Perovskite solar cell, preparation method thereof, photovoltaic module, electric device and power generation device

Abstract

This application provides a perovskite solar cell and its fabrication method, photovoltaic module, electrical device, and power generation device. The perovskite solar cell includes a perovskite light-absorbing layer and a passivation layer disposed on one side of the perovskite light-absorbing layer. The passivation layer comprises a first passivation material and a second passivation material. The first passivation material contains fluorine and has an RP phase structure, while the second passivation material contains an ACI phase structure. The perovskite solar cell of this application exhibits excellent efficiency and stability.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a perovskite solar cell and its preparation method, photovoltaic module, power supply device and power generation device. Background Technology

[0002] Perovskite solar cells are electronic devices that can directly convert light energy into electrical energy. Their main working principle is the photovoltaic effect: when sunlight or other light sources shine on the semiconductor material of the photovoltaic device, the energy of photons is absorbed by the semiconductor, exciting electron-hole pairs. Under the influence of an electric field inside the semiconductor, electrons and holes move in different directions, creating a potential difference across the device. When an external circuit is connected, a current is generated.

[0003] However, the efficiency and stability of traditional perovskite solar cells are still relatively low, and how to improve the efficiency and stability of perovskite solar cells is one of the key issues that urgently need to be addressed. Summary of the Invention

[0004] To achieve the above objectives, the first aspect of this application provides a perovskite solar cell and a method for preparing the same, a photovoltaic module, an electrical device, and a power generation device, wherein the perovskite solar cell has improved efficiency and stability.

[0005] To achieve the above objectives, the first aspect of this application provides a perovskite solar cell, comprising:

[0006] Perovskite light-absorbing layer, and

[0007] A passivation layer is disposed on one side of the perovskite light-absorbing layer. The passivation layer comprises a first passivation material and a second passivation material. The first passivation material contains fluorine and has an RP phase structure, and the second passivation material contains an ACI phase structure.

[0008] The perovskite solar cell provided in this application includes a passivation layer. The first passivation material and the second passivation material in the passivation layer can work together to effectively reduce defects at the grain boundaries and in the bulk phase of the perovskite light-absorbing layer, suppress non-radiative recombination, and promote charge transfer at the interface of the perovskite light-absorbing layer, thereby effectively improving the efficiency and stability of the perovskite solar cell.

[0009] In some embodiments of this application, the first passivating material comprises materials satisfying the chemical formula (R)2A1. n- 1B1 n X1 3n+1 One or more of the compounds;

[0010] Where n≥1, R is R'-NH3 +R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated hydrocarbon groups, fluorinated aryl groups, and fluorinated arylalkyl groups;

[0011] A1 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, wherein the organic cation includes one or more of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion and imidazolyl ion;

[0012] B1 includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3 + Fe 3+ and Cu 3+ One or more of the following;

[0013] X1 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0014] Satisfying the chemical formula (R)2A1 n-1 B1 n X1 3n+1 The compound contains an RP phase structure, which can form a two-dimensional to three-dimensional heterojunction with the three-dimensional perovskite material in the perovskite light-absorbing layer. This can passivate defects and suppress non-radiative recombination at the interface, thus improving the efficiency and stability of perovskite solar cells.

[0015] In some embodiments of this application, in chemical formula (R)2A1n-1 B1 n X1 3n+1 In the compounds:

[0016] 1≤n≤20, R is R'-NH3 + R' is selected from one or more fluorinated C6-C10 aryl and fluorinated C7-C10 arylalkyl groups;

[0017] A1 includes methylamino ion, formamidinium ion, and Cs. + and Rb + One or more of the following;

[0018] B1 includes Pb 2+ and Sn 2+ One or two of them;

[0019] X1 includes I - Cl - ,Br - F - One or more of them.

[0020] This will facilitate further improvement in the efficiency and stability of perovskite solar cells.

[0021] In some embodiments of this application, the second passivating material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds;

[0022] Where m≥1, GA is C(NH2)3 + ;

[0023] A2 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, wherein the organic cation includes one or more of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion and imidazolyl ion;

[0024] B2 includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3 + Fe 3+ and Cu 3+ One or more of the following;

[0025] X2 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0026] Satisfying the chemical formula (GA)A2 m B2 m X2 3m+1 The compound contains an ACI phase structure, which not only exists at the interface of the perovskite light-absorbing layer, but also enters and is widely distributed in the bulk phase of the perovskite light-absorbing layer. The guanidine ions and A2 ions therein alternately occupy the interlayer space of the perovskite light-absorbing layer bulk phase, promoting the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity and enhancing the efficiency and stability of perovskite solar cells.

[0027] In some embodiments of this application, the second passivating material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds;

[0028] Where 1≤m≤10, GA is C(NH2)3 + ;

[0029] A2 includes methylamino ion, formamidinium ion, and Cs. + and Rb + One or more of the following;

[0030] B2 includes Pb 2+ and Sn 2+ One or two of them;

[0031] X2 includes I - Cl - ,Br - F - One or more of them.

[0032] This will facilitate further improvement in the efficiency and stability of perovskite solar cells.

[0033] In some embodiments of this application, the mass ratio of the first passivating material to the second passivating material is (0.2~0.8):(1~4). In other embodiments, the mass ratio of the first passivating material to the second passivating material is (0.1~0.4):1.

[0034] When the mass ratio of the first passivation material to the second passivation material is within the above range, it is beneficial to better leverage the synergistic effect between the first and second passivation materials. This effectively reduces defects at the grain boundaries and in the bulk phase of the perovskite light-absorbing layer, suppresses non-radiative recombination, and promotes charge transfer at the interface of the perovskite light-absorbing layer. Ultimately, this can effectively improve the efficiency and stability of perovskite solar cells.

[0035] In some embodiments of this application, one or more of the following conditions are met:

[0036] (1) The perovskite light-absorbing layer contains the second passivation material;

[0037] (2) The perovskite light-absorbing layer contains perovskite grains, and the average grain size of the perovskite grains is 590 nm to 1280 nm.

[0038] (3) The thickness of the passivation layer is 2nm~5nm.

[0039] The second passivation material containing the ACI phase structure enters the bulk phase of the perovskite light-absorbing layer, and the space cations in the ACI phase structure alternately occupy the interlayer space of the perovskite light-absorbing layer, which is conducive to promoting the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity.

[0040] In some embodiments of this application, the perovskite solar cell further includes:

[0041] First charge transport layer and / or second charge transport layer;

[0042] The first charge transport layer is disposed on the side of the perovskite light-absorbing layer away from the passivation layer, and / or the second charge transport layer is disposed on the side of the passivation layer away from the perovskite light-absorbing layer, wherein the first charge transport layer is one of an electron transport layer or a hole transport layer, and the second charge transport layer is the other of an electron transport layer or a hole transport layer.

[0043] By setting a first charge transport layer and / or a second charge transport layer, it is beneficial to extract and transport charge carriers (holes and / or electrons) generated by the perovskite light-absorbing layer, thereby improving the photoelectric conversion efficiency of perovskite solar cells.

[0044] In some embodiments of this application, the perovskite solar cell further includes a first electrode and a second electrode; the first electrode is disposed on the side of the perovskite light-absorbing layer opposite to the passivation layer, and the second electrode is disposed on the side of the passivation layer opposite to the perovskite light-absorbing layer.

[0045] The first and second electrodes are configured to collect electrons and holes generated by the perovskite light-absorbing layer, which are then used to extract the generated photocurrent.

[0046] A second aspect of this application provides a perovskite solar cell, comprising:

[0047] Perovskite light-absorbing layer, and

[0048] A passivation layer is disposed on one side of the perovskite light-absorbing layer. The raw materials for preparing the passivation layer include a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

[0049] The raw materials for preparing the passivation layer include a first passivation precursor material and a second passivation precursor material. During the preparation of the passivation layer, the first passivation precursor material and the second passivation precursor material will react with the interface of the perovskite light-absorbing layer or even some components in the bulk phase. At the same time, the first passivation precursor material and the second passivation precursor material may also interact with each other, thereby forming RP phase structure and ACI phase structure respectively, and thus forming the first passivation material, the second passivation material, and the passivation layer.

[0050] A third aspect of this application provides a method for fabricating a perovskite solar cell, comprising:

[0051] Formation of a perovskite light-absorbing layer;

[0052] A passivation precursor solution is coated on one side of the perovskite light-absorbing layer, and after annealing, a passivation layer is formed to prepare a perovskite solar cell.

[0053] The passivation precursor solution contains a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

[0054] When the passivation precursor solution is coated on one side of the perovskite light-absorbing layer and annealed, the first passivation precursor material and the second passivation precursor material will react with some components at the interface of the perovskite light-absorbing layer or even in the bulk phase. At the same time, the first passivation precursor material and the second passivation precursor material may also interact with each other, thereby forming RP phase structure and ACI phase structure respectively, and thus forming the first passivation material and the second passivation material, as well as the passivation layer. The RP phase structure and the ACI phase structure work together to reduce non-radiative recombination and interface defects, thereby improving device efficiency and stability.

[0055] In some embodiments of this application, one or more of the following conditions are met:

[0056] (1) The fluorine-substituted hydrocarbon ammonium salt includes one or more compounds that satisfy the chemical formula R'NH3Y1;

[0057] Wherein, R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated hydrocarbon groups, fluorinated aryl groups, and fluorinated arylalkyl groups, and Y1 includes I. - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of the following;

[0058] (2) The guanidine salt includes one or more compounds that satisfy the chemical formula GAY2, where GA is C(NH2)3. + Y2 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0059] When a compound satisfying the chemical formula R'NH3Y1 is coated on one side of a perovskite light-absorbing layer and annealed, it reacts with some components at the interface of the perovskite light-absorbing layer to generate a compound satisfying the chemical formula (R)2A1. n-1 B1 n X1 3n+1The first passivation material is formed during this process, and an RP phase structure is formed. R' enables the first passivation precursor material to be widely distributed throughout the entire interface of the perovskite light-absorbing layer, which is beneficial for improving its effect on the perovskite light-absorbing layer. When a compound satisfying the chemical formula GAY2 is coated on one side of the perovskite light-absorbing layer and annealed, it reacts with some components at the interface of the perovskite light-absorbing layer and in the bulk phase to generate a compound satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 The second passivating material is formed in the process, and an ACI phase structure is formed.

[0060] In some embodiments of this application, the mass ratio of the first passivation precursor material to the second passivation precursor material is (0.2~0.8):(1~4).

[0061] By controlling the mass ratio of the first passivation precursor material to the second passivation precursor material within a suitable range, it is not only beneficial to the formation of the RP phase structure and the ACI phase structure and their interaction, but also to improve the morphology of the perovskite light-absorbing layer, increase the average grain size of the perovskite grains in the perovskite light-absorbing layer and make the grain size distribution more uniform, make the surface of the perovskite light-absorbing layer more dense, and reduce the residue of the perovskite precursor liquid, thereby reducing the surface defects of the perovskite light-absorbing layer and improving the efficiency and stability of the perovskite solar cell.

[0062] The fourth aspect of this application provides a photovoltaic module, including the perovskite solar cell described in the first aspect of this application, the perovskite solar cell described in the second aspect of this application, and the perovskite solar cell prepared by the method described in the third aspect of this application.

[0063] The fifth aspect of this application provides an electrical device comprising one or more of the following: the perovskite solar cell described in the first aspect of this application, the perovskite solar cell described in the second aspect of this application, the perovskite solar cell prepared by the method described in the third aspect of this application, and the photovoltaic module of the fourth aspect of this application.

[0064] The sixth aspect of this application provides a power generation device, including one or more of the perovskite solar cell described in the first aspect of this application, the perovskite solar cell described in the second aspect of this application, the perovskite solar cell prepared by the method described in the third aspect of this application, and the photovoltaic module of the fourth aspect of this application.

[0065] The photovoltaic modules, electrical appliances, and power generation devices of this application include the perovskite solar cells provided in this application, and therefore have at least the same advantages as the perovskite solar cells.

[0066] 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

[0067] 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:

[0068] Figure 1 This is a schematic diagram of a perovskite solar cell according to one embodiment of this application.

[0069] Figure 2 The image shows the X-ray diffraction pattern of the passivation layer in Example 1.

[0070] Figure 3 The image shows the X-ray diffraction pattern of the passivation layer in Comparative Example 1.

[0071] Figure 4 This is a schematic diagram of an electrical device according to one embodiment of this application.

[0072] Figure reference numerals: 10 Perovskite light-absorbing layer; 11 Passivation layer; 12 First charge transport layer; 13 Second charge transport layer; 14 First electrode; 15 Second electrode; 16 Hole blocking layer. Detailed Implementation

[0073] 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.

[0074] 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.

[0075] 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.

[0076] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0077] 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.

[0078] 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.

[0079] In this application, open-ended technical features or solutions described using terms such as "containing," "including," or "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, if A includes a1, a2, and a3, it may also include other members or exclude additional members unless otherwise specified. This can be considered as providing both the feature or solution that "A consists of a1, a2, and a3" and the feature or solution that "A includes not only a1, a2, and a3, but also other members."

[0080] In this application, unless otherwise specified, 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.

[0081] 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.

[0082] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0083] The term "saturated alkyl" refers to a hydrocarbon group containing only a carbon-carbon single bond. Phrases containing this term, such as "C1-C8 saturated alkyl," refer to saturated alkyl groups containing 1 to 8 carbon atoms, and each occurrence can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, or C8 alkyl. Suitable examples include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, etc.

[0084] The term "unsaturated hydrocarbon group" refers to a hydrocarbon group containing a carbon-carbon double bond (i.e., alkenyl) or a carbon-carbon triple bond (i.e., alkynyl). Phrases containing this term, such as "C2-C9 unsaturated hydrocarbon group," refer to an alkenyl group containing 2-9 carbon atoms and / or an alkynyl group containing 2-9 carbon atoms, which, each time appearing, can independently be C2-alkenyl, C3-alkenyl, C4-alkenyl, C5-alkenyl, C6-alkenyl, C7-alkenyl, C8-alkenyl, or C9-alkenyl; and / or C2-alkynyl, C3-alkynyl, C4-alkynyl, C5-alkynyl, C6-alkynyl, C7-alkynyl, C8-alkynyl, or C9-alkynyl. Suitable examples include, but are not limited to: vinyl (-CH=CH2), allyl (-CH2CH=CH2), cyclopentenyl (-C5H7) and 5-hexenyl (-CH2CH2CH2CH2CH=CH2), ethynyl (-C≡CH) or propynyl (-CH2C≡CH), etc.

[0085] The term "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 compounds, at least one must be an aromatic ring system. For example, "C5-C20 aryl" refers to an aryl group containing 5 to 20 carbon atoms, and each occurrence can be independently C5, C6, C10, C14, C18, or C20 aryl. Suitable examples include, but are not limited to: phenyl, biphenyl, naphthyl, anthracene, phenanthrene, dinaphthylphenyl, triphenylene, and their derivatives.

[0086] The term "alkylaryl" refers to a hydrocarbon group derived by replacing at least one hydrogen atom bonded to a carbon atom on an alkyl group with an aryl group. The aryl moiety may include five or more carbon atoms, and the alkyl moiety may include one or more carbon atoms. Suitable examples include, but are not limited to, benzyl, 2-phenylethyl-1-yl, naphthylmethyl, 2-naphthylethyl-1-yl, naphthobenzyl, and 2-naphthophenylethyl-1-yl.

[0087] In perovskite solar cells, a passivation layer is often placed adjacent to the perovskite light-absorbing layer to passivate defects in the perovskite light-absorbing layer and suppress non-radiative recombination, thereby improving the efficiency and stability of the perovskite solar cell. However, current passivation layers have limited effect on improving the efficiency and stability of the cell, making it difficult to achieve effective improvements in efficiency and stability. To address this technical problem, this application proposes a perovskite solar cell with a passivation layer on one side of the perovskite light-absorbing layer. This passivation layer comprises a first passivation material and a second passivation material. Through the cooperation of the first and second passivation materials, the efficiency and stability of the perovskite solar cell can be effectively improved. The perovskite solar cell will be described in detail below.

[0088] Firstly, this application provides a perovskite solar cell, see [link to previous application]. Figure 1 It includes:

[0089] Perovskite light-absorbing layer 10, and

[0090] A passivation layer 11 is disposed on one side of the perovskite light-absorbing layer 10. The passivation layer 11 includes a first passivation material and a second passivation material. The first passivation material contains an RP phase structure and contains fluorine, and the second passivation material contains an ACI phase structure.

[0091] It should be noted that in this application, "RP (Ruddlesden-Popper) phase structure" is a two-dimensional layered perovskite structure, which includes perovskite layers and rock salt phase layers, and the perovskite layers and rock salt phase layers are stacked alternately, with space cations distributed between adjacent layers, and is cut into two-dimensional RP perovskites with (100) orientation along a specific (hkl) plane of the corresponding three-dimensional perovskite structure; "ACI (Alternating Cations in the Interlayer Space) phase structure" is an alternating cation phase structure in the interlayer space, which is a two-dimensional layered perovskite structure, which is composed of stacked perovskite layers, with space cations distributed between adjacent layers, and the space cations are arranged alternately by cations with relatively large radii and cations with relatively small radii.

[0092] Typically, the surface of a perovskite light-absorbing layer contains numerous negatively charged vacancy defects (such as vacancies caused by B-site cations (e.g., lead ions) and / or halide ions in the perovskite material). The first passivation material in the passivation layer is distributed at the interface of the perovskite light-absorbing layer and contains an RP phase structure and fluorine. The RP phase structure enables the first passivation material to form a two-dimensional to three-dimensional heterojunction with the three-dimensional perovskite material in the perovskite light-absorbing layer, which can passivate defects and suppress non-radiative recombination at the interface. Furthermore, the presence of fluorine can significantly increase the positive charge of the spatial cations in the RP phase structure, thereby significantly improving the adsorption of the first passivation material on the negatively charged surface of the perovskite light-absorbing layer. This achieves an effective interface passivation effect, effectively reduces the occurrence of non-radiative recombination at the interface, and improves the efficiency and stability of perovskite solar cells.

[0093] The second passivation material containing the ACI phase structure exists at the interface of the perovskite light-absorbing layer, which facilitates the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity. At the same time, the ACI phase structure distributed at the interface of the perovskite light-absorbing layer can also increase the size and crystallinity of the perovskite grains in the perovskite light-absorbing layer, further reducing the defect density at the interface and in the bulk phase of the perovskite light-absorbing layer. Thus, the improvement in conductivity and the reduction in defect density can further improve the efficiency and stability of perovskite solar cells.

[0094] Furthermore, the first passivation material and the second passivation material can work together to effectively reduce defects at the grain boundaries and in the bulk phase of the perovskite light-absorbing layer, suppress non-radiative recombination, and promote charge transfer at the interface of the perovskite light-absorbing layer, thereby effectively improving the efficiency and stability of perovskite solar cells.

[0095] As an example, the phase structure of the first and second perovskite materials can be tested using the following method: ToF-SIMS (Time of Flight Secondary Ion Mass Spectrometry) is used to detect the ion distribution in the passivation layer, thus detecting the presence of fluoride ions. Simultaneously, X-ray diffraction is used to test the passivation layer. By analyzing the diffraction characteristic peaks in the XRD pattern (such as analyzing the peak shape, position, and intensity differences), it can be determined whether the RP phase or ACI phase exists. The characteristic diffraction peak positions of the RP phase are 2θ = 4.455°~4.495°, and the characteristic diffraction peak positions of the ACI phase include: 2θ = 12.81°~12.97°, 2θ = 11.45°~11.56°, 2θ = 9.21°~9.40°, and optionally 2θ = 6.46°~6.50°.

[0096] In some embodiments, the perovskite light-absorbing layer includes a second passivation material. This second passivation material, containing an ACI phase structure, enters the bulk phase of the perovskite light-absorbing layer, and the space cations in the ACI phase structure alternately occupy the interlayer space of the perovskite light-absorbing layer bulk phase, facilitating the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity. Simultaneously, the second passivation material entering the bulk phase can also increase the size and crystallinity of the perovskite grains in the perovskite light-absorbing layer, further reducing the defect density at the perovskite light-absorbing layer interface and in the bulk phase. Therefore, the improved conductivity and reduced defect density can further enhance the efficiency and stability of the perovskite solar cell.

[0097] In some embodiments, the first passivating material comprises materials satisfying the chemical formula (R)₂A₁. n-1 B1 n X1 3n+1 One or more of the compounds; wherein n≥1, R is R'-NH3 + R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated hydrocarbon groups, fluorinated aryl groups, and fluorinated arylalkyl groups; A1 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, organic cations include methylamino ion (MA). + ), ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion (FA) + B1 includes one or more of the following: ) and imidazole ions; B1 includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3+ Fe 3+ and Cu 3+ One or more of them; X1 includes I - Cl - ,Br - F- CN - SeCN - SCN - and OCN - One or more of them.

[0098] Satisfying the chemical formula (R)2A1 n-1 B1 n X1 3n+1 The compound contains an RP phase structure, which can form a two-dimensional to three-dimensional heterojunction with the three-dimensional perovskite material in the perovskite absorbing layer. This can passivate defects and suppress nonradiative recombination at the interface. Furthermore, R' in R allows the first passivating material to be widely distributed throughout the entire interface of the perovskite absorbing layer, facilitating the improvement of the overall interface of the perovskite absorbing layer and achieving a better improvement effect. Simultaneously, fluorine substitution can significantly increase the NH3 content. + The positive charge at the end significantly enhances the adsorption of the compound on the negatively charged perovskite light-absorbing layer surface, thereby achieving a good interface passivation effect, effectively reducing the occurrence of non-radiative recombination at the interface, and improving the efficiency and stability of perovskite solar cells.

[0099] In some embodiments, the first passivating material comprises materials satisfying the chemical formula (R)₂A₁. n-1 B1 n X1 3n+1 One or more of the compounds; wherein 1 ≤ n ≤ 20, and R is R'-NH3 + R' is selected from one or more fluorinated C6-C10 aryl and fluorinated C7-C10 arylalkyl groups, and A1 includes MA. + FA + Cs + and Rb + One or more of them, B1 includes Pb 2+ and Sn 2+ One or two of them, X1 includes I - Cl - ,Br - F - One or more of these. This is beneficial for further improving the efficiency and stability of perovskite solar cells.

[0100] In some embodiments, the first passivation material includes ( )2Cs 0.05 FA 0.95 Pb2I7, ( )2Cs 0.05 FA 0.95 Pb2I7, ( )2Cs 0.05 FA 0.95Pb2I7, ( )2Cs 0.05 MA 0.95 Pb2I7, ( )2Cs 0.05 MA 0.95 Pb2I7, ( )2Cs 0.05 MA 0.95 Pb2I7, ( )2Rb 0.05 MA 0.95 Pb2I7, ( )2Rb 0.05 MA 0.95 Pb2I7, ( )2Rb 0.05 MA 0.95 One or more of Pb2I7.

[0101] In some embodiments, the second passivating material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds; wherein m≥1, and GA is C(NH2)3 + A2 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, the organic cations include one or more of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion and imidazolyl ion; B2 includes Pb 2+ Sn 2+ Be 2+ Mg 2 + Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3+ Fe 3+ and Cu 3+ One or more of the following; X2 includes I - Cl -,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0102] Satisfying the chemical formula (GA)A2 m B2 m X2 3m+1 The compound contains an ACI phase structure, which not only exists at the interface of the perovskite absorbing layer but also enters and is widely distributed in the bulk phase of the perovskite absorbing layer. Guanidinium and A2 ions alternately occupy the interlayer space of the perovskite absorbing layer bulk phase, promoting the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity. Simultaneously, the ACI phase structure distributed at the perovskite absorbing layer interface and entering the bulk phase can also increase the size and crystallinity of perovskite grains in the perovskite absorbing layer, further reducing the defect density at the perovskite absorbing layer interface and in the bulk phase. Therefore, the improved conductivity and reduced defect density can further enhance the efficiency and stability of perovskite solar cells.

[0103] In some embodiments, the second passivating material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds; wherein 1 ≤ m ≤ 10, and GA is C(NH2)3 + A2 includes MA + FA + Cs + and Rb + One or more of them, B2 includes Pb 2+ and Sn 2+ One or two of them, X2 includes I - Cl - ,Br - F - One or more of these. This is beneficial for further improving the efficiency and stability of perovskite solar cells.

[0104] In some embodiments, the second passivation material includes (GA)Cs 0.5 FA 0.5 PbI4, (GA)Cs 0.3 FA 0.7 PbI4, (GA)Cs 0.4 FA 0.6 PbI4, (GA)Cs 0.2 FA 0.8 PbI4, (GA)CsFAPb2I7, (GA)Cs1.4 FA 0.6 Pb₂I₇, (GA)Cs 0.5 FA 1.5 Pb₂I₇, (GA)CsFA₂Pb₃Cl 10 (GA)Cs2FAPb3I 10 (GA)Cs 1.4 FA 1.6 Pb3I 10 (GA)Cs 0.5 FA 0.5 SnI4, (GA)Cs 0.3 FA 0.7 SnI4, (GA)Cs 0.4 FA 0.6 SnI4, (GA)Cs 0.2 FA 0.8 SnI4、(GA)CsFASn2I7、(GA)Cs 1.4 FA 0.6 Sn2I7、(GA)Cs 0.5 FA 1.5 Sn2I7、(GA)CsFA2Sn3I 10 (GA)Cs2FASn3I 10 (GA)Cs 1.4 FA 1.6 Sn3I 10 (GA)(Cs) 0.05 FA 0.95 )2Pb2I7、(GA)(Cs 0.05 FA 0.95 )3Pb3I 10 (GA)(Cs) 0.05 FA 0.95 )4Pb4I 13 One or more of them.

[0105] As an example, the compositions of the first and second passivation materials in the passivation layer can be determined by testing using the following method:

[0106] Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) was used to monitor the F1s signal at different test angles, thereby determining the depth profile of the RP phase in the perovskite film. The X-ray photoelectron spectrum of this profile can reflect the compositional information of the RP phase (i.e., the first passivation material). Grazing incidence X-ray diffraction (GIXRD) was used to analyze the depth of the ACI phase in the bulk phase of the perovskite film by extracting the integral characteristic peak area ratio of ACI (12.96°) and 3D (14.13°) from the GIXRD data. The X-ray photoelectron spectrum within this depth range can reflect the compositional information of the ACI phase (i.e., the second passivation material).

[0107] In some embodiments, the mass ratio of the first passivating material to the second passivating material is (0.2~0.8):(1~4). For example, the mass ratio of the first passivating material to the second passivating material can be 0.2:4, 0.3:4, 0.4:4, 0.5:4, 0.6:4, 0.7:4, 0.8:4, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, or within any range of the above values. Optionally, the mass ratio of the first passivating material to the second passivating material is (0.1~0.4):1.

[0108] This allows the synergistic effect between the first and second passivation materials to be better utilized, thereby effectively reducing defects at the grain boundaries and in the bulk phase of the perovskite light-absorbing layer, suppressing non-radiative recombination, and promoting charge transfer at the interface of the perovskite light-absorbing layer, ultimately improving the efficiency and stability of perovskite solar cells.

[0109] In some embodiments, the perovskite light-absorbing layer comprises a perovskite material, which includes one or more compounds satisfying the chemical formula A'B'X'3 or A'2C'D'X'6. Wherein, A' ion is a monovalent cation, B' ion is a divalent cation, C' ion is a monovalent cation, D' ion is a trivalent cation, and X' ion is a monovalent anion. A' ion includes organic cations, Li... + Na + K + 、Rb + and Cs + One or more of the following; organic cations include at least one of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion, and imidazolyl ion; B' ion includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ and Ni 2+ One or more of the following; C' ions include Cs + Ag + K + and Ru + One or more of the following; D' ions include Bi 3+ Sb 3+Cr 3+ Fe 3+ Co 3+ Ga 3+ As 3+ Ru 3+ ,Rh 3+ In 3+ Ir 3+ Au 3+ Or Al 3+ One or more of the following; X' ions include F - Cl - ,Br - I - CN - SeCN - SCN - OCN - One or more of them.

[0110] In some embodiments, the perovskite light-absorbing layer includes a second passivation material. It is understood that the second passivation material included in the perovskite light-absorbing layer is the same as the second passivation material included in the passivation layer. The second passivation material distributed in the perovskite light-absorbing layer can increase the size and crystallinity of the perovskite grains in the perovskite light-absorbing layer, reduce the defect density at the perovskite light-absorbing layer interface and in the bulk phase, and improve the efficiency and stability of the perovskite solar cell.

[0111] As an example, the second passivation material (ACI phase) contained in the perovskite absorbing layer can be detected by the following method: using grazing incidence X-ray diffraction (GIXRD), the integral characteristic peak area ratio of the ACI phase (approximately 12.96°) and the three-dimensional perovskite phase (approximately 14.13°) in the perovskite absorbing layer is extracted from the GIXRD data to analyze the change in ACI phase content with increasing detection depth; by changing the incident angle from 0.5° to 3° and the detection depth from approximately 70 nm in the perovskite film bulk phase to approximately 500 nm, the integral area ratio decreases rapidly with increasing depth until it tends to plateau, which means that the ACI phase content decreases from the perovskite surface to the bulk phase; the intersection point can represent the approximate depth of the ACI phase, and finally the distribution depth range of the ACI phase in the perovskite absorbing layer can be obtained.

[0112] In some embodiments, the perovskite light-absorbing layer comprises perovskite grains with an average grain size of 590 nm to 1280 nm. For example, the average grain size of the perovskite grains can be 590 nm, 650 nm, 730 nm, 860 nm, 970 nm, 1010 nm, 1160 nm, 1280 nm, or any value within the range above. The ACI phase structure contained in the second passivation material can increase the size and crystallinity of the perovskite grains in the perovskite light-absorbing layer and keep the average grain size of the perovskite grains within the above range. This helps to reduce the defect density at the interface and in the bulk phase of the perovskite light-absorbing layer, thereby improving the efficiency and stability of the perovskite solar cell.

[0113] The average grain size of perovskite grains is a term known in the art and can be measured using methods known in the art. For example, it can be measured using a scanning electron microscope; during measurement, the grains can be observed and measured on a unit area of ​​the perovskite absorbing layer. For example, at multiples of 30K, a unit area (e.g., 2.5 μm × 2.5 μm) of the perovskite absorbing layer surface is scanned, and the maximum radius of several (e.g., 10) grains within this area is measured. The average grain size can be obtained by averaging the values.

[0114] In some embodiments, the thickness of the passivation layer is 2 nm to 5 nm. For example, the thickness of the passivation layer can be 2 nm, 3 nm, 4 nm, 5 nm, or within any range of the above values.

[0115] As an example, the thickness of the passivation layer can be detected by the following method: using angle-resolved X-ray photoelectron spectroscopy (AR-XPS), the F1s signal is monitored at different test angles from 0° to 60° to reveal the depth profile of the RP phase; as the takeoff angle increases from 0° to 60°, the detection depth is 5nm to 1nm, thereby detecting the thickness of the RP phase on the surface of the passivated perovskite film, which is the thickness of the passivation layer (where λcosθ represents the detection depth, and λ is the average diffusion length of electrons in the perovskite film, which increases as the takeoff angle decreases, indicating that a larger takeoff angle reflects the elemental composition closer to the surface of the perovskite film).

[0116] In some implementations, see Figure 1 Perovskite solar cells also include:

[0117] First charge transport layer 12 and / or second charge transport layer 13;

[0118] A first charge transport layer 12 is disposed on the side of the perovskite light-absorbing layer 10 away from the passivation layer 11, and / or, and / or, a second charge transport layer 13 is disposed on the side of the passivation layer 11 away from the perovskite light-absorbing layer 10, wherein the first charge transport layer 12 is one of an electron transport layer or a hole transport layer, and the second charge transport layer 13 is the other of an electron transport layer or a hole transport layer. By providing the first charge transport layer 12 and / or the second charge transport layer 13, it is beneficial to extract and transport the charge carriers (holes and / or electrons) generated by the perovskite light-absorbing layer 10, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0119] In some embodiments, the perovskite solar cell may simultaneously include a first charge transport layer 12 and a second charge transport layer 13. That is, the perovskite solar cell includes a first charge transport layer 12, a perovskite light-absorbing layer 10, a passivation layer 11, and a second charge transport layer 13 stacked sequentially. The first charge transport layer 12 is either an electron transport layer or a hole transport layer, and the second charge transport layer 13 is either an electron transport layer or a hole transport layer. The opposite charge transport properties of the first charge transport layer 12 and the second charge transport layer 13 facilitate the transport and extraction of electrons and holes, thus improving the photoelectric conversion efficiency of the perovskite solar cell. In other embodiments, the perovskite solar cell includes only the first charge transport layer 12, or only the second charge transport layer 13.

[0120] In some embodiments, the first charge transport layer 12 is a hole transport layer and the second charge transport layer 13 is an electron transport layer. In other embodiments, the first charge transport layer 12 is an electron transport layer and the second charge transport layer 13 is a hole transport layer.

[0121] In some embodiments, the electron transport layer is used to extract and transport electrons. The electron transport layer may include, but is not limited to, one or more of the following materials and their derivatives: 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 thereof. Exemplarily, imide compounds include at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide, or maleimide. Exemplarily, quinone compounds include at least one of benzoquinone, naphthoquinone, phenanthrenequinone, or anthraquinone. Exemplarily, fullerenes and their derivatives include fullerene C60, fullerene C70, and PC. 61 BM ([6,6]-phenyl-C61-butyrate methyl ester), [6,6]-phenyl-C71-butyrate methyl ester (PC) 71At least one of 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 dioxide (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.

[0122] In some embodiments, the hole transport layer may include, but is not limited to, one or more of the following materials and their derivatives: 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), nickel oxide (NiO2). x Materials such as poly(3,4-ethylenedioxythiophene), polystyrene sulfonate (PEDOT:PSS), SAM (Self-Assembled Monolayer), and WO3 can transport holes and block electrons.

[0123] In some embodiments, SAM (Self-Assembled Monolayer) includes one or more of 4-(9H-carbazole-9-yl)butylphosphonic acid (4PACz), (4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid (Me-4PACz), (2-(9H-carbazole-9-yl)ethylphosphonic acid (2PACz), 2-(3,6-dimethoxy-9H-carbazole-9-yl)ethylphosphonic acid (MeO-2PACz), and (4-(3,6-diphenyl-9H-carbazole-9-yl)butylphosphonic acid (Ph-4PAC).

[0124] In some implementations, see Figure 1 The perovskite solar cell also includes a first electrode 14 and a second electrode 15; the first electrode 14 is disposed on the side of the perovskite light-absorbing layer 10 away from the passivation layer 11, and the second electrode 15 is disposed on the side of the passivation layer 11 away from the perovskite light-absorbing layer 10. The first electrode 14 and the second electrode 15 are arranged to collect electrons and holes generated by the perovskite light-absorbing layer 10, and to extract the generated photocurrent.

[0125] In some embodiments, one of the "first electrode 14" and the "second electrode 15" is a transparent electrode for light incident. Specifically, one of the first electrode 14 and the second electrode 15 is used to collect electron carriers, and the other is used to collect hole carriers.

[0126] In some embodiments, the materials of the first electrode 14 and the second electrode 15 may each be independently one or more of organic conductive materials, inorganic conductive materials, or organic-inorganic mixed conductive materials, and at least one of them is a transparent electrode for light incident. Optionally, the electrode materials include one or more of transparent conductive metal oxides, carbon, metals and their alloys. More preferably, the transparent conductive metal oxides include one or more of indium tin oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), zinc aluminum oxide (AZO), indium zinc oxide (IZO), zinc gallium oxide (GZO), and indium tungsten oxide (IWO); the metals and their alloys include one or more of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W and their alloys; and the carbon materials include one or more of graphite, graphene, and carbon nanotubes.

[0127] In some embodiments, the perovskite solar cell includes a first electrode 14, a first charge transport layer 12, a perovskite light-absorbing layer 10, a passivation layer 11, a second charge transport layer 13, and a second electrode 15, stacked sequentially. When the first electrode 14 is a transparent electrode for light incident, and the first charge transport layer 12 and the second charge transport layer 13 are a hole transport layer and an electron transport layer, respectively, the resulting perovskite solar cell is an inverted perovskite solar cell (PIN). In other embodiments, the perovskite solar cell includes a first electrode 14, a first charge transport layer 12, a perovskite light-absorbing layer 10, a passivation layer 11, a second charge transport layer 13, and a second electrode 15, stacked sequentially. When the first electrode 15 is a transparent electrode for light incident, and the first charge transport layer 12 and the second charge transport layer 13 are a hole transport layer and an electron transport layer, respectively, the resulting perovskite solar cell is a standard perovskite solar cell (NIP). Optionally, the first electrode 14 is a transparent electrode, resulting in an inverted solar cell, which exhibits better stability.

[0128] In some embodiments, the perovskite solar cell further includes a substrate layer for supporting the perovskite solar cell. The substrate layer is disposed on the side of the first electrode layer that is relatively far from the perovskite light-absorbing layer, or the substrate layer is disposed on the side of the second electrode layer that is relatively far from the perovskite light-absorbing layer.

[0129] In some embodiments, the substrate layer may be, but is not limited to, a glass substrate or a flexible substrate. The flexible substrate may include one or more materials selected from polyethylene terephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, etc.

[0130] It is understood that the structure of the perovskite solar cell involved in this application is not limited to the structural layers listed above. Other functional layers, such as buffer layers, can also be introduced as needed. In some embodiments, a buffer layer with appropriate energy levels can be provided in the perovskite solar cell, which can play one or more of the following roles: reducing the energy level barrier, promoting energy level matching, improving carrier extraction efficiency, passivating interface defect states, protecting the light absorption layer, inhibiting the oxidative decomposition of the cell by water molecules and oxygen, improving photoelectric conversion efficiency, and improving the stability of the perovskite cell. Depending on the location of the buffer layer, the type of buffer layer may include four types: a buffer layer between the hole transport layer and the anode, a buffer layer between the electron transport layer and the cathode, a buffer layer between the hole transport layer and the light absorption layer, and a buffer layer between the electron transport layer and the light absorption layer.

[0131] In some embodiments, see Figure 1 The buffer layer is a barrier layer 16 between the second charge transport layer 13 and the second electrode layer 15. The material of the barrier layer 16 may include one or more of SnO2 and copper bath (BCP, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0132] Secondly, this application provides a perovskite solar cell, which corresponds to the perovskite solar cell of the first aspect of this application, comprising:

[0133] Perovskite light-absorbing layer, and

[0134] A passivation layer is disposed on one side of the perovskite light-absorbing layer. The raw materials for preparing the passivation layer include a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

[0135] It should be noted that the "hydrocarbon ammonium salt" mentioned in this application refers to a compound formed by replacing one hydrogen atom of an ammonium ion with a hydrocarbon group; the "hydrocarbon group" refers to the part remaining after removing one or more hydrogen atoms from a hydrocarbon (hydrocarbon) molecule, which may include one or more of saturated alkyl, unsaturated hydrocarbon, aryl and arylalkyl groups.

[0136] The raw materials for preparing the passivation layer include a first passivation precursor material and a second passivation precursor material. During the preparation of the passivation layer, the first passivation precursor material and the second passivation precursor material will react with the interface of the perovskite light-absorbing layer or even some components in the bulk phase. At the same time, the first passivation precursor material and the second passivation precursor material may also interact with each other, thereby forming RP phase structure and ACI phase structure respectively, and thus forming the first passivation material, the second passivation material, and the passivation layer.

[0137] Thirdly, this application provides a method for preparing a perovskite solar cell, which can be used to prepare the perovskite solar cell of the first or second aspect of this application, comprising:

[0138] A perovskite light-absorbing layer and a passivation layer are formed, with the passivation layer located on one side of the perovskite light-absorbing layer;

[0139] The passivation layer comprises a first passivation material and a second passivation material. The first passivation material contains an RP phase structure and contains fluorine, while the second passivation material contains an ACI phase structure.

[0140] The perovskite solar cell prepared by the method provided in this application has a passivation layer formed on one side of the perovskite light-absorbing layer. The first passivation material contained in the passivation layer is distributed at the interface of the perovskite light-absorbing layer and contains an RP phase structure and fluorine. The RP phase structure enables the first passivation material to form a two-dimensional-three-dimensional heterojunction with the three-dimensional perovskite material in the perovskite light-absorbing layer, which can passivate defects and suppress non-radiative recombination at the interface. On this basis, the presence of fluorine can significantly improve the positive charge of the spatial cations in the RP phase structure, thereby significantly improving the adsorption of the first passivation material on the negatively charged surface of the perovskite light-absorbing layer, thus achieving an effective interface passivation effect, effectively reducing the occurrence of non-radiative recombination at the interface, and improving the efficiency and stability of the perovskite solar cell.

[0141] The second passivation material containing the ACI phase structure in the passivation layer not only exists at the interface of the perovskite light-absorbing layer but also enters the bulk phase of the perovskite light-absorbing layer. Furthermore, the space cations in the ACI phase structure alternately occupy the interlayer space of the perovskite light-absorbing layer bulk phase, promoting the extraction and transfer of charge carriers during charge transport, thereby effectively improving conductivity. At the same time, the ACI phase structure distributed at the interface of the perovskite light-absorbing layer and entering the bulk phase can also increase the size and crystallinity of the perovskite grains in the perovskite light-absorbing layer, further reducing the defect density at the interface and in the bulk phase of the perovskite light-absorbing layer. Thus, the improvement in conductivity and the reduction in defect density can further improve the efficiency and stability of perovskite solar cells.

[0142] Furthermore, the first passivation material and the second passivation material can work together to effectively reduce defects at the grain boundaries and in the bulk phase of the perovskite light-absorbing layer, suppress non-radiative recombination, and promote charge transfer at the interface of the perovskite light-absorbing layer, thereby effectively improving the efficiency and stability of perovskite solar cells.

[0143] In some implementations, forming the passivation layer includes:

[0144] The passivation precursor solution is coated on one side of the perovskite light-absorbing layer, and the passivation layer is obtained after annealing.

[0145] The passivation precursor solution contains a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

[0146] When the passivation precursor solution is coated on one side of the perovskite light-absorbing layer and annealed, the first passivation precursor material and the second passivation precursor material will form RP phase structure and ACI phase structure, thereby forming the first passivation material and the second passivation material, as well as the passivation layer. The RP phase structure and the ACI phase structure work together to reduce non-radiative recombination and interface defects, thereby improving device efficiency and stability.

[0147] In some embodiments, the fluorinated alkyl ammonium salt comprises one or more compounds satisfying the chemical formula R'NH3Y1; wherein R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated alkyl groups, fluorinated aryl groups, and fluorinated arylalkyl groups, and Y1 comprises I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0148] When a compound satisfying the chemical formula R'NH3Y1 is coated on one side of a perovskite light-absorbing layer and annealed, it reacts with some components at the interface of the perovskite light-absorbing layer to generate a compound satisfying the chemical formula (R)2A1. n-1 B1 n X1 3n+1 The first passivation material is formed in the process of forming an RP phase structure; wherein, R' enables the first passivation precursor material to be widely distributed throughout the entire interface of the perovskite light-absorbing layer, which is beneficial to improving its effect on the perovskite light-absorbing layer.

[0149] In some embodiments, fluorine-containing hydrocarbon ammonium salts include p-fluorophenylethylamine iodine (… ), o-fluorophenylethylamine iodine ( ), m-fluorophenylethylamine iodine ( ) and trifluoroethylamine iodine ( One or more of the following, optionally p-fluorophenylethylamine iodide. P-fluorine-substituted phenylethylammonium iodide can significantly increase the NH3 content. + The positive charge at the end can significantly improve the adsorption of the first passivation material formed therefrom on the negatively charged perovskite light-absorbing layer surface, thereby achieving a good interface passivation effect, effectively reducing the occurrence of non-radiative recombination at the interface, and improving the efficiency and stability of perovskite solar cells.

[0150] In some embodiments, the guanidine salt comprises one or more compounds satisfying the chemical formula GAY2, where GA is C(NH2)3. + Y2 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

[0151] When a compound satisfying the chemical formula GAY2 is coated on one side of a perovskite light-absorbing layer and annealed, it reacts with some components at the interface of the perovskite light-absorbing layer and in the bulk phase to generate a compound satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 The second passivating material is formed in the process, and an ACI phase structure is formed.

[0152] In some embodiments, guanidine salts include guanidine chloride ( ), guanidine bromide ( ), guanidine iodide ( One or more of the following.

[0153] In some embodiments, the mass ratio of the first passivation precursor material to the second passivation precursor material is (0.2~0.8):(1~4); alternatively, it can be (0.1~0.4):1. For example, the mass ratio can be 0.2:4, 0.3:4, 0.4:4, 0.5:4, 0.6:4, 0.7:4, 0.8:4, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, or within any range of the above values. By controlling the mass ratio of the first passivation precursor material to the second passivation precursor material within a suitable range, it is not only beneficial to the formation of the RP phase structure and the ACI phase structure and their interaction, but also to improve the morphology of the perovskite light-absorbing layer, increase the average grain size of the perovskite grains in the perovskite light-absorbing layer and make the grain size distribution more uniform, make the surface of the perovskite light-absorbing layer more dense, and reduce the residue of the perovskite precursor liquid, thereby reducing the surface defects of the perovskite light-absorbing layer and improving the efficiency and stability of the perovskite solar cell.

[0154] Fourthly, this application also provides a photovoltaic module, including a perovskite solar cell of the first aspect of this application, a perovskite solar cell of the second aspect of this application, and a perovskite solar cell prepared by the method of the second aspect of this application.

[0155] In some embodiments, a photovoltaic module may include only the perovskite solar cells of the first or second aspect of this application, or may combine perovskite solar cells with other solar cells. For example, a perovskite solar cell may be combined with a silicon solar cell.

[0156] Fifthly, this application also provides an electrical device, including one or more of the following: the perovskite solar cell of the first aspect of this application, the perovskite solar cell of the second aspect of this application, the perovskite solar cell prepared by the method of the third aspect of this application, and the photovoltaic module of the fourth aspect of this application.

[0157] In some embodiments, the electrical device may include mobile devices such as mobile phones, laptops, electric vehicles, electric trains, ships and satellites, power generation systems, etc., but is not limited thereto. Figure 4 This is just one example of an electrical device. The electrical device is a car, and more specifically, a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. Another example of an electrical device could be a wearable device, such as a watch.

[0158] In a sixth aspect, this application also provides a power generation device, including one or more of the perovskite solar cell of the first aspect of this application, the perovskite solar cell of the second aspect of this application, the perovskite solar cell prepared by the method of the third aspect of this application, and the photovoltaic module of the fourth aspect of this application.

[0159] In some embodiments, 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 or back panel of a vehicle.

[0160] Example

[0161] 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.

[0162] 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.

[0163] Example 1

[0164] 1) Preparation of the first electrode layer

[0165] Take 20 pieces of FTO conductive glass with a size of 2.0×2.0 cm, remove 0.35 cm of FTO from each end by laser etching to expose the glass substrate; ultrasonically clean the etched FTO conductive glass several times with cleaning solution, deionized water and ethanol in sequence; then blow the solvent dry under a nitrogen gun and put it into an ultraviolet ozone generator for further cleaning.

[0166] 2) Fabrication of the hole transport layer

[0167] SAM (ethanol as solvent, concentration 10 mg / mL) was prepared by spin-coating on a substrate exposed to ultraviolet light. The spin-coating was performed at 5000 rpm for 30 seconds and then annealed at 100 °C for 10 minutes to obtain a 2 nm hole transport layer. The SAM was 2-(3,6-dimethoxy-9H-carbazole-9-yl)ethylphosphonic acid (MeO-2PACz).

[0168] 3) Preparation of the perovskite light-absorbing layer

[0169] 19.485 mg CsI, 694.972575 mg PbI2, and 245.05725 mg FAI were dissolved in 800 μL DMF and 200 μL DMSO and stirred for 30 minutes to obtain a perovskite precursor solution. Under a nitrogen atmosphere, the perovskite precursor solution was dropwise added to the surface of the hole transport layer, and spin-coated at 1000 rpm for 10 seconds, followed by spin-coating at 5000 rpm for 30 seconds, during which 150 μL of anisole was injected as an antisolvent. The resulting film was annealed at 150 °C for 10 minutes to obtain a 500 nm perovskite light-absorbing layer, in which the perovskite material was CsI. 0.05 FA 0.95 PbI3.

[0170] 4) Preparation of passivation layer

[0171] 0.6 mg of p-fluorophenylethylamine iodine and 2 mg of guanidine chloride were dissolved in 1 mL of isopropanol to form a passivation precursor solution (the mass ratio of the two raw materials was 0.6:2). The passivation precursor solution was spin-coated onto the surface of the perovskite light-absorbing layer at 5000 rpm and held for 30 s. Then, it was thermally annealed at 100 °C for 5 min to form a 3 nm passivation layer.

[0172] 5) Fabrication of the electron transport layer

[0173] C60 was deposited onto the surface of the passivation layer by thermal evaporation, with a coating thickness of 27 nm.

[0174] 6) Preparation of hole blocking layer

[0175] A 30nm tin oxide layer was deposited on the surface of the electron transport layer using an atomic layer deposition apparatus to form a hole blocking layer.

[0176] 7) Fabrication of the second electrode layer

[0177] A copper electrode with a thickness of 100 nm is thermally deposited on the surface of the hole blocking layer.

[0178] Example 2

[0179] The preparation process is similar to that in Example 1, the main difference is that in step 4), the mass of phenylethylamine iodine and guanidine chloride are 0.3 mg and 2 mg, respectively, so that the mass ratio of the two is 0.3:2.

[0180] Example 3

[0181] The preparation process is similar to that in Example 1, the main difference is that in step 4), the mass of fluorophenylethylamine iodine and guanidine chloride are 0.8 mg and 2 mg, respectively, so that the mass ratio of the two is 0.8:2.

[0182] Example 4

[0183] The preparation process is similar to that in Example 1, the main difference is that in step 4), the mass of 1 mg of fluorophenethylamine iodine and 2 mg of guanidine chloride are respectively, so that the mass ratio of the two is 1:2.

[0184] Example 5

[0185] The preparation process is similar to that of Example 1, except that in step 4), an equal mass of m-fluorophenylethylamine iodine is used instead of p-fluorophenylethylamine iodine.

[0186] Example 6

[0187] The preparation process is similar to that of Example 1, except that in step 4), p-fluorophenylethylamine iodine is replaced with an equal mass of trifluoroethylamine iodine.

[0188] Comparative Example 1

[0189] The preparation process is similar to that of Example 1, except that in step 4), no iodine-p-fluorophenethylamine is added, and the amount of guanidine chloride added is 2.6 mg.

[0190] Comparative Example 2

[0191] The preparation process is similar to that of Example 1, except that in step 4), guanidine chloride is not added and the amount of 2.6 mg of fluorophenethylamine iodine is added.

[0192] Comparative Example 3

[0193] The preparation process is similar to that of Example 1, the main difference being that in step 4), 0.6 mg of phenethylamine iodine ( (i.e., fluorine substitution is omitted) instead of 0.6 mg of p-fluorophenethylamine iodine.

[0194] Comparative Example 4

[0195] The preparation process is similar to that of Example 1, with the main difference being that step 4 is omitted and no passivation layer is provided between the perovskite light-absorbing layer and the electron transport layer.

[0196] The parameters and performance test results of the above embodiments and comparative examples are shown in Tables 1 to 4 below.

[0197] Table 1

[0198]

[0199] Table 2

[0200]

[0201] Table 3

[0202]

[0203] Test methods

[0204] (1) Photoelectric conversion efficiency and conductive layer test

[0205] Under normal temperature and pressure, and under standard simulated sunlight (AM 1.5G, 100 milliwatts per square centimeter (mW / cm²) 2 Under illumination, the battery performance was tested to obtain the IV curve (volt-ampere characteristic curve). Based on the IV curve and the data fed back by the testing equipment (four-channel digital source meter, Keithley 2440), the short-circuit current density Jsc (mA / cm2), open-circuit voltage Voc (volts (V)), maximum light output current Jmpp (mA (mA)), maximum light output voltage Vmpp (V) and series resistance (Ω) can be obtained.

[0206] The fill factor FF of the battery can be calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp), in percentage. The photoelectric conversion efficiency PCE of the battery can be calculated using the formula PCE = Jsc × Voc × FF / Pw, in percentage; Pw represents the input power, in milliwatts (mW).

[0207] "Normal temperature and pressure" refers to normal pressure: the pressure is one atmosphere at a temperature of 25℃; normal temperature refers to 20℃ to 30℃, and further, it can be 25℃.

[0208] (2) Stability test

[0209] The perovskite solar cell was clamped in a test fixture and placed on a 55°C hot stage for continuous heating. Under N2 atmosphere and AM1.5 standard sunlight, the change in its photoelectric conversion efficiency over time was tracked. The time required for its photoelectric conversion efficiency to decay to 80% of its initial photoelectric conversion efficiency was recorded as T80, which is used to represent the stability of the perovskite solar cell.

[0210] Table 4

[0211]

[0212] Table 4 shows that when the examples are compared with Comparative Examples 1, 2, and 4, the perovskite solar cell of this application has a passivation layer, and when the passivation layer contains a first passivation material with an RP phase structure and a second passivation material with an ACI phase structure, it can effectively improve conductivity, cell efficiency, and stability. When the examples are compared with Comparative Example 3, it can be seen that when the first passivation material contains fluorine, it is beneficial to improve conductivity, cell efficiency, and stability.

[0213] In addition, from Figure 3 and Figure 4 The comparison shows that Example 1 contains the RP phase, while Comparative Example 1 does not contain the RP phase.

[0214] 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.

[0215] The above embodiments merely illustrate 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.

Claims

1. A perovskite solar cell, characterized in that, include: Perovskite light-absorbing layer, and A passivation layer is disposed on one side of the perovskite light-absorbing layer. The passivation layer comprises a first passivation material and a second passivation material. The first passivation material contains fluorine and has an RP phase structure, and the second passivation material contains an ACI phase structure.

2. The perovskite solar cell according to claim 1, characterized in that, The first passivation material comprises materials satisfying the chemical formula (R)2A1 n-1 B1 n X1 3n+1 One or more of the compounds; Where n≥1, R is R'-NH3 + R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated hydrocarbon groups, fluorinated aryl groups, and fluorinated arylalkyl groups; A1 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, wherein the organic cation includes one or more of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion and imidazolyl ion; B1 includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3+ Fe 3 + and Cu 3+ One or more of the following; X1 includes I - Cl - ,Br - F - CN - SCN - SeCN - and OCN - One or more of them.

3. The perovskite solar cell according to claim 2, characterized in that, In chemical formula (R)2A1 n-1 B1 n X1 3n+1 In the compounds: 1≤n≤20, R is R'-NH3 + R' is selected from one or more fluorinated C6-C10 aryl and fluorinated C7-C10 arylalkyl groups; A1 includes methylamino ion, formamidinium ion, and Cs. + and Rb + One or more of the following; B1 includes Pb 2+ and Sn 2+ One or two of them; X1 includes I - Cl - ,Br - F - One or more of them.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The second passivation material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds; Where m≥1, GA is C(NH2)3 + ; A2 includes organic cations, Li + Na + K + 、Rb + Cs + Ag + K + and Ru + One or more of the following, wherein the organic cation includes one or more of methylamino ion, ethylamino ion, propylamino ion, butylamino ion, pentamino ion, hexamino ion, formamidinyl ion and imidazolyl ion; B2 includes Pb 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ Ni 2+ Bi 3+ Ni 3+ Fe 3 + and Cu 3+ One or more of the following; X2 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

5. The perovskite solar cell according to any one of claims 1 to 4, characterized in that, The second passivation material comprises materials satisfying the chemical formula (GA)A2. m B2 m X2 3m+1 One or more of the compounds; Where 1≤m≤10, GA is C(NH2)3 + ; A2 includes methylamino ion, formamidinium ion, and Cs. + and Rb + One or more of the following; B2 includes Pb 2+ and Sn 2+ One or two of them; X2 includes I - Cl - ,Br - F - One or more of them.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that, The mass ratio of the first passivating material to the second passivating material is (0.2~0.8):(1~4).

7. The perovskite solar cell according to any one of claims 1 to 6, characterized in that, The mass ratio of the first passivating material to the second passivating material is (0.1~0.4):

1.

8. The perovskite solar cell according to any one of claims 1 to 7, characterized in that, One or more of the following conditions must be met: (1) The perovskite light-absorbing layer contains the second passivation material; (2) The perovskite light-absorbing layer contains perovskite grains, and the average grain size of the perovskite grains is 590 nm to 1280 nm. (3) The thickness of the passivation layer is 2nm~5nm.

9. The perovskite solar cell according to any one of claims 1 to 8, characterized in that, The perovskite solar cell also includes: First charge transport layer and / or second charge transport layer; The first charge transport layer is disposed on the side of the perovskite light-absorbing layer away from the passivation layer, and / or the second charge transport layer is disposed on the side of the passivation layer away from the perovskite light-absorbing layer, wherein the first charge transport layer is one of an electron transport layer or a hole transport layer, and the second charge transport layer is the other of an electron transport layer or a hole transport layer.

10. The perovskite solar cell according to any one of claims 1 to 9, characterized in that, The perovskite solar cell further includes a first electrode and a second electrode; The first electrode is disposed on the side of the perovskite light-absorbing layer away from the passivation layer, and the second electrode is disposed on the side of the passivation layer away from the perovskite light-absorbing layer.

11. A perovskite solar cell, characterized in that, include: Perovskite light-absorbing layer, and A passivation layer is disposed on one side of the perovskite light-absorbing layer. The raw materials for preparing the passivation layer include a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

12. A method for preparing perovskite solar cells, characterized in that, include: Formation of a perovskite light-absorbing layer; A passivation precursor solution is coated on one side of the perovskite light-absorbing layer, and after annealing, a passivation layer is formed to prepare a perovskite solar cell. The passivation precursor solution contains a first passivation precursor material and a second passivation precursor material. The first passivation precursor material includes a fluorine-substituted hydrocarbon ammonium salt, and the second passivation precursor material includes a guanidine salt.

13. The method according to claim 12, characterized in that, One or more of the following conditions must be met: (1) The fluorine-substituted hydrocarbon ammonium salt includes one or more compounds that satisfy the chemical formula R'NH3Y1; Wherein, R' is selected from one or more of fluorinated C2-C10 saturated alkyl groups, fluorinated C3-C10 unsaturated hydrocarbon groups, fluorinated aryl groups, and fluorinated arylalkyl groups, and Y1 includes I. - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of the following; (2) The guanidine salt includes one or more compounds that satisfy the chemical formula GAY2, where GA is C(NH2)3. + Y2 includes I - Cl - ,Br - F - CN - SeCN - SCN - and OCN - One or more of them.

14. The method according to claim 12 or 13, characterized in that, The mass ratio of the first passivation precursor material to the second passivation precursor material is (0.2~0.8):(1~4).

15. A photovoltaic module, characterized in that, This includes the perovskite solar cell according to any one of claims 1 to 10, the perovskite solar cell according to claim 11, and the perovskite solar cell prepared by the method according to any one of claims 12 to 14.

16. An electrical appliance, characterized in that, It includes one or more of the following: the perovskite solar cell according to any one of claims 1 to 10, the perovskite solar cell according to claim 11, the perovskite solar cell prepared by the method according to any one of claims 12 to 14, and the photovoltaic module according to claim 15.

17. A power generation device, characterized in that, It includes one or more of the following: the perovskite solar cell according to any one of claims 1 to 10, the perovskite solar cell according to claim 11, the perovskite solar cell prepared by the method according to any one of claims 12 to 14, and the photovoltaic module according to claim 15.

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