazole ring, and thiazole ring.

[0024] In some embodiments, the second passivating material includes one or more of ethylenediamine hydrochloride, ethylenediamine dihydrochloride, propylenediamine iodine, piperazine dihydrochloride, piperazine dihydroiodide, 2-phenylethylamine hydroiodide, and 2-(4-fluorophenyl)ethylamine hydroiodide.

[0025] In some embodiments, one or more of the following conditions are met:

[0026] (1) The total thickness of the first passivation layer and the second passivation layer is 0.5 nm to 10 nm;

[0027] (2) The thickness of the first passivation layer is 0.1 nm to 5 nm;

[0028] (3) The mass content of the heterocyclic compound in the first passivation layer is 30% to 98%, and can be selected as 50% to 98%.

[0029] In some embodiments, one or more of the following features are satisfied:

[0030] (1) The solar cell further includes a first charge transport layer, which is disposed between the second passivation layer and the second electrode; optionally, the first charge transport layer is an electron transport layer.

[0031] (2) The solar cell further includes a second charge transport layer, which is disposed between the first electrode and the perovskite light-absorbing layer; optionally, the second charge transport layer is a hole transport layer.

[0032] Thus, the first charge transport layer and / or the second charge transport layer help to extract and transport electrons and / or holes generated by the perovskite light-absorbing layer to the corresponding electrode layers, thereby improving the photoelectric conversion efficiency of the solar cell.

[0033] In some embodiments, the second passivation layer contains the second passivation material, and the first charge transport layer is an electron transport layer;

[0034] Optionally, the second passivation layer comprises one or more of organic amine salts, inorganic metal halide salts, and ionic liquids.

[0035] The second passivation layer comprises one or more iso-salt passivation materials selected from organic amine salts, inorganic metal halide salts, and ionic liquids. These salt passivation materials allow the second passivation layer to align in an ordered manner on the first passivation layer, forming a dipole state. This facilitates charge separation and transport, and the electric field of the interfacial dipole layer provides additional driving force, helping charge carriers overcome the potential barrier at the interface, thereby improving charge transport efficiency. Forming the first charge transport layer on the second passivation layer also helps improve the uniformity and density of the charge transport materials in the first charge transport layer. Further, the second passivation layer comprises one or more iso-salt passivation materials selected from organic amine salts, inorganic metal halide salts, and ionic liquids, while the first charge transport layer is an electron transport layer.

[0036] In some embodiments, the solar cell further includes a third passivation layer disposed between the perovskite light-absorbing layer and the first passivation layer, wherein the passivation material contained in the third passivation layer is different from the passivation material contained in the second passivation layer.

[0037] Optionally, the thickness of the third passivation layer is 0.1 nm to 4 nm;

[0038] Optionally, one of the third passivation layer and the second passivation layer contains the first passivation material, and the other contains the second passivation material.

[0039] In some embodiments, the first electrode layer is a transparent electrode.

[0040] A second aspect of this application provides a method for preparing a solar cell, comprising the following steps:

[0041] A first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer are formed in a stacked configuration.

[0042] The first passivation layer includes a first passivation material and a second passivation material. The second passivation layer contains one of the first passivation material and the second passivation material. The first passivation material includes a heterocyclic compound. The second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

[0043] A second aspect of this application provides a method for preparing a solar cell, comprising the following steps:

[0044] A perovskite light-absorbing layer is formed on the first electrode;

[0045] A first passivation solution containing a first passivation material is coated onto the perovskite light-absorbing layer, and then annealed to obtain a first passivation film.

[0046] A second passivation solution containing a second passivation material is coated onto the first passivation film, followed by annealing.

[0047] The first passivation material includes a heterocyclic compound, and the second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

[0048] A second aspect of this application provides a method for preparing a solar cell, comprising the following steps:

[0049] A perovskite light-absorbing layer is formed on the first electrode;

[0050] A second passivation solution containing a second passivation material is coated onto the perovskite light-absorbing layer, and then annealed to obtain a second passivation film.

[0051] A first passivation solution containing a first passivation material is coated onto the second passivation film, followed by annealing.

[0052] The first passivation material includes a heterocyclic compound, and the second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

[0053] In some embodiments, one or more of the following conditions are met:

[0054] (1) The concentration of the heterocyclic compound in the first passivation solution is 0.25 mg / mL to 0.75 mg / mL;

[0055] (2) The concentration of the second passivating material in the second passivation solution is 0.25 mg / mL to 1 mg / mL;

[0056] (3) The annealing temperature is 90℃~120℃ and the time is 1min~10min.

[0057] In a third aspect, this application provides a solar cell prepared using the method provided in the second aspect of this application.

[0058] In a fourth aspect, this application provides a photovoltaic module, including a solar cell according to the first aspect of this application or a solar cell prepared by the preparation method of the second aspect of this application.

[0059] In a fifth aspect of this application, an electrical device is provided, including a solar cell according to the first or third aspect of this application, a solar cell prepared by the preparation method of the second aspect of this application, or a photovoltaic module according to the fourth aspect of this application.

[0060] According to a sixth aspect of this application, a power generation device is provided, including a solar cell according to the first or third aspect of this application, a solar cell prepared by the preparation method of the second aspect of this application, or a photovoltaic module according to the fourth aspect of this application.

[0061] The electrical appliances and power generation devices of this application include the solar cells provided in this application, and therefore have at least the same advantages as the solar cells.

[0062] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0063] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0064] Figure 1 is a schematic diagram of a solar cell according to an embodiment of this application.

[0065] Explanation of reference numerals in the attached figures: 1. Solar cell; 11. Substrate; 12. First electrode layer; 13. Second charge transport layer; 14. Perovskite light-absorbing layer; 151. First passivation layer; 152. Second passivation layer; 16. First charge transport layer; 17. Second electrode layer. Detailed Implementation

[0066] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0067] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be combined arbitrarily, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this document; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, stating that a parameter is an integer ≥2 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 instance, stating that a parameter is an integer selected from "2-10" is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0068] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0069] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0070] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0071] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0072] In this application, unless otherwise stated, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0073] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0074] In this application, the term "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, such as "C1-C6 alkyl," refer to alkyl groups containing 1 to 6 carbon atoms, and each occurrence can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, or C6 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(CH3)CH 2CH3), 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(C H3)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(CH3)CH2CH3), 4- Methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)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). Understandably, "alkylene" refers to a subunit derived from "alkyl" by removing one hydrogen atom.

[0075] In this application, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic rings, at least one is an aromatic ring system. For example, "C6-C30 aryl" refers to an aryl group containing 6 to 30 carbon atoms, and each occurrence can be independently C6, C7, C8, C9, C10, C15, C20, C25, or C30 aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene, and their derivatives.

[0076] In this application, "aromatic amines" refers to compounds obtained by substituting an amino group onto an "aryl" group. Without limitation, one, two, or three "aryl" groups can be linked by one amino group, or one, two, or three amino groups can be linked by an alkyl chain onto an "aryl" group. Suitable examples include, but are not limited to, piperidine and piperazine.

[0077] In this application, "heterocyclic compound" refers to a cyclic compound whose cyclic atoms contain one or more heteroatoms. Heteroatoms refer to atoms other than carbon (C), such as nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), boron (B), and silicon (Si).

[0078] In this application, "heterocyclic amine" refers to a group obtained by substituting an amino group into a "heterocyclic aryl group", or a compound in which the ring atom of the heterocyclic aryl group contains a -N- structure and a hydrogen atom (H) or a hydrocarbon group (such as methyl, ethyl, etc.) is attached to the N atom. Suitable examples include, but are not limited to, piperazine.

[0079] In this application, "heteroaryl" refers to an aryl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, an O atom, an S atom, etc. For example, "C3 to C30 heteroaryl" refers to a heteroaryl group containing 3 to 30 carbon atoms, and each occurrence can be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl, C8 heteroaryl, C9 heteroaryl, C10 heteroaryl, C15 heteroaryl, C20 heteroaryl, C25 heteroaryl, and C30 heteroaryl. Suitable examples include, but are not limited to: furanyl, benzofuranyl, thiophenyl, benzothiophenyl, pyrroleyl, pyrazolyl, triazolyl, imidazoyl, oxazolyl, oxadiazolyl, thiazoyl, tetrazolyl, indolyl, carbazoyl, pyrroloimidazoyl, pyrrolopyrroleyl, thiophenolopyrroleyl, thiophenolothiophenyl, furanolopyrroleyl, furanolofuranyl, thiophenolofuranyl, benzoisooxazolyl, benzoisothiazoyl, benzoimidazoyl, pyridinyl, pyrazinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, o-diazanaphthyl, quinoxalinyl, phenanthridine, primidinyl, quinazolinyl, and quinazolinoneyl.

[0080] In this application, when no linking site is specified in the group, it means that any linkable site in the group is selected as the linking site.

[0081] In this application, "halogen" refers to F, Cl, Br, and I.

[0082] In this application, the term "layer" refers to any structure that is substantially layered. A layer can have a thickness that varies with the extent of its extension. Typically, a layer has a substantially constant thickness. As used herein, "thickness" refers to the average thickness of the layer.

[0083] Solar cells, also known as photovoltaic cells, are devices that directly convert light energy into electrical energy through the photoelectric effect or photochemical effect. Perovskite solar cells are solar cells that utilize perovskite material as the light-absorbing material. The photoelectric conversion principle of perovskite solar cells is as follows: Incident light (e.g., sunlight) enters the device and reaches the perovskite light-absorbing layer, where it is absorbed. Under the excitation of the incident light, the perovskite light-absorbing layer generates electron-hole pairs. Under the action of an electric field, the holes and electrons separate, with electrons transferring to one electrode and holes transferring to the other electrode. Subsequently, a circuit is formed through an external circuit, which can be used to drive a load.

[0084] Compared to other solar cells, perovskite solar cells employing a light-absorbing layer exhibit higher theoretical photoelectric conversion efficiency. However, the actual efficiency of perovskite solar cells in practical applications still falls below the theoretical Shockley-Queisser (SQ) limit, primarily due to losses from nonradiative recombination. The fragile Coulomb interactions and weak ionic bonds in halide perovskites lead to more fragile atomic recombination and deviations on the derived film surface. Lattice interference and periodic atomic perturbations at the surface alter electronic behavior and band structure, generating a significant number of nonradiative recombination centers. This behavior is more pronounced at the surface than in a larger portion of the film, significantly impacting the properties of perovskite materials and device performance. Furthermore, the photoelectric performance stability of perovskite solar cells also needs improvement.

[0085] One embodiment of this application provides a solar cell, including a first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer. The perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer. The first passivation layer is located between the perovskite light-absorbing layer and the second electrode layer. The second passivation layer is located between the first passivation layer and the second electrode layer. The first passivation layer includes a first passivation material and a second passivation material. The second passivation layer contains one of the first passivation material and the second passivation material. The first passivation material includes a heterocyclic compound. The second passivation material is a passivation material with a different composition than the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

[0086] In this application, "chemical bonding" refers to the attraction between two atoms or ions located in a molecule, where one atom or ion is located in an independent molecule or crystal structure, or is an isolated atom or ion. This attraction (including atom-to-atom interactions, atom-to-ion interactions, and ion-to-ion interactions) can be a specific orbital interaction. In this application, "chemical bonding" is generally a non-covalent bond.

[0087] Anions in perovskite materials typically include X-site anions, such as halide ions or halide-like ions, and cations typically include A-site or B-site cations (chemical formula ABX3), or A-site, C-site, or D-site cations (chemical formula A2CDX6). At least some of the anions or cations in the perovskite material chemically bonded to the passivating material can be located on the surface of the perovskite material or at defect sites within the bulk of the perovskite crystal structure. Generally, the anions or cations in the perovskite material chemically bonded to the passivating material are located on the surface of the perovskite material and at grain boundaries within the bulk of the perovskite material.

[0088] In the aforementioned solar cell, a passivation layer is used to passivate the surface of the perovskite light-absorbing layer. The first passivation layer contains both a first passivation material and a second passivation material. The heterocyclic atoms of the heterocyclic compound have lone pairs of electrons that can preferentially coordinate with the B-site metal of the perovskite light-absorbing layer for initial passivation. The second passivation layer can further enhance the passivation effect, especially for tiny defects that are difficult to be covered by heterocyclic compounds, thereby improving the open-circuit voltage and fill factor of the solar cell. The two layers work together to reduce non-radiative recombination at the interface, improve the defect passivation effect, and help improve the photoelectric conversion efficiency and stability of the solar cell.

[0089] Furthermore, the first passivation material and the second passivation material in the first passivation layer are dispersed in the same layer.

[0090] Understandably, if both the first passivation layer and the second passivation layer contain heterocyclic compounds, the types (structural formulas) of the heterocyclic compounds in both layers may be the same or different; optionally, they may be the same. Understandably, if both the first passivation layer and the second passivation layer contain a first passivating material, the types (structural formulas) of the first passivating material in both layers may be the same or different; optionally, they may be the same.

[0091] Understandably, the first passivation layer may include, in addition to the first passivation material and the second passivation material, other passivation materials, or may not include other passivation materials.

[0092] Understandably, the second passivation layer containing one of the first passivation material and the second passivation material means that the second passivation layer either contains the first passivation material or contains the second passivation material, but cannot contain both the first passivation material and the second passivation material at the same time.

[0093] Two-dimensional maps of the mixed elemental distribution can be obtained by using SEM-EDS (scanning electron microscopy combined with energy-dispersive X-ray spectroscopy) and EELS (electron energy loss spectroscopy) on the interface between the first passivation layer and the perovskite light-absorbing layer. Further analysis of the elemental distribution can be achieved by combining this with other techniques such as APT (atomic probe tomography) or SIMS (secondary ion mass spectrometry). Furthermore, liquid chromatography-mass spectrometry can be used to determine the type and content of the material in the first passivation layer by detecting the unique mass-to-charge ratio of different compound molecules.

[0094] The elemental distribution of the second passivation layer can be detected by using APT, SIMS, XPS combined with ion beam etching on the interface facing the second electrode. Furthermore, liquid chromatography-mass spectrometry can be used to determine the type and content of the material in the second passivation layer by detecting the unique mass-to-charge ratio of different compound molecules.

[0095] In some embodiments, the heterocyclic atoms of the heterocyclic compound include one or more of N, O, S, P, B, and Si, optionally including one or more of N, O, and S. These heterocyclic atoms, such as N, O, and S, have lone pairs of electrons that can preferentially coordinate with the B-site metal of the perovskite light-absorbing layer for initial passivation.

[0096] In some embodiments, the heterocyclic atoms of the heterocyclic compound include two or more of N, O, and S. The heterocyclic compound contains multiple heterocyclic atoms, providing multiple passivation active sites and improving the passivation effect. As an example, the heterocyclic atoms include N and O, or the heterocyclic atoms include N and S. Further, the heterocyclic compound may have one or two N heterocyclic atoms.

[0097] In some embodiments, the heterocyclic compound includes an aromatic heterocyclic compound; further, the heterocycle in the heterocyclic compound has 5 to 6 ring atoms.

[0098] Furthermore, the heterocycles in the heterocyclic compounds include one or more of the following: thiadiazole ring, thiazolium ring, thiophene ring, oxadiazole ring, imidazole ring, and pyridine ring.

[0099] Optionally, the heterocyclic compound includes one or more of thiadiazole compounds, thiazolium compounds, thiophene compounds, oxadiazole compounds, imidazole compounds, and pyridine compounds.

[0100] Compounds with different heterocyclic structures exert different effects in perovskite solar cells through various mechanisms. Thiadiazole and thiazole rings passivate defects by coordinating with the perovskite surface; thiophene and imidazole rings enhance interfacial stability through π-π stacking and aromaticity; and oxadiazole and pyridine rings can improve carrier transport efficiency through electron attraction and interfacial energy level optimization. These heterocyclic molecules enhance the performance and stability of perovskite solar cells through mechanisms such as defect passivation, interfacial modification, energy level modulation, and ion migration suppression.

[0101] Specifically, the thiadiazole ring is a five-membered heterocycle containing two nitrogen atoms and one sulfur atom, exhibiting high chemical stability and aromaticity. Its electronic structure allows it to bind to defect sites on perovskite surfaces (such as Pb). 2+ The following compounds interact with perovskite: Thiophene ring sulfur atoms can form coordinate bonds with defect sites on the perovskite surface, and their π-π stacking properties enhance interfacial stability. Oxadiazole ring oxygen and nitrogen atoms can interact with defect sites on the perovskite surface, and their electron attraction promotes electron transport. Imidazole ring nitrogen atoms can coordinate with defect sites on the perovskite surface, and their basicity enhances interfacial stability. Pyridine ring nitrogen atoms can coordinate with defect sites on the perovskite surface, and their electron attraction promotes electron transport.

[0102] In some embodiments, the heterocyclic compound further includes one or more substituents R located on the heterocycle, each R independently comprising one or more combinations of mercapto, amino, alkylthio, alkoxy, cyano, -SCN, -BF3, aryl containing 6 to 30 cyclic atoms, heteroaryl containing 5 to 30 cyclic atoms, carboxyl, alkyl, and halogen. Thus, both the heterocyclic atoms and the substituents R of the heterocyclic compound can serve as passivation active sites, simultaneously passivating various defects on the perovskite surface. This significantly reduces carrier recombination centers caused by positive charge defects and the reverse built-in electric field caused by negative charge defects at the upper interface, improving the open-circuit voltage and fill factor of the device, thereby enhancing the photoelectric conversion efficiency of the solar cell.

[0103] Heterocyclic compounds are used to modify the interface of perovskite films, with multiple active sites corresponding to undercoordinated Pb sites on the surface or grain boundaries of the perovskite film. 2+ Sn 2+ Halogen vacancies (I) - ,Br - Strong chemical interactions between defects can repair surface and grain boundary defects in perovskite films.

[0104] Furthermore, in heterocyclic compounds, the substituent R is attached to a carbon atom of the heterocycle. Furthermore, in heterocyclic compounds, the number of substituent R is two or more, for example, two or three. Furthermore, in heterocyclic compounds, the multiple substituent R can be of the same or different types, and can be chosen to be different, thus providing different types of passivation active sites, which can simultaneously passivate multiple defects on the perovskite surface.

[0105] Furthermore, in the substituent R, the alkyl group can be a C1-C6 alkyl group. Furthermore, the alkyl group in the alkylthio group or alkoxy group can be a C1-C6 alkyl group. Furthermore, the substituent R contains one or more of an aryl group with 6-30 cyclic atoms and a heteroaryl group with 5-30 cyclic atoms.

[0106] As a non-limiting example, heterocyclic compounds include one or more of 2-amino-5-mercapto-1,3,4-thiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 2,5-dimercaptothiadiazole, 3-(5-mercapto-1,3,4-oxadiazole)benzonitrile, (5-mercapto-1,3,4-thiadiazole-2-ylthio)acetic acid, thiophene-2,5-diacetic acid, and 5-methylthio-1,3,4-thiadiazole-2-thiol.

[0107] The structural formulas of some heterocyclic compounds are as follows:

[0108] These heterocyclic compounds with multiple active sites can simultaneously passivate various defects on the perovskite surface, significantly reducing carrier recombination centers caused by positive charge defects and reverse built-in electric fields caused by negative charge defects at the upper interface, thereby improving the open-circuit voltage and fill factor of the device and thus helping to improve the photoelectric conversion efficiency of solar cells.

[0109] In some embodiments, the second passivating material includes one or more of organic amines and their salts, inorganic metal halide salts, and ionic liquids.

[0110] Furthermore, organic amine salts include organic amine halide salts. Organic amine halide salts can passivate X-site defects (e.g., iodine defects) in the perovskite light-absorbing layer through anions therein.

[0111] Furthermore, organic amine halide salts include one or more of aliphatic organic amine halide salts, aromatic amine halide salts, and heterocyclic amine halide salts.

[0112] Optionally, the number of carbon atoms in aliphatic organic amines and their halide salts is 1 to 10;

[0113] Optionally, the aromatic structure in the aromatic amine and its halide salt includes a benzene ring;

[0114] Optionally, the heterocyclic structure in the heterocyclic amine and its halide salt includes a piperazine ring.

[0115] As a non-limiting example, the second passivating material includes, but is not limited to, one or more of ethylenediamine hydrochloride, ethylenediamine dihydrochloride, propylenediamine iodine, piperazine dihydrochloride, piperazine dihydroiodide, 2-phenylethylamine hydroiodide, and 2-(4-fluorophenyl)ethylamine hydroiodide.

[0116] The structural formulas of some organic amine halide salts are as follows:

[0117] As a non-limiting example, inorganic metal halide salts include, but are not limited to, one or more of ammonium chloride (NH4Cl), ammonium iodide (NH4I), and ammonium bromide (NH4Br). Ammonium chloride can passivate iodide vacancies on the perovskite surface by providing chloride ions, thereby improving the crystallinity and surface defects of the perovskite film. Ammonium iodide can be used for passivation treatment of the perovskite surface by providing iodide ions to fill cation defects in the perovskite film. Ammonium bromide can adjust the band gap and crystallinity of the perovskite film by providing bromide ions.

[0118] As a non-limiting example, ionic liquids include, but are not limited to, one or more of 1-ethyl-3-methylimidazolium iodide and formamidinium acetate.

[0119] In some embodiments, the total thickness of the first passivation layer and the second passivation layer is 0.5 nm to 10 nm. In some examples, the total thickness of the first passivation layer and the second passivation layer is 0.5 nm to 5 nm. As an example, the total thickness of the first passivation layer and the second passivation layer can be 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of these values.

[0120] In some embodiments, the thickness of the first passivation layer is 0.1 nm to 5 nm. In some examples, the thickness of the first passivation layer is 0.1 nm, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of these values; it may be selected as 0.1 nm to 3 nm.

[0121] In some embodiments, the heterocyclic compound in the first passivation layer has a mass content of 30% to 98%. In some examples, the mass content of the heterocyclic compound in the first passivation layer is 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 92%, 95%, 98%, or any two of these values, and may be selected as 50% to 98% or 50% to 92%.

[0122] The structural composition and content of the components in the first passivation layer can be detected by one or more of the following methods: X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), and mass spectrometry (such as secondary ion mass spectrometry, SIMS).

[0123] In some embodiments, the solar cell further includes a third passivation layer disposed between the perovskite light-absorbing layer and the first passivation layer, wherein the passivation material contained in the third passivation layer is different from the passivation material contained in the second passivation layer.

[0124] Optionally, the thickness of the third passivation layer is 0.1 nm to 4 nm; in some examples, the thickness of the third passivation layer is 0.1 nm, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, or any two of these values.

[0125] Optionally, one of the third passivation layer and the second passivation layer contains the first passivation material, and the other contains the second passivation material.

[0126] In some embodiments, the solar cell further includes a first charge transport layer disposed between the second passivation layer and the second electrode.

[0127] In some embodiments, the second passivation layer contains a second passivation material, optionally comprising one or more isosal passivation materials selected from organic amine salts, inorganic metal halide salts, and ionic liquids. These salt passivation materials allow the second passivation layer to arrange itself in an ordered manner on the first passivation layer, forming a dipole state. This facilitates charge separation and transport, and the electric field of the interface dipole layer can provide additional driving force, helping charge carriers overcome the potential barrier at the interface, thereby improving charge transport efficiency. Furthermore, forming the first charge transport layer on the second passivation layer also helps improve the uniformity and density of the charge transport material in the first charge transport layer. Further, the second passivation layer comprises one or more isosal passivation materials selected from organic amine salts, inorganic metal halide salts, and ionic liquids, and the first charge transport layer is an electron transport layer.

[0128] In some embodiments, the solar cell further includes a second charge transport layer disposed between the first electrode and the perovskite light-absorbing layer. One of the first and second charge transport layers is an electron transport layer, and the other is a hole transport layer. The electron transport layer functions to transport electrons generated by the excitation of the perovskite light-absorbing layer to an adjacent electrode and blocks the transport of holes. The hole transport layer can extract and transport hole carriers and can block the passage of free electrons.

[0129] Furthermore, the first charge transport layer is an electron transport layer. Furthermore, the second charge transport layer is a hole transport layer.

[0130] The electron transport layer may include an electron transport material. This application does not specifically limit the electron transport material used in the electron transport layer; commonly used electron transport materials in the art can be used. For example, the electron transport material includes at least one of imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, semiconductor material oxides, titanates, fluorides and their derivatives, and materials obtained by doping or passivation. Exemplarily, the imide compound includes at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide, or maleimide. Exemplarily, the quinone compound includes at least one of benzoquinone, naphthoquinone, phenanthrenequinone, or anthraquinone. Exemplarily, the fullerene and its derivatives include fullerene C 60 Fullerene C 70 PCBM([6,6]-phenyl-C 61 methyl butyrate), [6,6]-phenyl C 71 Methyl butyrate (PC) 71At least one of the following: BM. Exemplarily, the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, and Cr; optionally, the metal oxide includes at least one of tin oxide (SnO2) and zinc oxide (ZnO). Exemplarily, the semiconductor material oxide includes silicon oxide. Exemplarily, the titanate includes at least one of strontium titanate and calcium titanate. Exemplarily, the fluoride includes at least one of lithium fluoride and calcium fluoride. Optionally, the electron transport layer includes fullerenes and their derivatives.

[0131] Without limitation, the hole transport layer may include, but is not limited to, one or more of the following hole transport materials and their derivatives: 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), methoxytriphenylamine-fluoroformamidinium, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid, poly3-hexylthiophene, and triterpenesene. The nucleus is triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobisfluorene, polythiophene, phosphate monomer, carbazole monomer, sulfonic acid monomer, triphenylamine monomer, aromatic monomer, metal oxide (which may be referred to as the first metal oxide), cuprous iodide, and cuprous thiocyanate, wherein the metal element in the first metal oxide may include one or more of Ni, Mo, W, and Cu, such as nickel oxide (NiO). x ), WO3.

[0132] In some embodiments, as shown in FIG1, the solar cell 1 includes a first electrode layer 12, a second charge transport layer 13, a perovskite light-absorbing layer 14, a first passivation layer 151, a second passivation layer 152, a first charge transport layer 16, and a second electrode layer 17 stacked together. The first charge transport layer 16 is an electron transport layer, and the second charge transport layer 13 is a hole transport layer.

[0133] In some embodiments, at least one of the first electrode layer and the second electrode layer is a transparent electrode for light incident. As shown in FIG1, in one example, the solar cell 1 further includes a substrate 11 for supporting the functional film layer of the solar cell 1. The first electrode layer 12 is disposed on the substrate 11; further, both the first electrode layer 12 and the substrate 11 are made of transparent material, and correspondingly, the solar cell is a reverse pin cell. Understandably, in other examples, the second electrode layer 17 may also be disposed on the substrate, and correspondingly, the solar cell is a conventional cell.

[0134] The transparent electrode can be a transparent conductive metal oxide electrode. Without limitation, the material of the transparent electrode can be, for example, one or more of the following: FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IWO (tungsten-doped indium oxide), lanthanide-doped indium oxide, antimony-doped tin oxide, etc. It is understood that the transparent electrode can use glass as a substrate, or it can use a transparent flexible substrate. Specifically, the material of the transparent flexible substrate can be, for example, an organic polymer material, which can be a mixture of one or more of the following materials in different proportions: polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), and polydimethylsiloxane (PDMS).

[0135] In some embodiments, the second electrode layer comprises a conductive material. Further, the conductive material can be an organic conductive material, an inorganic conductive material, or a combination thereof. Non-limiting examples of inorganic conductive materials include metallic conductive materials. Further, metallic conductive materials can include any one of gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), bismuth (Bi), platinum (Pt), magnesium (Mg), or any suitable mixture of the aforementioned elements. The conductive material can include a conductive oxide. Further, the conductive material can be a conductive oxide; non-limiting examples of conductive oxides can include one or more of FTO, ITO, IWO, AZO, etc.

[0136] In some embodiments, the perovskite light-absorbing layer has the chemical formula ABX3 or A2CDX6. Here, A ions are monovalent cations, B ions are divalent metal cations, C ions are monovalent metal cations, D ions are trivalent metal cations, and X ions are monovalent anions.

[0137] Optionally, A ion is a monovalent cation with a large radius, including one or more organic cations and metal cations. More preferably, the organic cation includes organic amine ions, formamidinyl (HC(NH2)2) ions, etc. + FA + One or more of the following: ) and imidazole groups; more preferably, the metal cation includes lithium ion (Li) + Sodium ions (Na) + ), potassium ions (K) + ), rubidium ions (Rb + ), cesium ions (Cs) + One or more of the following. Further, the organic amine ion includes methylamine (CH3NH3) + MA + ), dimethyl diammonium ion (MDA) 2+), phenylethylammonium ion (PEA) + ), oleyl ammonium ion (OA) + ( ), one or more of ethylamino, propylamino, butylamino, pentamino, and hexamino.

[0138] Optionally, the B ion includes Pb. 2+ (lead ions), Sn 2+ (tin ion), Be 2+ (beryllium ion), Mg 2+ (magnesium ions), Ca 2+ (calcium ions), Sr 2+ (strontium ion), Ba 2+ (Barium ions), Zn 2+ (zinc ions), Ge 2+ (germanium ions), Fe 2+ (ferrous ion), Mn 2+ Co 2+ (divalent cobalt ion), Cu 2+ (divalent copper ions) and Ni 2+ One or more of (divalent nickel ions); more preferably, B ions include Pb. 2+ (lead ions) and Sn 2+ One or two of (tin ions).

[0139] Optionally, the C ions include Cs + (cesium ion), Ag + (silver ions), K + (potassium ions) and Rb + One or more of (rubidium ions).

[0140] Optionally, the D ion includes Bi. 3+ (bismuth ion), Ni 3+ (trivalent nickel ion), Fe 3+ (ferric ions) and Cu 3+ One or more of (trivalent copper ions);

[0141] Optionally, the X ion includes one or more halogens or halogen-like ions, specifically including fluoride ions (F... - ), chloride ions (Cl) - ), bromide ions (Br) - ), iodide ions (I) - ), cyanate ions (CN) - ), thiocyanate ion (SCN) - One or more of the following; optionally, the X ion includes Cl... - ,Br - and I - One or more of them. Further, X includes I.- ,Br - One or two of them. X can be I. - ,Br - Or combinations thereof. In some embodiments, X is I. - .

[0142] It is understandable that the perovskite material in the aforementioned perovskite light-absorbing layer can be selected from Cs. x1 FA 1-x1 PbX3, Cs x1 MA 1-x1 PbX3, Cs m FA n MA 1-m-n PbX3, CsPbX3, MAPbX3, FAPbX3, Cs x1 FA 1-x1 Pb x2 Sn 1-x2 X3, Cs x1 FA 1-x1 Pb x2 Sn 1-x2 X3, Cs m FA n MA 1-m-n Pb x2 Sn 1-x2 X3, CsPb x2 Sn 1-x2 X3, MAPb x2 Sn 1-x2 X3 and FAPb x2 Sn 1-x2 One or more of X3, where 0 < x1 < 1, 0 < x2 < 1, 0 < m < 1, and 0 < n < 1.

[0143] As examples, perovskite materials include CH8I3N2Pb (FAPbI3) and Cs. 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3, CsPbBr3, CsPbI3, Cs 0.05 FA 0.95 PbI3 and MA 0.2 FA 0.8 One or more of PbI3.

[0144] Understandably, other film layers can be provided between the film layers of the aforementioned solar cell as needed. For example, optionally, a hole-blocking layer may be provided between the electrode layer and the electron transport layer of the aforementioned solar cell. The material of the hole-blocking layer may include, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and tin oxide. Alternatively, an electron-blocking layer may be provided between the electrode layer and the hole transport layer of the aforementioned solar cell.

[0145] In some embodiments, perovskite solar cells include single-junction cells and tandem cells. Tandem cells include double-junction cells, triple-junction cells, quadruple-junction cells, etc., which contain perovskite solar cells. Exemplary examples include perovskite-perovskite tandem cells and perovskite-crystalline silicon tandem cells.

[0146] One embodiment of this application provides a method for fabricating a solar cell, which can be used to fabricate the aforementioned solar cell. Furthermore, this application also provides a solar cell fabricated using this method. The fabrication method includes the following steps:

[0147] A first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer are formed in a stacked configuration.

[0148] The solar cells prepared by the above method have the same passivation layer as the solar cells described above, and therefore have at least the same advantages as the solar cells described above, which will not be repeated here. The detailed information about the passivation layer has been described in detail above, and will not be repeated here.

[0149] A multi-layer passivation layer can be formed by applying a first passivation solution and a second passivation solution in steps. Specifically, the passivation solution applied first forms a passivation film on the surface of the perovskite light-absorbing layer. The passivation solution applied later fills the gaps between the passivation molecules in the formed passivation film, making the passivation film a dense first passivation layer in which the first and second passivation materials are dispersed in the same layer. At the same time, the passivation solution applied later also forms a second passivation layer on the first passivation layer, thereby more effectively reducing the defect state density and improving the passivation effect.

[0150] Understandably, if the passivation solution applied first forms a thin passivation film on the surface of the perovskite light-absorbing layer, the passivation solution applied later can more fully fill the gaps between the passivation material molecules in the formed passivation film. This results in a dense first passivation layer where the first and second passivation materials are dispersed within the same layer. Simultaneously, the later-applied passivation solution also forms a second passivation layer on top of the first passivation layer. In this case, the passivation layer on the surface of the perovskite light-absorbing layer comprises a first passivation layer and a second passivation layer sequentially stacked on the surface of the perovskite light-absorbing layer.

[0151] Understandably, if the passivation solution applied first forms a thick passivation film on the surface of the perovskite light-absorbing layer, the passivation solution applied later can only fill the gaps between the passivation material molecules on the upper surface of the formed passivation film (the surface farthest from the perovskite light-absorbing layer), and it is not easy to fully fill the gaps between the passivation molecules in the lower layer of the formed passivation film. In this case, a third passivation layer is formed in the lower layer of the passivation film formed by the passivation solution applied first, and a dense first passivation layer is formed in the upper layer of the passivation film, in which the first and second passivation materials are dispersed in the same layer. At the same time, the passivation solution applied later also forms a second passivation layer on the first passivation layer. At this time, the passivation layer on the surface of the perovskite light-absorbing layer includes a third passivation layer, a first passivation layer, and a second passivation layer sequentially stacked on the surface of the perovskite light-absorbing layer.

[0152] Furthermore, compared to a single second passivation material, a single heterocyclic compound passivation layer, or a single-layer mixed passivation layer, this application employs a multi-layer passivation layer, which can more effectively reduce the defect state density and improve the passivation effect.

[0153] In the coating process, the passivation solution applied first can initially passivate the defect states on the perovskite surface, while the passivation solution applied later can further optimize the passivation effect, thereby reducing nonradiative recombination and improving the device's photoelectric conversion efficiency. Compared to the method of forming a mixed passivation layer by coating a mixed solution of heterocyclic compounds and salt passivation materials in one step, the step-by-step coating method can reduce the mutual interference between the two molecules of heterocyclic compounds and salt passivation materials in the mixed solution, more effectively reduce the defect state density and nonradiative recombination, and thus improve the device's photoelectric conversion efficiency.

[0154] Step-by-step coating allows for more precise adjustment of the work function and energy level positions of perovskite films, forming a gradient band structure more conducive to charge extraction. Furthermore, step-by-step spin coating effectively improves the surface morphology of perovskite films, making them smoother and more uniform, and reducing leakage current. Compared to one-step coating using a mixed solution of heterocyclic compounds and salt passivation materials, step-by-step coating eliminates the need to consider the matching of solubility and diffusion rates of the heterocyclic compounds and salt passivation materials in the mixed solution, simplifying the process and improving the uniformity of the coating morphology.

[0155] In some embodiments, the second passivation layer contains a second passivation material. In this case, the method for fabricating the solar cell includes the following steps S11 to S13:

[0156] Step S11: Form a perovskite light-absorbing layer on the first electrode.

[0157] Step S12: The first passivation solution containing the first passivation material is coated onto the perovskite light-absorbing layer, and the first passivation film is obtained by annealing.

[0158] Step S13: Apply the second passivation solution containing the second passivation material onto the first passivation film and anneal it.

[0159] Furthermore, by employing a step-by-step coating method, first applying a first passivation solution and then applying a second passivation solution, that is, first forming a passivation film containing heterocyclic compounds on the surface of the perovskite light-absorbing layer, and then coating the passivation film with a second passivation solution containing a second passivating material. The subsequently applied passivation solution can fill the gaps between the passivation molecules in the formed passivation film, making the passivation film form a dense, mixed first passivation layer. Simultaneously, the subsequently applied passivation solution also forms a second passivation layer on the first passivation layer, thereby more effectively reducing the defect state density and improving the passivation effect. At this point, the second passivation layer contains the second passivation material but not the first passivation material.

[0160] Furthermore, the second passivation material includes one or more isosal passivation materials such as organic amine salts, inorganic metal halide salts, and ionic liquids. Since salt passivation materials have better mobility than heterocyclic compounds, they are advantageous for filling the gaps between passivation molecules in the formed passivation film. The salt passivation materials in the second passivation material are orderly arranged on the first passivation layer to form a dipole state second passivation layer. This facilitates charge separation and transport. The electric field of the interfacial dipole layer can provide additional driving force, helping charge carriers overcome the potential barrier at the interface, thereby improving charge transport efficiency.

[0161] In some embodiments, the second passivation layer contains a first passivation material, which comprises a heterocyclic compound. In this case, the method for fabricating the solar cell includes the following steps S21 to S23:

[0162] Step S21: Form a perovskite light-absorbing layer on the first electrode.

[0163] Step S22: The second passivation solution containing the second passivation material is coated onto the perovskite light-absorbing layer, and then annealed to obtain the second passivation film.

[0164] Step S23: Apply the first passivation solution containing the first passivation material onto the second passivation film, and then perform annealing treatment.

[0165] Furthermore, by employing a step-by-step coating method, first coating the second passivation solution and then coating the first passivation solution, that is, first forming a passivation film containing the second passivation material on the surface of the perovskite light-absorbing layer, and then coating the passivation film with the first passivation solution containing the first passivation material. The subsequently coated passivation solution can fill the gaps between the passivation molecules in the formed passivation film, making the passivation film form a dense, mixed first passivation layer. Simultaneously, the subsequently coated passivation solution also forms a second passivation layer on the first passivation layer, thereby more effectively reducing the defect state density and improving the passivation effect. At this point, the second passivation layer contains the first passivation material but not the second passivation material.

[0166] Furthermore, the coating method includes, but is not limited to, any one of the following: spin coating, spray coating, blade coating, and slot coating.

[0167] Furthermore, the annealing temperature described above is all between 90℃ and 120℃. Furthermore, the annealing time described above is all between 1 min and 10 min. As an example, the annealing temperature can be 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, or any two of the above values. As an example, the annealing time can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any two of the above values.

[0168] Optionally, the concentration of the heterocyclic compound in the first passivation solution is 0.25 mg / mL to 0.75 mg / mL; as an example, it may be 0.25 mg / mL, 0.3 mg / mL, 0.35 mg / mL, 0.4 mg / mL, 0.45 mg / mL, 0.5 mg / mL, 0.55 mg / mL, 0.6 mg / mL, 0.65 mg / mL, 0.7 mg / mL, 0.75 mg / mL, or a range consisting of any two of the above values.

[0169] Optionally, the concentration of the salt passivating material in the second passivation solution is 0.25 mg / mL to 1 mg / mL; as an example, it can be 0.25 mg / mL, 0.3 mg / mL, 0.35 mg / mL, 0.4 mg / mL, 0.45 mg / mL, 0.5 mg / mL, 0.55 mg / mL, 0.6 mg / mL, 0.65 mg / mL, 0.7 mg / mL, 0.75 mg / mL, 0.8 mg / mL, 0.85 mg / mL, 0.9 mg / mL, 0.95 mg / mL, 1 mg / mL, or a range consisting of any two of the above values.

[0170] In some examples, the material of the perovskite light-absorbing layer includes a perovskite-type metal halide with the chemical formula ABX3. The preparation method of the perovskite light-absorbing layer includes the following steps: mixing material A, BX2 and solvent to obtain a perovskite precursor solution; then coating the perovskite precursor solution onto the corresponding substrate and annealing to obtain the perovskite light-absorbing layer.

[0171] The aforementioned first electrode layer, hole transport layer, electron transport layer, and second electrode layer can be prepared using methods commonly used in the art, including but not limited to solution methods and solid deposition methods. Solution methods include any one of spin coating, spraying, blade coating, and slot coating. Solid deposition methods include any one of vacuum evaporation, sputtering deposition, plasma deposition, ion deposition, and atomic layer deposition (ALD).

[0172] Other embodiments of this application provide a photovoltaic module, including the solar cell as described above.

[0173] The aforementioned solar cells have high light conversion efficiency and good stability, which can improve the efficiency of photovoltaic modules.

[0174] The aforementioned photovoltaic module includes one or more of the aforementioned solar cells, which can be selected according to specific application scenarios; further, the aforementioned photovoltaic module includes multiple of the aforementioned solar cells, which are connected in series or parallel to form a solar cell. Further, the aforementioned photovoltaic module may also include tandem cells. Tandem cells include, but are not limited to, crystalline silicon / perovskite tandem cells, all-perovskite tandem cells, and thin-film / perovskite tandem cells such as copper indium gallium selenide (CIGS).

[0175] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a backsheet.

[0176] The solar cell has an adhesive layer on each of its two surfaces. A backsheet is provided on the surface of one adhesive layer away from the solar cell, and a photovoltaic glass layer is provided on the surface of the other adhesive layer away from the solar cell.

[0177] The photovoltaic glass layer and backsheet are used to protect the solar cells, and they have the functions of sealing, insulation and waterproofing; the adhesive layer plays the role of bonding the photovoltaic glass layer to the solar cells and bonding the backsheet to the solar cells.

[0178] Optionally, the photovoltaic glass layer is made of tempered glass, the backsheet is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0179] Furthermore, the aforementioned photovoltaic modules also include junction boxes and outer frames.

[0180] Junction boxes are used to protect the entire photovoltaic module's power generation system. They are essentially a current transfer station. When a cell short-circuits, the junction box will automatically disconnect the short-circuited cell string.

[0181] The outer frame serves to support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0182] Furthermore, silicone is used to bond and seal the connections between the frame and other parts of the photovoltaic module. The photovoltaic module can convert solar energy into electrical energy, which can then be stored in batteries or used to power loads.

[0183] In some embodiments, the photovoltaic module is a solar panel.

[0184] According to one embodiment of this application, a photovoltaic system is also provided, including the photovoltaic module described above.

[0185] The photovoltaic system utilizes the photovoltaic effect of the solar cells in the aforementioned photovoltaic modules to directly convert solar radiation energy into electrical energy with high efficiency; furthermore, the aforementioned photovoltaic system is a photovoltaic power generation system.

[0186] Photovoltaic modules are the core component of a photovoltaic power generation system. The aforementioned photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios. Furthermore, when the aforementioned photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0187] The aforementioned photovoltaic system can be a stand-alone photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0188] An independent photovoltaic (PV) power generation system includes a PV array, battery bank, charge controller, power electronic converter (inverter), and load. Its working principle is that solar radiation energy is first converted into electrical energy by the PV array, then converted by the power electronic converter to supply power to the load. Simultaneously, excess electrical energy is stored as chemical energy in an energy storage device after passing through the charge controller. Thus, when sunlight is insufficient, the energy stored in the battery can be converted into 220V, 50Hz AC power by the power electronic inverter, filter, and power frequency transformer to supply AC loads.

[0189] A grid-connected photovoltaic (PV) 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 solar radiation energy is converted by the photovoltaic array, then converted into high-voltage DC by a high-frequency DC converter, and finally inverted by the power electronic inverter to output a sinusoidal alternating current to the grid that is in phase with the grid voltage.

[0190] The two photovoltaic power generation systems mentioned above each have their own characteristics and can be selected according to the specific application scenario.

[0191] Other embodiments of this application provide an electrical device, including a solar cell as described above or a photovoltaic module as described above.

[0192] Other embodiments of this application provide a power generation device, including a solar cell as described above or a photovoltaic module as described above.

[0193] In some embodiments, the perovskite solar cell described above can be a power generation device that functions as an electrical device. The type of power generation device may include, but is not limited to, integrated power generation. The location of the power generation device may include, but is not limited to, the roof of a vehicle, the back panel, etc.

[0194] Furthermore, the aforementioned electrical devices may include mobile devices, such as electric vehicles, electric trains, ships and satellites, power generation systems, etc., but are not limited to these.

[0195] As another implementation method, the power supply device can be a wearable device, such as a watch.

[0196] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0197] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0198] Example 1

[0199] A method for fabricating a solar cell device is as follows:

[0200] 1) Preparation of FTO conductive glass (including the first electrode layer of the substrate): FTO glass with a specification of 2.0*2.0cm2 was used to remove 0.35cm of FTO from both ends by laser etching, exposing the glass substrate; the etched FTO conductive glass was ultrasonically cleaned several times with water, acetone and isopropanol in sequence, and then dried with nitrogen gas for later use.

[0201] 2) Preparation of hole transport layer: FTO was treated with ultraviolet ozone. 100 μL of PEDOT:PSS aqueous solution (concentration 1.2 wt%) was dropped onto the FTO conductive glass substrate in step 1). The spin coating speed was 3000 rpm / s and the spin coating time was 30 s. After spin coating, the substrate was transferred to a hot stage at 150℃ and annealed for 20 min to obtain a hole transport layer with a thickness of 15 nm.

[0202] 3) Preparation of the perovskite light-absorbing layer: The perovskite light-absorbing layer was prepared using a one-step method. A perovskite precursor solution was spin-coated onto the prepared hole transport layer at 4000 rpm for 30 s. Approximately 10 s after the start of spin-coating, 400 μL of the anti-solvent chlorobenzene (CB) was added dropwise. The film was then placed on a hot plate and annealed at 110 °C for 60 min to obtain a perovskite light-absorbing layer with a thickness of 800 nm. 0.7 MA 0.3 Pb 0.5 Sn 0.5 I3.

[0203] 4) Preparation of the first passivation layer and the second passivation layer:

[0204] 4.1 A solution of 0.25 mg / mL 2-amino-5-mercapto-1,3,4-thiadiazole molecule (heterocyclic compound, first passivation material) in isopropanol (passivation solution A) was spin-coated onto the perovskite light-absorbing layer at a speed of 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a thiadiazole compound passivation layer.

[0205] 4.2. A solution of 0.5 mg / mL ethylenediamine dihydrochloride molecules (second passivation material) in isopropanol (passivation solution B) was spin-coated onto the thiadiazole compound passivation layer at a speed of 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain the ethylenediamine dihydrochloride passivation layer.

[0206] 5) Fabrication of electron transport layer / hole blocking layer: The thin film with the perovskite light-absorbing layer is placed in an evaporator and the evaporation vacuum is adjusted to 5*10. -4 Below Pa, an electron transport layer C60 with a thickness of 30 nm is deposited by vapor deposition at a rate of 0.05 A / s; a hole blocking layer BCP with a thickness of 10 nm is deposited on the electron transport layer C60 by vapor deposition at a rate of 0.1 A / s.

[0207] 6) Fabrication of the metal counter electrode (second electrode layer): On the BCP layer of the device obtained in step 4), a copper (Cu) metal layer with a thickness of 80 nm is vapor-deposited (vaporation rate of 0.1 A / s) as the second electrode layer.

[0208] 7) Apply a layer of encapsulating adhesive around and on the surface of the perovskite solar cell device. The encapsulating adhesive is a colorless and transparent epoxy resin adhesive. Cover the glass backing plate layer on the encapsulating adhesive and press it together. Let it stand for 2 hours to cure the encapsulating adhesive.

[0209] The perovskite solar cell obtained through the above steps is labeled as cell 1.

[0210] Examples 2-7

[0211] The process is basically the same as in Example 1, except that the preparation steps of the passivation layer are different. Specifically, the type of passivation material A (heterocyclic compound) in the passivation solution is different, but the concentration is the same, as shown below.

[0212] Example 8

[0213] The process is basically the same as in Example 2, except that the preparation steps of the passivation layer are different. Specifically, the concentration of passivation material A (heterocyclic compound) in the passivation solution is different, as shown below.

[0214] Example 9

[0215] The process is basically the same as in Example 3, except that the preparation steps of the passivation layer are different. Specifically, the concentration of passivation material A (heterocyclic compound) in the passivation solution is different, as shown below.

[0216] Examples 10-11

[0217] The process is basically the same as in Example 6, except that the preparation steps of the passivation layer are different. Specifically, the concentration of passivation material A (heterocyclic compound) in passivation solution A is different, as shown below.

[0218] Examples 12-13

[0219] The process is basically the same as in Example 1, except that the preparation steps of the passivation layer are different. Specifically, the type of passivation material B (salt passivation material) in the passivation solution B is different, as shown below.

[0220] Example 14

[0221] The method is basically the same as in Example 12, except that the preparation steps of the passivation layer are different. Specifically, the concentration of passivation material B (salt passivation material) in passivation solution B is different, as shown below.

[0222] Example 15

[0223] The method is basically the same as in Example 13, except that the preparation steps of the passivation layer are different. Specifically, the concentration of passivation material B (salt passivation material) in passivation solution B is different, as shown below.

[0224] Example 16

[0225] The process is basically the same as in Example 1, except that the preparation steps for the passivation layer are different. The specific steps are as follows:

[0226] 4.1 A solution of 0.5 mg / mL ethylenediamine dihydrochloride (second passivation material) in isopropanol (passivation solution B) was spin-coated onto the perovskite light-absorbing layer at a speed of 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a passivation film.

[0227] 4.2. Spin-coat the passivation film obtained in step 4.1 with an isopropanol solution (passivation solution A) of 0.25 mg / mL 2-amino-5-mercapto-1,3,4-thiadiazole molecule (heterocyclic compound, first passivation material) at a speed of 4500 rpm for 30 s, and then anneal at 100 °C for 5 min.

[0228] Comparative Example 1

[0229] It is basically the same as Example 1, except that the passivation layer preparation step is omitted.

[0230] Comparative Example 2

[0231] The results are basically the same as in Example 1, except that the coating step of passivation solution A is omitted and the thickness of the second passivation layer is different, as shown in Table 1.

[0232] Comparative Example 3

[0233] The results are basically the same as in Example 7, except that the coating step of passivation solution B is omitted, and the thickness of the first passivation layer is different, as shown in Table 1.

[0234] Comparative Example 4

[0235] The method is basically the same as in Example 7, except that the preparation steps of the passivation layer are different. Specifically, a one-step coating method is used to coat a mixed passivation solution of passivation material A and passivation material B onto the surface of the perovskite light-absorbing layer. The mixed passivation solution is an isopropanol solution containing 0.25 mg / mL of thiophene-2,5-diacetic acid molecules and 0.5 mg / mL of ethylenediamine dihydrochloride molecules. The thickness of the obtained passivation layer is shown in Table 1.

[0236] The following are performance tests.

[0237] (i) Testing of the thickness of each passivation layer and the mass content of heterocyclic compounds in the first passivation layer.

[0238] Two-dimensional maps of the mixed elemental distribution can be obtained by using SEM-EDS (Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy) and EELS (Electron Energy Loss Spectroscopy) to analyze the interface between each passivation layer and the perovskite light-absorbing layer. Further analysis of the elemental distribution can be achieved by combining this with other techniques such as APT (Atomic Probe Tomography) or SIMS (Secondary Ion Mass Spectrometry). In addition, liquid chromatography-mass spectrometry can be used to determine the type of passivation layer material and the mass content of heterocyclic compounds in the first passivation layer by detecting the unique mass-to-charge ratio of different compound molecules.

[0239] The thickness of each passivation layer can be obtained by using TOF_SIMS to obtain the overall interface map of the passivation layer. At the same time, by combining SEM_EDS, the cross-section of each passivation layer can be known. Then, the thickness of each passivation layer can be obtained by measuring the thickness of each passivation layer.

[0240] (II) Photoelectric conversion efficiency performance test.

[0241] Under normal temperature and pressure, a standard light source with an AM1.5G solar light source was used to simulate sunlight, conforming to the national standard IEC61215. The light intensity was corrected using crystalline silicon solar cells to achieve a solar intensity. The current-voltage characteristic curve of the solar cells under the illumination of the light source was measured using a four-channel digital source meter (Keithley 2440). The open-circuit voltage Voc, short-circuit current density Jsc, fill factor FF, and energy conversion efficiency Eff of the solar cells were obtained.

[0242] Among them, the incident light power P in 100mW / cm 2 Eff (Efficiency) = P out / P in ; =V oc ×J sc ×FF / P in =V oc ×J sc ×[(V mpp ×J mpp ) / (V oc ×J sc )] / P in .

[0243] Among them, P in P out V mpp J mpp V oc J scFF represent: incident light power, operating output power of the battery under test, voltage at the maximum power point of the battery under test, current at the maximum power point of the battery under test, open circuit voltage, short circuit current, and fill factor, respectively.

[0244] The parameters and performance results of the solar cells in each embodiment and comparative example are shown in Tables 1 and 2 below.

[0245] Table 1

[0246] Table 2

[0247] As shown in the table above, Comparative Example 1 did not use a passivation layer, Comparative Example 2 used only ethylenediamine dihydrochloride for passivation, Comparative Example 3 used only thiophene-2,5-diacetic acid for passivation, and Comparative Example 4 formed a mixed passivation layer through a one-step mixed coating method. The photoelectric conversion efficiency of the solar cells fabricated by these examples was consistently low. In contrast, the embodiments of this application employ a step-by-step coating method to form double or triple passivation layers, thereby improving the photoelectric conversion efficiency of the resulting solar cells.

[0248] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0249] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A solar cell comprising a first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer, wherein the perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer, the first passivation layer is located between the perovskite light-absorbing layer and the second electrode layer, and the second passivation layer is located between the first passivation layer and the second electrode layer. The first passivation layer comprises a first passivation material and a second passivation material, and the second passivation layer contains one of the first passivation material and the second passivation material. The first passivation material comprises a heterocyclic compound, and the second passivation material is a passivation material whose composition is different from that of the first passivation material and which is capable of chemically bonding with anions or cations of the perovskite material in the perovskite light-absorbing layer.

2. The solar cell as claimed in claim 1, wherein, The heterocyclic atoms of the heterocyclic compounds include one or more of N, O, S, P, B, and Si.

3. The solar cell as described in claim 1 or 2, wherein, One or more of the following conditions must be met: (1) The heterocyclic compounds include aromatic heterocyclic compounds; (2) The heterocycles in the heterocyclic compounds have 5 to 6 ring atoms.

4. The solar cell according to any one of claims 1 to 3, wherein, The heterocyclic compounds include one or more of the following: thiadiazole ring, thiazolium ring, thiophene ring, oxadiazole ring, imidazole ring, and pyridine ring; Optionally, the heterocyclic compound includes one or more of thiadiazole compounds, thiazolium compounds, thiophene compounds, oxadiazole compounds, imidazole compounds, and pyridine compounds.

5. The solar cell according to any one of claims 1 to 4, wherein, The heterocyclic compound further includes one or more substituents R located on the heterocycle, each R independently including one or more combinations of mercapto, amino, alkylthio, alkoxy, cyano, -SCN, -BF3, aryl containing 6 to 30 cyclic atoms, heteroaryl containing 5 to 30 cyclic atoms, carboxyl, alkyl and halogen.

6. The solar cell according to any one of claims 1 to 5, wherein, The heterocyclic compounds include one or more of 2-amino-5-mercapto-1,3,4-thiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 2,5-dimercaptothiadiazole, 3-(5-mercapto-1,3,4-oxadiazole)benzonitrile, (5-mercapto-1,3,4-thiadiazole-2-ylthio)acetic acid, thiophene-2,5-diacetic acid, and 5-methylthio-1,3,4-thiadiazole-2-thiol.

7. The solar cell according to any one of claims 1 to 6, wherein, The second passivation material includes one or more of organic amines and their salts, inorganic metal halide salts, and ionic liquids; Alternatively, organic amine salts include organic amine halide salts.

8. The solar cell of claim 7, wherein, The organic amine includes one or more of aliphatic organic amines, aromatic amines, and heterocyclic amines; optionally, the aliphatic organic amine has 1 to 10 carbon atoms. Optionally, the aromatic structure of the aromatic amine includes one or more of the following: benzene ring, biphenyl, naphthalene, anthracene, phenanthrene, quinoline, indole, benzofuran, dinaphthalene, triphenylene and its derivatives; Optionally, the heterocyclic structure of the heterocyclic amine includes one or more of the following: piperazine ring, pyridine ring, pyrimidine ring, pyrazine ring, quinoline ring, imidazole ring, and thiazole ring.

9. The solar cell according to any one of claims 1 to 8, wherein, The second passivating material includes one or more of ethylenediamine hydrochloride, ethylenediamine dihydrochloride, propylenediamine iodine, piperazine dihydrochloride, piperazine dihydroiodide, 2-phenylethylamine hydroiodide, and 2-(4-fluorophenyl)ethylamine hydroiodide.

10. The solar cell according to any one of claims 1 to 9, wherein, One or more of the following conditions must be met: (1) The total thickness of the first passivation layer and the second passivation layer is 0.5 nm to 10 nm; (2) The thickness of the first passivation layer is 0.1 nm to 5 nm; (3) The mass content of the heterocyclic compound in the first passivation layer is 30% to 98%, and can be selected as 50% to 98%.

11. The solar cell according to any one of claims 1 to 10, wherein, It meets one or more of the following characteristics: (1) The solar cell further includes a first charge transport layer, which is disposed between the second passivation layer and the second electrode; optionally, the first charge transport layer is an electron transport layer. (2) The solar cell further includes a second charge transport layer, which is disposed between the first electrode and the perovskite light-absorbing layer; optionally, the second charge transport layer is a hole transport layer.

12. The solar cell of claim 11, wherein, The second passivation layer contains the second passivation material, and the first charge transport layer is an electron transport layer; Optionally, the second passivation layer comprises one or more of organic amine salts, inorganic metal halide salts, and ionic liquids.

13. The solar cell according to any one of claims 1 to 12, wherein, The solar cell further includes a third passivation layer, which is disposed between the perovskite light-absorbing layer and the first passivation layer. The passivation material contained in the third passivation layer is different from the passivation material contained in the second passivation layer. Optionally, the thickness of the third passivation layer is 0.1 nm to 4 nm; Optionally, one of the third passivation layer and the second passivation layer contains the first passivation material, and the other contains the second passivation material.

14. The solar cell according to any one of claims 1 to 13, wherein, The first electrode layer is a transparent electrode.

15. A method for preparing a solar cell, wherein, Includes the following steps: A first electrode layer, a perovskite light-absorbing layer, a first passivation layer, a second passivation layer, and a second electrode layer are formed in a stacked configuration. The first passivation layer includes a first passivation material and a second passivation material. The second passivation layer contains one of the first passivation material and the second passivation material. The first passivation material includes a heterocyclic compound. The second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

16. A method for preparing a solar cell, comprising the following steps: A perovskite light-absorbing layer is formed on the first electrode; A first passivation solution containing a first passivation material is coated onto the perovskite light-absorbing layer, and then annealed to obtain a first passivation film. A second passivation solution containing a second passivation material is coated onto the first passivation film, followed by annealing. in, The first passivation material includes a heterocyclic compound, and the second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

17. A method for preparing a solar cell, comprising the following steps: A perovskite light-absorbing layer is formed on the first electrode; A second passivation solution containing a second passivation material is coated onto the perovskite light-absorbing layer, and then annealed to obtain a second passivation film. A first passivation solution containing a first passivation material is coated onto the second passivation film, followed by annealing. in, The first passivation material includes a heterocyclic compound, and the second passivation material is a passivation material with a different composition from the first passivation material and capable of chemically bonding with the anions or cations of the perovskite material in the perovskite light-absorbing layer.

18. The preparation method according to claim 16 or 17, wherein, One or more of the following conditions must be met: (1) The concentration of the heterocyclic compound in the first passivation solution is 0.25 mg / mL to 0.75 mg / mL; (2) The concentration of the second passivating material in the second passivation solution is 0.25 mg / mL to 1 mg / mL; (3) The annealing temperature is 90℃~120℃ and the time is 1min~10min.

19. A solar cell, prepared by the method described in any one of claims 16 to 18.

20. A photovoltaic module comprising a solar cell according to any one of claims 1 to 14, 19 or a solar cell prepared by any one of claims 15 to 18.

21. An electrical device comprising a solar cell according to any one of claims 1 to 14, 19, a solar cell prepared by the preparation method according to any one of claims 15 to 18, or a photovoltaic module according to claim 20.

22. A power generation device, comprising a solar cell according to any one of claims 1 to 14, 19, a solar cell prepared by the preparation method according to any one of claims 15 to 18, or a photovoltaic module according to claim 20.

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