Solar cell and manufacturing method therefor, photovoltaic module, electric device, and power generation device

Abstract

The present application provides a solar cell and a manufacturing method therefor, a photovoltaic module, an electric device, and a power generation device. The solar cell comprises a first electrode layer, a composite perovskite layer, and a second electrode layer; the composite perovskite layer is located between the first electrode layer and the second electrode layer; the composite perovskite layer comprises a perovskite material and a passivation material; the passivation material comprises a heterocyclic compound; heterocyclic atoms of the heterocyclic compound at least include N; and the heterocyclic compound further comprises one or more substituents R1 located on a heterocyclic ring, wherein R1 each independently comprises an active group R2, and the active group R2 comprises one or more of an amino group and an amine salt thereof, a sulfhydryl group, an alkylthio group, an alkoxy group, a cyanate group, an amide group, a halogen, an organic acid group, and salts thereof.

Description

Solar cells and their fabrication methods, photovoltaic modules, electrical appliances and power generation devices

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 2025101853885, filed on February 19, 2025, entitled "Solar Cell and Preparation Method Thereof, Photovoltaic Module, Electrical Device and Power Generation Device", 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, an electrical device, and a power generation device. Background Technology

[0004] A solar cell is a new type of photovoltaic device that uses the photovoltaic effect to directly convert solar radiation energy into electrical energy.

[0005] Taking perovskite solar cells as an example, they use perovskite materials as the light-absorbing layer and have the advantages of low cost, high low light effect and wide application scenarios. They are an excellent choice for the next generation of mass-produced photovoltaic cells, which can alleviate the energy crisis and are one of the key development directions of new energy.

[0006] However, the photoelectric conversion efficiency of solar cells in practical applications is still relatively low. Summary of the Invention

[0007] To achieve the above objectives, this application provides a solar cell and its fabrication method, a photovoltaic module, an electrical device, and a power generation device. This solar cell has improved photoelectric conversion efficiency.

[0008] A first aspect of this application provides a solar cell comprising a first electrode layer, a composite perovskite layer, and a second electrode layer, wherein the composite perovskite layer is located between the first electrode layer and the second electrode layer, the composite perovskite layer comprising a perovskite material and a passivation material, the passivation layer comprising a heterocyclic compound, wherein the heterocyclic atom of the heterocyclic compound comprises at least N, and the heterocyclic compound further comprises one or more substituents R located on the heterocycle. 1 R 1 Each independently includes an active group R. 2 The active group R 2 It includes one or more of the following: amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

[0009] In the aforementioned solar cell of this application, a passivation material is used to passivate the composite perovskite layer. This passivation material also contains heterocyclic compounds, wherein the heterocyclic atoms of the heterocyclic compounds include nitrogen (N) elements. The N elements possess lone pair electrons that can coordinate with the B-site metal of the perovskite layer. One or more substituents R on the heterocyclic compounds... 1 Contains a specific type of active group R 2 active group R 2 It can interact with the perovskite layer to passivate defects or inhibit ion migration. In this way, the synergistic effect of heterocycles and substituents can effectively passivate defects on the surface of the perovskite layer, reduce non-radiative recombination at the perovskite layer interface, and help improve the photoelectric conversion efficiency and stability of solar cells.

[0010] In some embodiments, one or more of the following features are satisfied:

[0011] (1) The heterocyclic compound includes multiple substituents R located on the heterocycle. 1 There are at least two Rs 1 The active group R in 2 Different types;

[0012] (2) At least one R 1 The active group R in 2 This includes various groups such as amine groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

[0013] Thus, two different types of active groups R 2 This can provide more diverse active sites, improving the passivation effect on perovskite layers. And / or, through an R 1 The active group R in 2 It can provide more different active sites, and can passivate both deep and shallow level defects in perovskite films at the same time, thus improving the passivation effect on the perovskite layer.

[0014] In some of these embodiments, at least one R 1 The active group R in 2 This includes one or more amine groups and their amine salts. The amine group can provide lone pair electrons to bind with uncoordinated lead ions, thereby passivating defects. This effect reduces nonradiative charge recombination and increases carrier lifetime. Furthermore, it can provide hydrogen bonding, enhancing the bond between the molecule and the perovskite surface and improving stability.

[0015] In some of these embodiments, at least one R 1 The active group R in 2Including one or more of mercapto, alkylthio, alkoxy, cyano, amide, halogen, organic acid groups and their salts, and one or more of amine groups and their amine salts; optionally, at least one R 1 The active group R in 2 Combinations of cyanate and amino groups, and more specifically -NH-CN, are possible. This combination can simultaneously passivate the cations (Pb) on the perovskite surface. 2+ ) and anion (I - (Defects) to achieve more comprehensive defect repair.

[0016] In some embodiments, one or more of the following conditions are met:

[0017] (1) The heterocyclic compounds include aromatic heterocyclic compounds;

[0018] (2) The heterocycles in the heterocyclic compounds have 5 to 6 ring atoms;

[0019] (3) The heterocyclic atoms of the heterocyclic compounds also include one or both of O and S.

[0020] In some embodiments, the heterocycles in the heterocyclic compounds include one or more of the following: thiadiazole ring, thiazolium ring, oxadiazole ring, imidazole ring, and pyridine ring.

[0021] Aromatic rings (such as benzene rings) can bind to the perovskite surface through π-π interactions or electrostatic interactions, reducing X-site-related defects such as neutral iodine.

[0022] In some embodiments, the heterocyclic compounds include one or more of 2,5-dimercaptothiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 5-amino-1,2,3-thiadiazole, 4-methoxypyridinecarboxamide, amitevir, 1,3,4-oxadiazole-2,5-diamine, 1,3,4-oxadiazole-2,5-diamine hydroiodate, 5-cyanothiazole, and 7-bromo-1H-benzimidazole-5-amine. These multi-site heterocyclic compounds can simultaneously passivate various defects on the perovskite surface, significantly reducing 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 contributing to improved photoelectric conversion efficiency of the solar cell.

[0023] In some embodiments, the composite perovskite layer comprises a mixture of perovskite materials and passivation materials;

[0024] Alternatively, the composite perovskite layer includes a perovskite body layer and a passivation layer, wherein the perovskite body layer is located between the first electrode layer and the second electrode layer, and the passivation layer is disposed between the perovskite body layer and the second electrode layer. The perovskite body layer includes the perovskite material, and the passivation layer includes the passivation material. Optionally, the thickness of the passivation layer is 0.1 nm to 20 nm.

[0025] Perovskite material and passivation material are co-contained in the same film layer. The passivation material, added as an additive to the perovskite layer, has a crystallization-regulating effect, thereby reducing bulk defects. This crystallization regulation improves the crystallinity of the perovskite film, reduces the defect state density at grain boundaries, and thus enhances the photoelectric conversion efficiency of the device.

[0026] Alternatively, a passivation layer can be used to passivate the surface of the perovskite bulk layer, reducing the defect state density at the interface and thus improving the photoelectric conversion efficiency of the device.

[0027] In some embodiments, one or more of the following features are satisfied:

[0028] (1) The solar cell further includes a first charge transport layer, which is disposed between the composite perovskite layer and the second electrode layer; optionally, the first charge transport layer is an electron transport layer.

[0029] (2) The solar cell further includes a second charge transport layer, which is disposed between the first electrode layer and the composite perovskite layer; optionally, the second charge transport layer is a hole transport layer.

[0030] In some embodiments, the first electrode layer is a transparent electrode.

[0031] The second aspect of this application provides a method for preparing a solar cell, comprising the following steps:

[0032] A first electrode layer, a composite perovskite layer, and a second electrode layer are formed in a stacked configuration.

[0033] The composite perovskite layer comprises a perovskite material and a passivation material. The passivation material comprises a heterocyclic compound, wherein the heterocyclic atom of the heterocyclic compound includes at least N, and the heterocyclic compound further comprises one or more substituents R located on the heterocycle. 1 R 1 Each independently includes an active group R. 2 The active group R 2 It includes one or more of the following: amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

[0034] In some embodiments, forming the composite perovskite layer includes the following steps:

[0035] Formation of the perovskite bulk layer;

[0036] A passivation solution containing the heterocyclic compound was coated onto the perovskite bulk layer, and then annealed to obtain the passivation layer.

[0037] Optionally, the concentration of the heterocyclic compound in the passivation solution is 0.05 mg / mL to 10 mg / mL, and optionally 0.2 mg / mL to 5 mg / mL;

[0038] Optionally, the annealing treatment is performed at a temperature of 80°C to 150°C for a time of 1 min to 30 min.

[0039] In a third aspect, this application provides a photovoltaic module, including the solar cell of the first aspect of this application or the solar cell prepared by the preparation method of the second aspect of this application.

[0040] In a fourth aspect, this application provides an electrical device, including a solar cell according to the first 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 third aspect of this application.

[0041] In a fifth aspect of this application, a power generation device is provided, including a solar cell according to the first 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 third aspect of this application.

[0042] 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.

[0043] 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

[0044] 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:

[0045] Figure 1 is a schematic diagram of a solar cell according to an embodiment of this application.

[0046] Explanation of reference numerals in the attached figures: 1. Solar cell; 11. Substrate; 12. First electrode layer; 13. Second charge transport layer; 14. Perovskite bulk layer; 15. Passivation layer; 16. First charge transport layer; 17. Second electrode layer. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0051] 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.

[0052] 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) may 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] In this application, "arylamino group" refers to a group 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. Suitable examples include, but are not limited to, triphenylamino group.

[0058] In this application, "heteroaryl" refers to an aryl group in which at least one cyclic 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-C30 heteroaryl" refers to a heteroaryl group containing 3 to 20 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.

[0059] 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.

[0060] In this application, the single bonds connecting the substituents extend through the corresponding ring, indicating that the substituent can be connected to any optional position on the ring.

[0061] In this application, "halogen" refers to F, Cl, Br, and I.

[0062] 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 layer, where it is absorbed. Under the excitation of the incident light, the perovskite 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. Subsequently, a circuit is formed through an external circuit, which can be used to drive a load.

[0063] Compared to other solar cells, perovskite solar cells exhibit higher theoretical photoelectric conversion efficiencies. 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.

[0064] One embodiment of this application provides a solar cell, including a first electrode layer, a composite perovskite layer, and a second electrode layer. The composite perovskite layer is located between the first electrode layer and the second electrode layer. The composite perovskite layer comprises a perovskite material and a passivation material. The passivation material comprises a heterocyclic compound, wherein the heterocyclic atom of the heterocyclic compound includes at least N, and the heterocyclic compound further includes one or more substituents R located on the heterocycle. 1 R 1 Each independently includes an active group R. 2 The active group R 2 It includes one or more of the following: amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

[0065] In the aforementioned solar cell of this application, a passivation material is used to passivate the composite perovskite layer. This passivation material also contains heterocyclic compounds, wherein the heterocyclic atoms of the heterocyclic compounds include nitrogen (N) elements. The N elements possess lone pair electrons that can coordinate with the B-site metal of the perovskite layer. One or more substituents R on the heterocyclic compounds... 1 Contains a specific type of active group R 2 active group R 2It can interact with the perovskite layer to passivate defects or inhibit ion migration. In this way, the synergistic effect of heterocycles and substituents can effectively passivate defects on the surface of the perovskite layer, reduce non-radiative recombination at the perovskite layer interface, and help improve the photoelectric conversion efficiency and stability of solar cells.

[0066] In some embodiments, the composite perovskite layer comprises a mixture of perovskite material and passivation material; in other words, the perovskite material and passivation material are co-mixed in the same film layer. The passivation material, added as an additive to the perovskite layer, has a crystallization-regulating effect, thereby reducing bulk defects. This crystallization regulation can improve the crystallinity of the perovskite film, reduce the defect state density at grain boundaries, and thus improve the photoelectric conversion efficiency of the device.

[0067] The perovskite layer can be obtained by disassembling the battery. The perovskite layer is ultrasonically vibrated with a small amount of water, then concentrated to remove the water. After the solid is dried, a sample is taken and dissolved in methanol. The structure of the material is determined by liquid chromatography-mass spectrometry (GC-MS), and the structure of the passivation material can be obtained.

[0068] In some embodiments, the composite perovskite layer includes a perovskite bulk layer and a passivation layer. The perovskite bulk layer is located between a first electrode layer and a second electrode layer, and the passivation layer is disposed between the perovskite bulk layer and the second electrode layer. The perovskite bulk layer includes the perovskite material, and the passivation layer includes the passivation material. The passivation layer passivates the surface of the perovskite bulk layer, reducing the defect state density at the interface, thereby improving the photoelectric conversion efficiency of the device. Specifically, the passivation layer is disposed on the surface of the perovskite bulk layer facing the second electrode. Further, the thickness of the passivation layer is 0.1 nm to 20 nm. In some examples, the thickness of the passivation layer is 0.1 nm to 10 nm, or 0.1 nm to 5 nm. As an example, the thickness of the passivation layer can be 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, 20 nm, or any two of these values.

[0069] Two-dimensional maps of the mixed elemental distribution in the perovskite layer's interface passivation layer can be obtained using SEM-EDS (Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy) and EELS (Electron Energy Loss Spectroscopy). Further analysis of the elemental distribution within the passivation layer can be achieved by combining this with other techniques such as APT (Atomic Probe Tomography) or SIMS (Secondary Ion Mass Spectrometry). Additionally, liquid chromatography-mass spectrometry can be used to determine the type and content of the passivation layer material by detecting the unique mass-to-charge ratios of different compound molecules.

[0070] Understandably, the amino group includes, but is not limited to, one or more of the amino (primary amino), secondary amino, and tertiary amino groups. Amino salts refer to salts formed by the protonation of an amino group, and include, but are not limited to, one or more of the amino hydroiodide, hydrobromide, and hydrochloride salts.

[0071] Amine halides can be prepared by reacting the corresponding amine compound with a solution of the corresponding hydrohalic acid. For example, amine-containing heterocyclic compounds react with hydroiodic acid to form amine hydroiodates. Others are prepared similarly.

[0072] An example of the reaction of an amino compound with hydroiodic acid to form an amino hydroiodate: Take a clean, dry round-bottom flask, add a magnetic stir bar, then add an amino-containing heterocyclic compound (1 eq) and an appropriate amount of anhydrous ethanol. Place the flask in an ice-water bath and stir for 5 minutes to ensure thorough dispersion. Then, add an aqueous solution of hydroiodic acid (57% wt, 1.2 eq). After the addition is complete, continue stirring in the ice-water bath for 3 hours. Once the reaction is complete, remove the flask and allow it to stand at room temperature. Remove excess solvent by rotary evaporation. Wash repeatedly with diethyl ether until the product is white. Recrystallize the product in ethanol to obtain white crystals. Filter to remove excess mother liquor. Place the solid in an oven and vacuum dry for 12 hours to obtain the target product. The yield is not important in this process; obtaining a pure target product is sufficient.

[0073] Understandably, the organic acid groups and their salts include one or more of the following: phosphonic acid groups -PO(OH)2, phosphonophosphonic acid groups -POR3(OH), sulfonic acid groups -SO3H, sulfinic acid groups -SO2H, carboxylic acid groups -COOH, boric acid groups, and silicate groups. The salt groups of organic acid groups refer to the groups formed by organic acid groups and cations, where cations include, but are not limited to, metal cations and organic cations. For example, metal cations can be one or more of sodium ions and potassium ions, and organic cations can be ammonium ions. Organic acid groups and their salts can effectively passivate defects by forming coordination bonds with uncoordinated lead ions and other B-site defects on the perovskite surface. Furthermore, carboxyl groups can form hydrogen bonds with iodine, inhibiting iodine migration.

[0074] The passivation mechanisms of mercapto, alkylthio, alkoxy, and cyano groups have similarities and differences.

[0075] Taking the interaction between thiol groups and perovskite surface defects as an example, the mechanism of thiol passivation of perovskites mainly involves the interaction between thiol groups (-SH) and perovskite surface defects. For instance, the sulfur atom in the thiol group has a lone pair of electrons, which can interact with uncoordinated Pb atoms. 2+ When B-site ions form coordination bonds, they fill halogen vacancies, thereby reducing the defect state density and improving the photoelectric performance of the material. In addition, the thiol passivation layer can block the penetration of moisture and oxygen, reduce the degradation of perovskite materials, and improve the stability of devices in humid and high-temperature environments.

[0076] The mechanism of alkylthio-passivation of perovskites is similar to that of mercapto-passivation, mainly through the interaction between the alkylthio group and surface defects of the perovskite, reducing the defect state density and improving photoelectric properties and stability. Furthermore, the alkyl chain in the alkylthio group is hydrophobic, forming a hydrophobic layer on the perovskite surface, further preventing moisture intrusion and enhancing the material's environmental stability.

[0077] The passivation mechanisms of alkoxy and alkylthio groups on perovskites are similar. On the one hand, they can reduce the surface defect state density, suppress nonradiative recombination of charge carriers, and improve transport efficiency. On the other hand, they can react with uncoordinated Pb. 2+ The formation of stable Pb-O bonds by B-site ions enhances interfacial stability. Furthermore, the alkoxy and alkylthio group passivation layers can form a hydrophobic layer, preventing moisture intrusion.

[0078] The cyanate group can react with uncoordinated Pb 2+ When B-site ions form coordination bonds, defects are passivated, reducing the defect state density of perovskite. They can also form stable Pb-N bonds, enhancing interfacial stability. Furthermore, the carbon-nitrogen triple bond (C≡N) in the cyano group has strong electronegativity, enabling it to form strong coordination bonds with defect sites on the perovskite surface, further enhancing the passivation effect.

[0079] The carbonyl group in amide compounds can react with metal ions (such as Pb) in perovskites. 2+ This forms strong coordination bonds, effectively reducing surface defects in perovskites. This coordination effect lowers the defect density at the surface and grain boundaries of perovskite films, thereby reducing carrier recombination and improving device performance. Furthermore, the NH bonds in amide compounds have a strong resonance effect, resisting deprotonation and thus improving the thermal stability of the perovskite surface passivation layer.

[0080] In some of these embodiments, at least one R 1 The active group R in 2 It includes at least one of an amino group and its amine salt. The amino group can provide lone pair electrons to bind with uncoordinated lead ions, thereby passivating defects. This effect can reduce nonradiative charge recombination and improve carrier lifetime. In addition, it can provide hydrogen bonding, enhancing the bonding force between the molecule and the perovskite surface and improving stability.

[0081] In some embodiments, the heterocyclic compound includes a plurality of substituents R located on the heterocycle. 1 There are at least two Rs 1 The active group R in 2 The types are different. Thus, two different types of active groups R... 2 Heterocyclic compounds can provide more diverse active sites, improving the passivation effect on perovskite layers. These compounds are used to modify the perovskite film interface, with multiple active sites corresponding to undercoordinated Pb sites on the perovskite film surface or grain boundaries.2+ Sn 2+ Halide vacancies (such as I) - ,Br - Strong chemical interactions between defects can repair surface and grain boundary defects in perovskite films.

[0082] Furthermore, at least one R 1 The active group R in 2 Includes amino groups, such as amino groups. Further, at least one R 1 The active group R in 2 When an amino group is included, at least one other R 1 The active group R in 2 It includes one or more of the following: mercapto, alkylthio, alkoxy, cyano, amide, halogen, organic acid groups and their salts.

[0083] In some of these embodiments, at least one R 1 The active group R in 2 This includes various groups such as amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups, and their salts. Through an R... 1 The active group R in 2 It can provide more different active sites, and can passivate both deep and shallow level defects in perovskite films at the same time, thus improving the passivation effect on the perovskite layer.

[0084] Heterocyclic atoms and substituents R in heterocyclic compounds 1 The active group R in 2 All of these can serve as passivation active sites, simultaneously passivating various defects on the perovskite surface, reducing carrier recombination centers caused by positive charge defects and reverse built-in electric fields caused by negative charge defects at the upper interface, improving the open-circuit voltage and fill factor of the device, and thus helping to improve the photoelectric conversion efficiency of solar cells.

[0085] Furthermore, at least one R 1 The active group R in 2 This includes one or more of the following groups: mercapto, alkylthio, alkoxy, cyano, amide, halogen, organic acid groups and their salts, as well as combinations of amine groups. As an example, at least one R... 1 The active group R in 2 This includes combinations of cyanate and amino groups, such as -NH-CN. These combinations can simultaneously passivate cations (such as Pb) on the perovskite surface. 2+ ) and anions (such as I) - (Defects) to achieve more comprehensive defect repair.

[0086] Understandably, heterocyclic compounds may contain only one substituent R. 1Furthermore, the R 1 The active group R in 2 This includes various groups such as amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups, and their salts. It is understood that heterocyclic compounds can contain more than two substituents R. 1 Furthermore, one of the R 1 The active group R in 2 Including amine groups, such as amino groups; furthermore, where another R 1 The active group R in 2 It includes one or more of the following: mercapto, alkylthio, alkoxy, cyano, amide, halogen, organic acid groups and their salts.

[0087] Understandably, in some examples, R 1 The active group R 2 In other examples, R 1 In addition to containing the active group R 2 It may also include a linking group, such as an active group R 2 The group attached to the heterocycle includes, but is not limited to, one or more combinations of heterocyclic groups containing 3 to 30 cyclic atoms, aryl groups containing 6 to 30 cyclic atoms, heteroaryl groups containing 5 to 30 cyclic atoms, and alkyl groups.

[0088] Furthermore, the substituent R 1 The alkyl group can be a C1 to C6 alkyl group. Further, R 1 The alkyl group in the alkylthio group and alkoxy group can be a C1 to C6 alkyl group.

[0089] As an example, replacing the base R 1 It can be -HS, NH2, -Br, -C(=O)NH2, -CN, -OCH3 or -NH-CN.

[0090] As an example, replacing the base R 2 It can be -HS, NH2, -Br, -C(=O)NH2, -CN, -OCH3 or -NH-CN.

[0091] Furthermore, in heterocyclic compounds, the substituent R 1 It is attached to a carbon atom of the heterocyclic ring. Furthermore, in heterocyclic compounds, the substituent R... 1 The number is two or more, for example, two or three. Furthermore, in heterocyclic compounds, multiple substituents R... 1 The types can be the same or different, or different, thus providing more passivation active sites, which can passivate multiple defects on the perovskite surface at the same time.

[0092] In some embodiments, the heterocyclic atoms of the heterocyclic compound may contain only nitrogen (N). In other embodiments, in addition to N, the heterocyclic atoms of the heterocyclic compound may also include one or both of oxygen (O) and sulfur (S). Heterocyclic compounds containing multiple heterocyclic atoms can provide multiple passivation active sites, thereby improving the passivation effect.

[0093] As an example, the heterocyclic atom includes N. As an example, the heterocyclic atom includes N and O, or the heterocyclic atom includes N and S. Furthermore, the number of heterocyclic atoms N in the heterocyclic compound can be one or two.

[0094] In some embodiments, the heterocyclic compounds include aromatic heterocyclic compounds; the aromatic ring (such as a benzene ring) can bind to the perovskite surface through π-π interactions or electrostatic interactions, reducing X-site-related defects such as neutral iodine. Further, the heterocycles in the heterocyclic compounds have 5 to 6 ring atoms.

[0095] Furthermore, the heterocycles in the heterocyclic compounds include one or more of the following: thiadiazole ring, thiazolium ring, oxadiazole ring, imidazole ring, and pyridine ring. The pyridine group has a strong anchoring ability, enabling the passivation layer to bond tightly to the perovskite layer, thereby significantly reducing electron-hole interactions.

[0096] Optionally, the heterocyclic compound includes one or more of thiadiazole compounds, thiazolium compounds, oxadiazole compounds, imidazole compounds, and pyridine compounds.

[0097] As a non-limiting example, heterocyclic compounds include one or more of 2,5-dimercaptothiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 2-amino-5-mercapto-1,3,4-thiadiazole, 5-amino-1,2,3-thiadiazole, 4-methoxypyridinecarboxamide, amitevir, 1,3,4-oxadiazole-2,5-diamine (CAS No.: 2937-79-3), 1,3,4-oxadiazole-2,5-diamine hydroiodate, 5-cyanothiazole (CAS No.: 925742-12-5), and 7-bromo-1H-benzimidazole-5-amine (CAS No.: 177843-73-1).

[0098] The structural formulas of some heterocyclic compounds are as follows:

[0099] 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.

[0100] In some embodiments, the solar cell further includes a first charge transport layer disposed between the passivation layer and the second electrode layer, the first charge transport layer facilitating the extraction and transport of electrons or holes generated in the perovskite layer to the second electrode.

[0101] In some embodiments, the solar cell further includes a second charge transport layer disposed between the first electrode layer and the composite perovskite layer. The second charge transport layer facilitates the extraction and transport of electrons or holes generated in the perovskite layer to the first electrode. When both the first and second charge transport layers are present, one is an electron transport layer and the other is a hole transport layer. The electron transport layer functions to transport electrons generated by excitation in the perovskite layer to adjacent electrodes and blocks the transport of holes. The hole transport layer can extract and transport hole carriers and can block the passage of free electrons.

[0102] Furthermore, the first charge transport layer is an electron transport layer. Furthermore, the second charge transport layer is a hole transport layer.

[0103] 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) 71 At 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 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.

[0104] Optionally, the electron transport layer includes fullerenes and their derivatives.

[0105] Furthermore, the thickness of the electron transport layer is 5nm to 100nm. For example, the thickness of the electron transport layer can be 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm, etc., or a range of any two of the above values, such as 5nm to 30nm, 30nm to 50nm, 40nm to 80nm, 60nm to 100nm, etc.

[0106] 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, triphenylamine with a triphenylene core, 3, 4-Ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobisfluorene, polythiophene, phosphate monomers or polymers, carbazole monomers or polymers, sulfonic acid monomers or polymers, triphenylamine monomers or polymers, aromatic monomers, metal oxides (which may be referred to as first metal oxides), 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.

[0107] Furthermore, the thickness of the hole transport layer is 1 nm to 100 nm. For example, the thickness of the hole transport layer can be 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc., or a range of any two of the above values, such as 1 to 10 nm, 10 nm to 30 nm, 30 nm to 50 nm, 40 nm to 80 nm, 60 nm to 100 nm, etc.

[0108] 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 bulk layer 14, a passivation layer 15, a first charge transport layer 16, and a second electrode layer 17 stacked together. The perovskite bulk layer 14 and the passivation layer 15 constitute a composite perovskite layer.

[0109] 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. A 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, wherein the second charge transport layer 13 is a hole transport layer and the first charge transport layer 16 is an electron transport layer.

[0110] Understandably, in other examples, the second electrode layer 17 may also be disposed on the substrate, and accordingly, the solar cell is a formal cell.

[0111] 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). Further, the thickness of the transparent electrode is 10 nm to 1000 nm. For example, the thickness of the first electrode layer 101A can be 10nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm, 1000nm, etc., or a range of any two of the above values, such as 10nm~300nm, 300nm~500nm, 400nm~800nm, 600nm~1000nm, etc.

[0112] 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. Further, the thickness of the second electrode layer is 10 nm to 200 nm. For example, the thickness of the second electrode layer 104 can be 10nm, 30nm, 50nm, 80nm, 100nm, 140nm, 150nm, 200nm, etc., or a range of any two of the above values, such as 10nm~100nm, 100nm~150nm, 50nm~100nm, etc.

[0113] In some embodiments, the perovskite material has a crystal structure of 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.

[0114] 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.

[0115] Optionally, the B ion includes Pb. 2+ (lead ions), Sn 2+ (tin ion), Be2+ (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).

[0116] Optionally, the C ions include Cs + (cesium ion), Ag + (silver ions), K + (potassium ions) and Rb + One or more of (rubidium ions).

[0117] 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).

[0118] 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. - .

[0119] It is understood that the perovskite material in the aforementioned composite perovskite layer can be selected from Cs. x1FA 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.

[0120] 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.

[0121] Furthermore, the thickness of the composite perovskite layer or the perovskite bulk layer can be selected from conventional thicknesses in the art, such as 200 nm to 1000 nm. For example, the thickness of the perovskite layer can be 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, etc., or a range consisting of any two of the above values, such as 200 nm to 300 nm, 300 nm to 500 nm, 400 nm to 800 nm, 600 nm to 1000 nm, etc.

[0122] 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.

[0123] 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.

[0124] 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:

[0125] A first electrode layer, the aforementioned composite perovskite layer, and a second electrode layer are formed in a stacked configuration.

[0126] 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.

[0127] In some embodiments, the composite perovskite layer comprises a mixture of perovskite material and passivation material; forming the composite perovskite layer includes the following steps: mixing the passivation material containing a heterocyclic compound and a precursor for forming the perovskite to form a mixed solution, coating the mixed solution onto a substrate, such as a first electrode, and annealing to obtain the composite perovskite layer. Further, the mass content of the passivation material in the mixed solution is 0.1% to 5%, and examples include 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%, or within a range defined by any two point values ​​as endpoints, optionally from 0.2% to 1%.

[0128] In some embodiments, forming a composite perovskite layer includes the following steps: forming a perovskite bulk layer; applying a passivation solution containing the heterocyclic compound onto the perovskite bulk layer; and annealing to obtain a passivation layer.

[0129] Furthermore, the coating method includes, but is not limited to, any one of the following: spin coating, spray coating, blade coating, and slot coating.

[0130] Furthermore, the annealing temperature described above is all between 80℃ and 150℃. Furthermore, the annealing time described above is all between 1 min and 30 min. As an example, the annealing temperature can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 145℃, 140℃, 155℃, 150℃, or any two of the above values, and can be selected as 100℃ to 120℃. 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, 15 min, 20 min, 25 min, 30 min, or any two of the above values, and can be selected as 5 min to 15 min.

[0131] Optionally, the concentration of the heterocyclic compound in the passivation solution is 0.05 mg / mL to 10 mg / mL; as an example, it can be 0.05 mg / mL, 0.1 mg / mL, 0.15 mg / mL, 0.2 mg / mL, 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, 1 mg / mL, 2 mg / mL, 5 mg / mL, 10 mg / mL, or any two of the above values, and can be selected as 0.2 to 5 mg / mL or 0.25 to 5 mg / mL, more preferably 0.25 mg / mL to 2 mg / mL.

[0132] In some examples, the material of the perovskite layer includes a perovskite-type metal halide with the chemical formula ABX3. The preparation method of the perovskite 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 layer.

[0133] 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).

[0134] Other embodiments of this application provide a photovoltaic module, including the solar cell as described above.

[0135] The aforementioned solar cells have high light conversion efficiency and good stability, which can improve the efficiency of photovoltaic modules.

[0136] 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).

[0137] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a backsheet.

[0138] 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.

[0139] 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.

[0140] 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).

[0141] Furthermore, the aforementioned photovoltaic modules also include junction boxes and outer frames.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] In some embodiments, the photovoltaic module is a solar panel.

[0146] According to one embodiment of this application, a photovoltaic system is also provided, including the photovoltaic module described above.

[0147] 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.

[0148] 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.

[0149] The aforementioned photovoltaic system can be a stand-alone photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0150] 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.

[0151] 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.

[0152] The two photovoltaic power generation systems mentioned above each have their own characteristics and can be selected according to the specific application scenario.

[0153] Other embodiments of this application provide an electrical device, including a solar cell as described above or a photovoltaic module as described above.

[0154] Other embodiments of this application provide a power generation device, including a solar cell as described above or a photovoltaic module as described above.

[0155] 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.

[0156] 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.

[0157] As another implementation method, the power supply device can be a wearable device, such as a watch.

[0158] 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.

[0159] 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.

[0160] Example 1

[0161] A method for fabricating a solar cell device is as follows:

[0162] 1) Fabrication of FTO conductive glass (including the first electrode layer with substrate): Dimensions are 2.0*2.0cm. 2 The FTO glass was laser-etched to remove 0.35 cm of FTO from each end, exposing the glass substrate. The etched FTO conductive glass was then ultrasonically cleaned several times with water, acetone, and isopropanol, and then dried with nitrogen for later use.

[0163] 2) Preparation of hole transport layer: FTO was treated with ultraviolet ozone. 100 μL of PEDOT:PSS solution 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 20 nm.

[0164] 3) Preparation of the perovskite layer: The perovskite bulk layer was prepared using a one-step method. 496.32 mg of formamidinium hydroiodate (FAI), 2.05 mg of methylamine iodide (MAI), 4.87 mg of methylammonium bromide (MABr), 40.27 mg of cesium iodide (CsI), 25.69 mg of lead bromide (PbBr2), and 1396.86 mg of lead iodide (PbI2) were dissolved in 2 mL of a mixture of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (DMF to DMSO volume ratio 4:1) to obtain the perovskite precursor solution. A perovskite precursor solution was spin-coated onto the prepared hole transport layer at 4000 rpm for 30 s. Approximately 10 s after the spin-coating began, 400 μL of the antisolvent anisole was added dropwise. The film was then placed on a hot plate and annealed at 110 °C for 60 min to obtain a perovskite layer with a thickness of 800 nm. 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.98 Br 0.02 3.

[0165] 4) Preparation of the passivation layer:

[0166] A solution of 0.25 mg / mL 2,5-dimercaptothiadiazole (a heterocyclic compound) in isopropanol (passivation solution A) was spin-coated onto a perovskite layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a thiadiazole compound passivation layer.

[0167] 5) Preparation of electron transport layer / hole blocking layer: The thin film with the prepared perovskite 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.

[0168] 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.

[0169] 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.

[0170] The perovskite solar cell obtained through the above steps is labeled as cell 1.

[0171] Examples 2-6

[0172] The process is basically the same as in Example 1, except that the preparation steps of the passivation layer are different. Specifically, the types of passivation materials (heterocyclic compounds) in the passivation solution are different, but the concentrations are the same, as shown in the table below.

[0173] Examples 7-8

[0174] The process is basically the same as in Example 6, except that the preparation steps of the passivation layer are different. Specifically, the types of passivation materials (heterocyclic compounds) in the passivation solution are the same, but the concentrations are different, as shown in the table below.

[0175] Example 9

[0176] The method is basically the same as in Example 1, except that the passivation layer preparation step is omitted, and 0.5 wt% (calculated based on the total mass of the perovskite precursor solution) of 2,5-dimercaptothiadiazole is added to the perovskite precursor solution as an additive to directly prepare the perovskite layer.

[0177] Examples 10-13

[0178] The method is basically the same as in Example 1, except that the preparation steps of the passivation layer are different. Specifically, the types of passivation materials (heterocyclic compounds) in the passivation solution are different, but the concentrations are the same, as shown in the table below.

[0179] The 1,3,4-oxadiazole-2,5-diamine hydroiodate used in Example 11 was prepared as follows: A clean, dry round-bottom flask was filled with 1 mole of 1,3,4-oxadiazole-2,5-diamine and an appropriate amount of ethanol to completely dissolve it. The flask was then placed in an ice-water bath and stirred. 1.2 molar equivalents of hydroiodic acid were added dropwise, and the reaction continued for 3 hours. After the reaction was complete, excess solvent was removed by rotary evaporation, and the product was washed with diethyl ether. Excess solvent was removed by filtration, and the resulting salt solid was dried under vacuum at 40°C for 12 hours. After drying, the product was collected, weighed, and packaged.

[0180] Comparative Example 1

[0181] It is basically the same as Example 1, except that the passivation layer preparation step is omitted.

[0182] Comparative Example 2

[0183] The process is basically the same as in Example 1, except that the preparation steps of the passivation layer are different. Specifically, the types of passivation materials in the passivation solution are different, but the concentrations are the same, as shown in the table below.

[0184] The following are performance tests.

[0185] (1) Photovoltaic conversion efficiency performance test. Under normal temperature and pressure, a standard light source with AM1.5G as the simulated solar light source was used for testing in accordance with the national standard IEC61215. The intensity of the light was corrected using a crystalline silicon solar cell to reach the intensity of a solar cell. The current-voltage characteristic curve of the solar cell 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 cell were obtained.

[0186] 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 .

[0187] Among them, P in P out V mpp J mpp V oc J sc FF 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.

[0188] (2) Photothermal stability T80 test method:

[0189] The solar cell was placed in a nitrogen atmosphere at 75°C with an intensity of 100 mw / cm². 2 Irradiation by light-emitting diodes (LEDs) and other sources is used to track the change of the maximum power point of the solar cell as the solar cell operates. The time required for the efficiency of the maximum power point to decay to 80% of the initial efficiency is recorded as T80. The magnitude of this parameter indicates the photothermal stability of the solar cell.

[0190] The following table shows some parameters and performance results of the solar cells in each embodiment and comparative example.

[0191] Table 1

[0192] As shown in the table above, Comparative Example 1 did not use a passivation layer, and Comparative Example 2 used phenylethylamine iodine passivation; the photoelectric conversion efficiency of the solar cells prepared by both examples was relatively low. In this application, specific types of heterocyclic compounds are used to form the passivation layer, resulting in improved photoelectric conversion efficiency and stability of the prepared solar cells.

[0193] 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.

[0194] 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 composite perovskite layer, and a second electrode layer, wherein the composite perovskite layer is located between the first electrode layer and the second electrode layer, the composite perovskite layer comprising a perovskite material and a passivation material, the passivation material comprising a heterocyclic compound, wherein the heterocyclic atom of the heterocyclic compound comprises at least N, and the heterocyclic compound further comprises one or more substituents R located on the heterocycle. 1 R 1 Each independently includes an active group R. 2 The active group R 2 It includes one or more of the following: amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

2. The solar cell of claim 1, wherein, It meets one or more of the following characteristics: (1) The heterocyclic compound includes multiple substituents R located on the heterocycle. 1 There are at least two Rs 1 The active group R in 2 Different types; (2) At least one R 1 The active group R in 2 This includes various groups such as amine groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

3. The solar cell of claim 1 or 2, wherein, At least one R 1 The active group R in 2 It includes one or more of the amino group and its amine salt.

4. The solar cell according to any one of claims 1 to 3, wherein, At least one R 1 The active group R in 2 Including one or more of mercapto, alkylthio, alkoxy, cyano, amide, halogen, organic acid groups and their salts, and one or more of amine groups and their amine salts; optionally, at least one R 1 The active group R in 2 Combinations of cyanate and amino groups are included, and -NH-CN is also an option.

5. The solar cell as claimed in any one of claims 1 to 4, 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; (3) The heterocyclic atoms of the heterocyclic compounds also include one or both of O and S.

6. The solar cell as claimed in any one of claims 1 to 5, wherein, The heterocyclic compounds contain one or more of the following: thiadiazole ring, thiazolium ring, oxadiazole ring, imidazole ring, and pyridine ring.

7. The solar cell as claimed in any one of claims 1 to 6, wherein, The heterocyclic compounds include one or more of the following: 2,5-dimercaptothiadiazole, 2-amino-5-bromo-1,3,4-thiadiazole, 2-amino-5-mercapto-1,3,4-thiadiazole, 5-amino-1,2,3-thiadiazole, 4-methoxypyridinecarboxamide, amitevir, 1,3,4-oxadiazole-2,5-diamine, 1,3,4-oxadiazole-2,5-diamine hydroiodate, 5-cyanothiazole, and 7-bromo-1H-benzimidazole-5-amine.

8. The solar cell as claimed in any one of claims 1 to 7, wherein, The composite perovskite layer comprises a mixture of perovskite materials and passivation materials. Alternatively, the composite perovskite layer includes a perovskite body layer and a passivation layer, wherein the perovskite body layer is located between the first electrode layer and the second electrode layer, and the passivation layer is disposed between the perovskite body layer and the second electrode layer. The perovskite body layer includes the perovskite material, and the passivation layer includes the passivation material. Optionally, the thickness of the passivation layer is 0.1 nm to 20 nm.

9. The solar cell as claimed in any one of claims 1 to 8, 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 composite perovskite layer and the second electrode layer; 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 layer and the composite perovskite layer; optionally, the second charge transport layer is a hole transport layer.

10. The solar cell as claimed in any one of claims 1 to 9, wherein, The first electrode layer is a transparent electrode.

11. A method for preparing a solar cell, comprising the following steps: A first electrode layer, a composite perovskite layer, and a second electrode layer are formed in a stacked configuration. wherein, The composite perovskite layer comprises a perovskite material and a passivation material. The passivation material comprises a heterocyclic compound, wherein the heterocyclic atom of the heterocyclic compound includes at least N, and the heterocyclic compound further comprises one or more substituents R located on the heterocycle. 1 R 1 Each independently includes an active group R. 2 The active group R 2 It includes one or more of the following: amino groups and their amine salts, mercapto groups, alkylthio groups, alkoxy groups, cyano groups, amide groups, halogens, organic acid groups and their salts.

12. The production method according to claim 11, wherein The formation of the composite perovskite layer includes the following steps: Formation of the perovskite bulk layer; A passivation solution containing the heterocyclic compound was coated onto the perovskite bulk layer, and then annealed to obtain the passivation layer. Optionally, the concentration of the heterocyclic compound in the passivation solution is 0.05 mg / mL to 10 mg / mL, and optionally 0.2 mg / mL to 5 mg / mL; Optionally, the annealing treatment is performed at a temperature of 80°C to 150°C for a time of 1 min to 30 min.

13. A photovoltaic module comprising a solar cell according to any one of claims 1 to 10 or a solar cell prepared by the preparation method according to any one of claims 11 to 12.

14. An electrical device comprising a solar cell according to any one of claims 1 to 10, a solar cell prepared by the preparation method according to any one of claims 11 to 12, or a photovoltaic module according to claim 13.

15. A power generation device comprising a solar cell according to any one of claims 1 to 10, a solar cell prepared by the preparation method according to any one of claims 11 to 12, or a photovoltaic module according to claim 13.

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