Perovskite thin film, preparation method thereof and perovskite battery

Abstract

The invention provides a perovskite thin film, a preparation method thereof and a perovskite battery. Materials of the perovskite thin film comprise a perovskite material and an additive. In addition, heterocycle, sulfonyl and other structures contained in the structure of the additive can form multi-element interaction with ions in the perovskite material, nucleation energy barriers of an alpha phase are reduced, generation of a delta phase is inhibited, and therefore the photoelectric conversion efficiency and stability of the cell are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite film and a preparation method thereof, as well as a perovskite cell. Background Art

[0002] Perovskite solar cells, as a new third-generation solar cell, offer excellent properties such as low cost, solution processing, tunable bandgap, low exciton binding energy, high absorption coefficient, and long carrier diffusion length and lifetime. They have attracted extensive research and are developing rapidly. Perovskite thin films based on perovskite materials are a key component of perovskite solar cells.

[0003] Because the non-perovskite yellow δ phase (hexagonal phase) has good thermodynamic stability, at present, when preparing perovskite films, it is easy to generate an intermediate phase - δ phase, rather than the photoactive black α phase (cubic phase), which affects the photoelectric conversion efficiency of perovskite cells. Summary of the Invention

[0004] In view of the technical problems existing in the background technology, the present application provides a perovskite film and a preparation method thereof, as well as a perovskite battery, which can catalyze the generation of α phase and improve the photoelectric conversion efficiency of the battery.

[0005] In a first aspect, an embodiment of the present application provides a perovskite film, wherein the material of the perovskite film includes a perovskite material and an additive, wherein the additive includes at least one compound having a structure represented by formula (I):

[0006] wherein Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each occurrence of the heteroatoms is independently selected from N or O; Ring B or ring C are each independently selected from a benzene ring, a single heterocycle, a C6~C 18 Any of the fused aromatic rings; L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 a combination of one or more of alkylene groups; The substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group, amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1.

[0007] Optionally, in some embodiments of the present application, the general structural formula of the perovskite material is ABX3, wherein A is Cs + , Rb + 、[CH3N=NH] + 、CH3(CH2) n-2 NH3 + 、[NH3(CH2) n NH3] 2+ At least one of n≥2, B is a divalent metal cation selected from Pb 2+ 、Sn 2+ 、Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ 、Mn 2+ 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ At least one of, X is selected from Cl - Br - , I - At least one of .

[0008] Optionally, in some embodiments of the present application, the additive includes at least one of celecoxib, etoricoxib, rofecoxib, parecoxib, etoricoxib, and valdecoxib.

[0009] Optionally, in some embodiments of the present application, the perovskite film is a single-layer film or a composite film; the material of the single-layer film is a mixture of the perovskite material and the additive; the composite film includes a perovskite layer and a modified layer, and the modified layer includes one or two layers of a first film layer and a second film layer respectively stacked on two opposite sides of the perovskite layer, wherein the material of the perovskite layer includes the perovskite material, and the materials of the first film layer and the second film layer each independently include the additive.

[0010] Optionally, in some embodiments of the present application, in the single-layer film, the molar ratio of the additive to the perovskite material is 0.01~0.1:100.

[0011] Optionally, in some embodiments of the present application, the thickness of the single-layer film is 400~900nm.

[0012] Optionally, in some embodiments of the present application, the composite film satisfies at least one of the following conditions: (1) The thickness of the perovskite layer is 300-600 nm; (2) The thickness of the first film layer is 1-100 nm; (3) the thickness of the second film layer is 1 to 100 nm; and (4) The total thickness of the perovskite layer and the modified layer is 300-800 nm.

[0013] In a second aspect, an embodiment of the present application provides a method for preparing a perovskite thin film, comprising: depositing a material for a perovskite thin film to obtain a perovskite thin film; The material of the perovskite film includes a perovskite material and an additive, wherein the additive includes at least one compound having a structure represented by formula (I):

[0014] wherein Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each occurrence of the heteroatoms is independently selected from N or O; Ring B or ring C are each independently selected from a benzene ring, a single heterocycle, a C6~C 18 Any of the fused aromatic rings; L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 a combination of one or more of alkylene groups; The substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group, amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1.

[0015] Optionally, in some embodiments of the present application, the step of depositing a material for a perovskite film to obtain the perovskite film includes: mixing the perovskite material, the additive and a first solvent to obtain a mixed solution; depositing the mixed solution and performing a first annealing treatment to obtain a perovskite film; Wherein, the first solvent comprises one or more of isopropyl alcohol, chlorobenzene, toluene, ethyl acetate, N,N-dimethylformamide, dimethyl sulfoxide, 2-methoxyethanol and N-methylpyrrolidone; In the mixed solution, the molar ratio of the additive to the perovskite material is 0.01-0.1:100; The temperature of the first annealing treatment is 90-110° C., and the time of the first annealing treatment is 90-120 minutes.

[0016] Optionally, in some embodiments of the present application, the step of depositing a material for a perovskite film to obtain the perovskite film includes: Depositing an additive solution containing the additive, annealing at 80-90° C. for 10-20 minutes to obtain a first film layer, depositing a perovskite solution containing the perovskite material on one side of the first film layer, annealing at 90-110° C. for 90-120 minutes to obtain a perovskite layer, wherein the perovskite layer and the first film layer together constitute the perovskite thin film; or, Depositing a perovskite solution containing the perovskite material, annealing at 90-110° C. for 90-120 minutes to obtain a perovskite layer, depositing an additive solution containing the additive on one side of the perovskite layer, annealing at 100-120° C. for 15-30 minutes to obtain a second film layer, wherein the perovskite layer and the second film layer together constitute the perovskite thin film; or, The additives include a first additive and a second additive; a first solution containing the first additive is deposited, and the solution is annealed at 80-90° C. for 10-20 minutes to obtain a first film layer; a perovskite solution containing the perovskite material is deposited on one side of the first film layer, and the solution is annealed at 90-110° C. for 90-120 minutes to obtain a perovskite layer; a second solution containing the second additive is deposited on a side of the perovskite layer away from the first film layer, and the solution is annealed at 100-120° C. for 15-30 minutes to obtain a second film layer; the first film layer, the perovskite layer, and the second film layer together constitute the perovskite thin film.

[0017] In a third aspect, an embodiment of the present application provides a perovskite cell, comprising a first electrode, a photoactive layer, and a second electrode arranged in a stacked manner, wherein the photoactive layer comprises the perovskite film described above, or a perovskite film prepared by the preparation method described above.

[0018] Optionally, in some embodiments of the present application, the perovskite cell further includes a hole transport layer and an electron transport layer, the hole transport layer is arranged between the first electrode and the photoactive layer, and the electron transport layer is arranged between the second electrode and the photoactive layer.

[0019] In the technical solution provided in the present application, additives are added to the perovskite film. The heterocyclic rings, sulfonyl groups and other structures contained in the structure of the additives can form multi-component interactions with the ions in the perovskite material, reduce the nucleation energy barrier of the α phase, and inhibit the formation of the δ phase, thereby effectively improving the photoelectric conversion efficiency and stability of the battery; at the same time, these groups can also interact with the uncoordinated cation vacancies and anion vacancies at the grain boundaries, play a role in passivating grain boundary defects and improving the crystallization quality, thereby further improving the battery performance and stability.

[0020] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0022] Figure 1 This is a schematic structural diagram of the method for preparing a perovskite battery proposed in the first embodiment of the present application; Figure 2 This is a schematic structural diagram of a method for preparing a perovskite cell according to a second embodiment of the present application; Figure 3 This is a schematic structural diagram of a method for preparing a perovskite battery according to the third embodiment of the present application; Figure 4 is a graph showing the change in ultraviolet absorption intensity of the photoactive layers prepared in Example 1 and Comparative Example 1 over time during the annealing process; Figure 5 are SEM images of the photoactive layers prepared in Example 1 and Comparative Example 1; Figure 6 Statistical distribution diagram of Voc and PCE of the perovskite cells prepared in Examples 1 to 5 and Comparative Example 1; Figure 7 JV test diagrams of the perovskite cells prepared in Examples 6 to 8 and Comparative Example 2; Figure 8 JV test diagram of the perovskite battery in Example 9 and Comparative Example 3; Figure 9 JV test diagrams of the perovskite cells in Example 1 and Comparative Example 1; Figure 10Graph showing the thermal stability changes of the batteries of Example 1 and Comparative Example 1 at 85°C.

[0023] Description of reference numerals: DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0026] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a hard limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numbers within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0027] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0028] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0029] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0030] In the description of the embodiments of the present application, the term "at least one" refers to one or more, "multiple" refers to more than two (including two), similarly, "multiple groups" refers to more than two (including two), and "multiple pieces" refers to more than two (including two). "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0031] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0032] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0033] Perovskite materials, especially ABX3 organic-inorganic hybrid perovskites, are considered to be highly promising light-absorbing materials due to their suitable band gap and high thermal stability. They are widely used in the photoactive layer 3 of perovskite cells 100. However, ABX3 easily forms a thermodynamically stable non-perovskite yellow δ phase (hexagonal phase) at room temperature, rather than a photoactive black α phase (cubic phase), which significantly reduces the device efficiency and even continuously affects the stability of the device. In addition, polycrystalline perovskite films prepared by solution method generally have grain boundary defects (such as uncoordinated Pb 2+ , I - Vacancies) and large surface roughness aggravate non-radiative recombination, restricting Voc (open circuit voltage) and long-term stability.

[0034] In view of this, in a first aspect, the embodiments of the present application provide a perovskite film, such as Figures 1 to 3 As shown, the material of the perovskite film includes a perovskite material and an additive, and the additive includes at least one compound having a structure shown in formula (I):

[0035] Wherein, Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each heteroatom is independently selected from N or O. That is, when Ring A has multiple heteroatoms, the multiple heteroatoms may be the same or different; specifically, Ring A may be a furan ring, a pyrrole ring, an imidazole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a 2(5H)-furanone ring ( )、1H-pyrrole-2(5H)-one ring( ), pyridine ring, pyran ring, pyridazine ring, pyrimidine ring, pyrazine ring, etc.

[0036] Ring B or ring C are each independently selected from a benzene ring, a single heterocycle, a C6~C 18 In any one of the fused aromatic rings, ring B and ring C may be the same or different; it is understood that the single heterocyclic ring may be a five-membered heterocyclic ring or a six-membered heterocyclic ring, and the present application does not limit the type and number of heteroatoms in the single heterocyclic ring, which may specifically be a furan ring, a thiophene ring, a pyrrole ring, an imidazole ring, a pyrazole ring, a thiazole ring, an oxazole ring, an isoxazole ring, a 2(5H)-furanone ring ( )、1H-pyrrole-2(5H)-one ring( ), pyridine ring, pyran ring, pyridazine ring, pyrimidine ring, pyrazine ring, etc. C6~C 18 A fused aromatic ring refers to a structure having 6 to 18 carbon atoms, formed by the fusion of at least one benzene ring with other rings (including but not limited to aromatic rings, heteroaromatic rings, and saturated rings). Specifically, it may be naphthalene, phenanthrene, anthracene, tetraacene, benzofuran, dibenzofuran, indole, quinoline, isoquinoline, carbazole, and the like.

[0037] L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 A combination of one or more of alkylene groups. In the present application, "substituted" means that the hydrogen atom in the substituted group is replaced by a substituent. "Unsubstituted or substituted by a substituent" means that the defined group may be substituted by a substituent or not. And when the same substituent appears multiple times, it can be independently selected from different groups. If the general formula contains n1 R1, then R1 can be independently selected from different groups. In addition, in the present application, "alkyl" can mean a straight-chain alkyl or a branched-chain alkyl. The number of carbon atoms in the alkyl group can be 1-10, 1-8, 1-6, 1-5 or 1-4. An alkylene group is a group formed by losing a hydrogen atom on the basis of an alkyl group, C1~C 10 The alkylene group refers to an alkylene group having 1 to 10 carbon atoms.

[0038] The substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group (-F, -Cl, -Br or -I), amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 Any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1. R1, R2, and R3 may be the same or different. It is understood that in the present application, a halogen group may be -Cl, -Br, -F, or -I; an amino group may be -NR4R5; a nitro group refers to -NO2; a carboxyl group refers to -COOH; an aldehyde group refers to -CHO; an acyl group refers to -CO-R6; and an alkylamide group refers to -NH-CO-R7; wherein R4 and R5 are each independently selected from hydrogen, deuterium or an alkyl group, and R6 and R7 are each independently selected from an alkyl group. In addition, a plurality of combinations refers to a group formed by two or more groups connected or substituted with each other, for example, a combination of a halogen group and an alkyl group may be -CF3.

[0039] In the technical solution provided by the present application, additives are added to the perovskite film. The heterocyclic rings, sulfonyl groups and other structures contained in the additives can form multi-component interactions with the ions in the perovskite material (for example, with Pb in the FAPbI3 perovskite material). 2+ Coordination occurs, FA + Hydrogen bonding occurs, I - At the same time, these groups can also interact with uncoordinated cation vacancies and anion vacancies at the grain boundaries to passivate grain boundary defects and improve crystallization quality, thereby further improving battery performance and stability.

[0040] In summary, the perovskite film provided in this embodiment has high crystalline quality, low defect density and excellent stability. The perovskite cell 100 prepared using the perovskite film has better photoelectric conversion efficiency and stability.

[0041] In addition, the perovskite film provided in this embodiment does not require the introduction of additional doping elements or solvents, and can improve the film's crystallization quality and defects while avoiding the introduction of new problems such as material band gap widening and solvent residue.

[0042] In some embodiments, the number of heteroatoms in the ring A is 1 or 2, specifically selected from a pyrazole ring, an isoxazole ring, a 2(5H)-furanone ring, a 1H-pyrrol-2(5H)-one ring, and a pyridine ring; the ring B or the ring C are each independently selected from any one of a benzene ring, a pyridine ring, a naphthalene ring, a phenanthrene ring, and an anthracene ring; L is a single bond; R1, R2, and R3 are each independently selected from C1 to C 10 Alkyl, halogen, amino, C1~C 10 Alkylamide, C1~C 10 Any one of the halogenated alkyl groups; the connection site on ring B for connecting to the substituent -L-SO2-R3 is in the para position to the connection site on ring B for connecting to ring A. The compound based on the above characteristics is widely available, easy to obtain, and has good catalytic α-phase and passivation defect effects.

[0043] In some specific embodiments, the additive may include but is not limited to at least one of celecoxib (CAS: 169590-42-5, alias: 4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide), etoricoxib (CAS: 202409-33-4, alias: 5-chloro-3-[4-(methylsulfonyl)phenyl]-2-(2-methyl-5-pyridyl)pyridine), rofecoxib (CAS: 162011-90-7, alias: 4-[4-(methylsulfonyl)phenyl]-3-phenyl-2(5)H-furanone), parecoxib (CAS: 198470-84-7), erecoxib (CAS: 395683-14-4), and valdecoxib (CAS: 181695-72-7). The structural formula of the above compounds is as follows: .

[0044] In some embodiments, the general structural formula of the perovskite material is ABX3. The perovskite material of this configuration has a suitable band gap and thermal stability, and has a good effect as a light absorbing material. At the same time, this type of material is more likely to transform into the δ phase when preparing a film. The present application combines it with an additive to better inhibit the formation of this unfavorable intermediate phase, give full play to the good properties of the perovskite material itself, and obtain a perovskite film with better conversion efficiency and stability. Further, in some embodiments, in the ABX3, A is Cs + , Rb + 、[CH3N=NH] + 、CH3(CH2) n-2 NH3 + 、[NH3(CH2) n NH3] 2+ At least one of n≥2, B is a divalent metal cation selected from Pb 2+ 、Sn 2+ 、Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ 、Mn 2+ 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ At least one of, X is selected from Cl - Br - , I - At least one of .

[0045] There are several options for how the additives are distributed in the perovskite film.

[0046] In some embodiments, the additive is dispersed throughout the perovskite film in a substantially uniform distribution. Specifically, in this embodiment, the perovskite film is a single layer comprising a mixture of the perovskite material and the additive, with the perovskite material and the additive being uniformly distributed throughout the film. This ensures that the additive is in full contact with the perovskite material, interacting well with it, inhibiting the formation of the delta mesophase and passivating grain boundary defects.

[0047] Furthermore, in the single-layer film, the molar ratio of the additive to the perovskite material is 0.01~0.1:100; by controlling the molar ratio within this range, the effect of the additive can be fully exerted while taking into account the light absorption characteristics of the perovskite material itself, thereby comprehensively improving the PCE of the perovskite film.

[0048] In addition, the thickness of the single-layer film may be 400-900 nm; for example, it may be 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, or a value between any two of the above values.

[0049] In other embodiments, the additive is dispersed on one or both sides of the perovskite film, which can inhibit the formation of the delta intermediate phase of the perovskite material at the interface and passivate grain boundary defects. Specifically, in this embodiment, the perovskite film is a composite film, and the composite film is a laminated structure, which can specifically include a perovskite layer 31 and a modified layer, and the modified layer includes one or two layers of a first film layer 32 and a second film layer 33 respectively stacked on two opposite sides of the perovskite layer 31, wherein the material of the perovskite layer 31 includes the perovskite material, and the materials of the first film layer 32 and the second film layer 33 each independently include the additive. That is, the perovskite film can include a stacked perovskite layer 31 and a first film layer 32, or a stacked perovskite layer 31 and a second film layer 33, or a stacked first film layer 32, a perovskite layer 31 and a second film layer 33. When the perovskite film includes both the first film layer 32 and the second film layer 33, the additives contained in the two film layers can be the same or different.

[0050] In the composite film, the thickness of the perovskite layer 31 is 300-600 nm; for example, it can be 300 nm, 400 nm, 500 nm, 600 nm, or a value between any two of the above values. When the composite film includes a first film layer 32, the thickness of the first film layer 32 can be 1-100 nm; for example, 1 nm, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or a value between any two of the above values. When the composite film includes a second film layer 33, the thickness of the second film layer 33 can be 1-100 nm; for example, 1 nm, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or a value between any two of the above values. Regardless of whether the modified layer contains one or both of the first film layer 32 and the second film layer 33 , the total thickness of the perovskite layer 31 and the modified layer is 300-800 nm; for example, it can be 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, or a value between any two of the above values.

[0051] In a second aspect, the present application proposes a method for preparing a perovskite film, the preparation method comprising the following steps: S100, depositing materials for the perovskite film to obtain the perovskite film.

[0052] The material of the perovskite film includes a perovskite material and an additive, wherein the additive includes at least one compound having a structure represented by formula (I):

[0053] Wherein, Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each heteroatom is independently selected from N or O; Ring B or Ring C is independently selected from a benzene ring, a single heterocyclic ring, a C6~C 18 Any one of the fused aromatic rings; L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 One or more combinations of alkylene groups; the substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group, amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 Any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1.

[0054] In actual preparation, solution deposition can be performed using methods such as spin coating, printing, inkjet printing, doctor blade coating, printing, dip coating, immersion coating, spray coating, roll coating, casting, slot coating, and strip coating, etc. This application does not impose any restrictions on this.

[0055] When the perovskite film to be prepared is a single-layer film, step S100 may specifically include: S10a, mixing the perovskite material, the additive, and a first solvent to obtain a mixed solution; S20a, depositing the mixed solution and performing a first annealing treatment to obtain a perovskite film.

[0056] The general structural formula of the perovskite material is ABX3, where A is Cs + , Rb + 、[CH3N=NH] + 、CH3(CH2) n-2 NH3 + 、[NH3(CH2) n NH3] 2+ At least one of n≥2, B is a divalent metal cation selected from Pb 2+ 、Sn 2+ 、Cu 2 + 、Ni 2+ 、Cd 2+ Cr 2+ 、Mn2+ 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ At least one of, X is selected from Cl - Br - , I - At least one of .

[0057] Wherein, the additive includes at least one of celecoxib, etoricoxib, rofecoxib, parecoxib, etoricoxib and valdecoxib.

[0058] The first solvent includes one or more of isopropyl alcohol (IPA), chlorobenzene (CBZ), toluene, ethyl acetate (EA), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 2-methoxyethanol (2-ME) and N-methylpyrrolidone (NMP).

[0059] In the mixed solution, the molar ratio of the additive to the perovskite material is 0.01 to 0.1:100, for example, 0.01:100, 0.02:100, 0.03:100, 0.04:100, 0.05:100, 0.06:100, 0.07:100, 0.08:100, 0.09:100, 0.1:100, and any values ​​between any two of the foregoing values. Controlling the molar ratio within this range can regulate the ratio of the additive to the perovskite material in the film, fully utilizing the additive's effect while also taking into account the light absorption properties of the perovskite material itself, thereby comprehensively improving the PCE of the perovskite film.

[0060] In some embodiments, the concentration of the additive in the mixed solution may be 0.01-50 mmol / L.

[0061] The temperature of the first annealing treatment is 90-110°C, and the time of the first annealing treatment is 90-120 minutes. After the first annealing treatment, the perovskite thin film is solidified and the film formation effect can be greatly improved.

[0062] When the perovskite thin film to be prepared is a composite film, and the composite film includes a stacked first film layer 32 and a perovskite layer 31, step S100 may specifically include: S10b, depositing an additive solution containing the additive, annealing at 80-90°C for 10-20 minutes to obtain a first film layer 32, depositing a perovskite solution containing the perovskite material on one side of the first film layer 32, annealing at 90-110°C for 90-120 minutes to obtain a perovskite layer 31, the perovskite layer 31 and the first film layer 32 together constitute the perovskite thin film.

[0063] In some embodiments, the additive solution further includes a second solvent, which may include, but is not limited to, one or more of isopropyl alcohol (IPA), chlorobenzene (CBZ), toluene, ethyl acetate (EA), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 2-methoxyethanol (2-ME), and N-methylpyrrolidone (NMP). The present application does not limit the concentrations of the additive solution and the perovskite solution. The concentrations may be regulated based on the process requirements of the solution method and the thickness of the first film layer 32 and the perovskite layer 31. For example, the concentration of the additive may be 1 to 1.1 mmol / L, and the concentration of the perovskite material may be 1.0 to 1.3 mol / L.

[0064] When the perovskite thin film to be prepared is a composite film, and the composite film includes a stacked second film layer 33 and a perovskite layer 31, step S100 may specifically include: S10c, depositing a perovskite solution containing the perovskite material, annealing at 90-110°C for 90-120 minutes to obtain a perovskite layer 31, depositing an additive solution containing the additive on one side of the perovskite layer 31, annealing at 100-120°C for 15-30 minutes to obtain a second film layer 33, the perovskite layer 31 and the second film layer 33 together constitute the perovskite thin film.

[0065] In some embodiments, the additive solution further includes a third solvent, which may include, but is not limited to, one or more of isopropyl alcohol (IPA), chlorobenzene (CBZ), toluene, ethyl acetate (EA), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 2-methoxyethanol (2-ME), and N-methylpyrrolidone (NMP). The present application does not limit the concentrations of the additive solution and the perovskite solution. The concentrations may be regulated based on the process requirements of the solution method and the thickness of the second film layer 33 and the perovskite layer 31. For example, the concentration of the additive may be 1-1.1 mmol / L, and the concentration of the perovskite material may be 1.0-1.3 mol / L.

[0066] When the perovskite thin film to be prepared is a composite film, and the composite film includes a stacked first film layer 32, a perovskite layer 31, and a second film layer 33, the additive includes a first additive and a second additive. Step S100 may specifically include: S10d, depositing a first solution containing the first additive, annealing at 80-90°C for 10-20 minutes to obtain a first film layer 32, depositing a perovskite solution containing the perovskite material on one side of the first film layer 32, annealing at 90-110°C for 90-120 minutes to obtain a perovskite layer 31, depositing a second solution containing the second additive on a side of the perovskite layer 31 away from the first film layer 32, annealing at 100-120°C for 15-30 minutes to obtain a second film layer 33, the first film layer 32, the perovskite layer 31 and the second film layer 33 together constitute the perovskite thin film.

[0067] It can be understood that the first additive and the second additive are each independently selected from at least one of the additives described above, and the two additives may be the same or different.

[0068] In some embodiments, the first solution may further include a fourth solvent, which may include but is not limited to one or more of IPA, CBZ, toluene, EA, DMF, DMSO, 2-ME, and NMP. The second solution may further include a fifth solvent, which may include but is not limited to one or more of IPA, CBZ, toluene, EA, DMF, DMSO, 2-ME, and NMP. It will be appreciated that the present application also does not limit the concentrations of the first solution, the second solution, and the perovskite solution. Specifically, reference may be made to the process requirements of the solution method and to the thickness of the film to be prepared for regulation. For example, in the first solution and the second solution, the concentration of the additive may be 1 to 1.1 mmol / L, and in the perovskite solution, the concentration of the perovskite material may be 1.0 to 1.3 mol / L.

[0069] In a third aspect, the present application further provides a perovskite cell 100 comprising a stacked first electrode 1, a photoactive layer 3, and a second electrode 2, wherein the photoactive layer 3 comprises the perovskite film described above, or a perovskite film prepared by the preparation method described above. Specifically, the photoactive layer 3 comprises a perovskite film, the material of which includes a perovskite material and an additive, wherein the additive includes at least one compound having the structure represented by formula (I).

[0070] The perovskite cell 100 proposed in the present application uses a perovskite film containing additives as the photoactive layer 3. Since the additives can form multi-component interactions with ions in the perovskite material through the heterocyclic rings, sulfonyl groups, etc. contained in their structure, the nucleation energy barrier of the α phase is reduced and the formation of the δ phase is inhibited, thereby effectively improving the photoelectric conversion efficiency (PCE) and stability of the cell; at the same time, these groups can also interact with uncoordinated cation vacancies and anion vacancies at the grain boundaries, play a role in passivating grain boundary defects and improving crystallization quality, thereby further improving cell performance and stability.

[0071] In summary, the perovskite film provided in this embodiment has high crystalline quality, low defect density and excellent stability. The perovskite cell 100 prepared using the perovskite film has better photoelectric conversion efficiency and stability.

[0072] The first electrode 1 can be one of a bottom electrode and a top electrode, and the second electrode 2 can be the other of the two. The bottom electrode can be a commonly used bottom electrode in the art, such as a metal oxide electrode. The electrode material can include, but is not limited to, at least one of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), and aluminum-doped magnesium oxide (AlMgO). In some embodiments, a substrate, such as a glass substrate, can be disposed on the side of the bottom electrode facing away from the photoactive layer 3. The top electrode can be a commonly used top electrode in the art, such as a metal electrode. The electrode material can include, but is not limited to, one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg, and Ba.

[0073] In some embodiments, the perovskite thin film is a single-layer film, wherein the material of the single-layer film is a mixture of the perovskite material and the additive. In the single-layer film, the molar ratio of the additive to the perovskite material is 0.01 to 0.1:100; and the thickness of the single-layer film is 400 to 900 nm.

[0074] In other embodiments, the perovskite thin film is a composite film comprising a perovskite layer 31 and a modified layer. The modified layer comprises one or both of a first film layer 32 and a second film layer 33, respectively stacked on opposite sides of the perovskite layer 31. The perovskite layer 31 is made of the perovskite material, and the first and second film layers 32, 33 each independently include the additive. The first film layer 32 is located between the first electrode 1 and the perovskite layer 31, and the second film layer 33 is located between the perovskite layer 31 and the second electrode 2. The perovskite layer 31 has a thickness of 300-600 nm; the first film layer 32 has a thickness of 1-100 nm; the second film layer 33 has a thickness of 1-100 nm; and the total thickness of the perovskite layer 31 and the modified layer is 300-800 nm.

[0075] In some embodiments, the perovskite cell 100 further includes a hole transport layer 5, which is disposed between the perovskite cell 100 and the first electrode 1, or between the perovskite cell 100 and the second electrode 2. In other embodiments, the perovskite cell 100 may further include an electron transport layer 4, which is disposed between the perovskite cell 100 and the first electrode 1, or between the perovskite cell 100 and the second electrode 2. In yet other embodiments, the perovskite cell 100 includes a hole transport layer 5 and an electron transport layer 4, which are disposed on both sides of the photoactive layer 3. For example, the perovskite cell 100 may include a first electrode 1, a hole transport layer 5, a photoactive layer 3, an electron transport layer 4, and a second electrode 2 stacked in sequence, or may include a first electrode 1, an electron transport layer 4, a photoactive layer 3, a hole transport layer 5, and a second electrode 2 stacked in sequence.

[0076] In a fourth aspect, the present application also proposes a method for preparing a perovskite cell 100, which can be used to prepare the above-mentioned perovskite cell 100. The preparation method comprises: preparing a plurality of film layers in sequence according to the film layer order of the perovskite cell 100 to be prepared, to obtain the perovskite cell 100. The plurality of film layers refers to the film layers constituting the perovskite cell 100, and may include, for example, a first electrode 1, a photoactive layer 3, and a second electrode 2, or may include a first electrode 1, a hole transport layer 5, a photoactive layer 3, an electron transport layer 4, and a second electrode 2, etc.

[0077] The photoactive layer 3 can be prepared with reference to the above-mentioned method for preparing the perovskite thin film. For example, in some embodiments, the structure of the perovskite cell 100 to be prepared is a first electrode 1, a photoactive layer 3, and a second electrode 2 stacked sequentially from bottom to top, and the photoactive layer 3 is a single layer film. Accordingly, its preparation method includes: mixing the perovskite material, the additive, and a first solvent to obtain a mixed solution; depositing the mixed solution on the first electrode 1, performing a first annealing treatment, and obtaining a photoactive layer 3; and preparing a second electrode 2 on the side of the photoactive layer 3 facing away from the first electrode 1. In other embodiments, the structure of the perovskite cell 100 to be prepared is a first electrode 1, a photoactive layer 3, and a second electrode 2 stacked sequentially from bottom to top, and the photoactive layer 3 is a composite film and the composite film includes a stacked first film layer 32 and a perovskite layer 31, and the first film layer 32 is located between the perovskite layer 31 and the first electrode 1. Correspondingly, the preparation method includes: depositing an additive solution containing an additive on the first electrode 1, annealing at 80~90℃ for 10~20min to obtain a first film layer 32, depositing a perovskite solution containing a perovskite material on the side of the first film layer 32 facing away from the first electrode 1, annealing at 90~110℃ for 90~120min to obtain a perovskite layer 31, the perovskite layer 31 and the first film layer 32 together constitute a photoactive layer 3; and preparing a second electrode 2 on the side of the photoactive layer 3 facing away from the first electrode 1.

[0078] The first electrode 1, the second electrode 2, the electron transport layer 4, the hole transport layer 5, etc. can be prepared using film preparation methods commonly used in the art, such as chemical vapor deposition, coprecipitation, magnetron sputtering, physical vapor deposition, atomic layer deposition, solution method, etc.

[0079] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0080] Example 1 This embodiment provides a formal perovskite solar cell containing a parecoxib additive, the structure of which is: FTO / SnO2 / (parecoxib+FAPbI3) / Spiro-OMeTAD / Au.

[0081] The preparation method of the battery of this embodiment specifically includes the following steps: (1) Substrate pretreatment: Fluorine-doped tin oxide (FTO) glass was cut into 10 cm × 10 cm pieces using a glass cutter and patterned using a nanosecond laser. Each piece had an area of ​​1.5 cm × 2 cm. The FTO glass was then ultrasonically cleaned three times using pure water containing detergent, deionized water, and anhydrous ethanol, each for 15 minutes. After cleaning, the glass was blown dry with cold dry air and placed in a dry, clean container for later use.

[0082] (2) Preparation of electron transport layer: Chemical bath deposition (CBD) was used to prepare SnO2 thin film as the electron transport layer. The thickness of the SnO2 film was about 30 nm. The details are as follows: (2.1) Preparation of SnCl₂ mother liquor: Add 200 mL of deionized water to a clean Shuniu bottle and place in the freezer for approximately 15 minutes, taking care not to freeze the water. The deionized water should be approximately 2°C. Add 2.5 mL of concentrated HCl (38% concentrated hydrochloric acid) to the low-temperature pure water and mix thoroughly. Then, add 2.5 g of urea, 0.548 g of SnCl₂·2H₂O, and 50 μL of thioglycolic acid in that order. Stir thoroughly to obtain the resulting SnCl₂ mother liquor. Store in the refrigerator until ready for use.

[0083] (2.2) Preparation of SnO2 Thin Film: 20 mL of SnCl2 mother liquor was placed in a clean glass container and diluted with 100 mL of deionized water to obtain a diluent. Remove the washed FTO glass and treat it face-up in a UVO (ultraviolet ozone) cleaner for 15 minutes, then clean it with cold, dry air. Place the FTO glass face-up in a glass container containing the diluent. Seal the container with plastic wrap and place it in a 90°C oven for 2 hours.

[0084] (2.3) After heating is complete, remove the FTO glass from the glass container. Rinse the FTO glass 3-5 times with deionized water, then ultrasonically clean it in deionized water for 5 minutes. After ultrasonic cleaning, turn the FTO glass over and rinse it again with deionized water 3-5 times, then ultrasonically clean it in an appropriate amount of deionized water for 5 minutes. Finally, remove the FTO glass, blow dry it with cold, dry air, and anneal it on a 170°C hot plate for 1 hour. After cooling to room temperature, the FTO glass substrate with the SnO2 layer is obtained and stored for future use.

[0085] (3) Preparation of photoactive layer: (3.1) Preparation of a perovskite precursor solution containing parecoxib: Under an inert atmosphere, solid parecoxib powder was accurately weighed on a balance, mixed with FAPbI3 perovskite material powder, and then added with 2-ME solvent and shaken to completely dissolve it to obtain a mixed precursor solution. The mixed precursor solution contained 1 mmol / L parecoxib, 1.0 mol / L perovskite material concentration, and a molar ratio of parecoxib to perovskite material of 0.1:100.

[0086] (3.2) Preparation of the Photoactive Layer: Transfer the SnO2-coated FTO glass substrate and the mixed precursor solution to a nitrogen glove box. Use a pipette to evenly coat the electron transport layer (SnO2 thin film) with an appropriate amount of the mixed precursor solution. Set the spin coater to 5000 rpm, acceleration 1000 rpm / s, and spin for 30 seconds. After the spin is complete, a uniform wet film is obtained. Transfer the wet film to a 100°C hot plate for annealing for 90 minutes, then remove it and allow it to cool to form the photoactive layer. Store it for future use. The thickness of the photoactive layer is approximately 600 nm.

[0087] (4) Preparation of hole transport layer: (4.1) Prepare Spiro-OMeTAD solution: Weigh 520 mg of Li-TFSI (lithium bis(trifluoromethylsulfonylimide)) powder on a balance and dissolve it in 1 mL of ACN (acetonitrile) solvent. Shake well, filter, and prepare a Li salt solution. Weigh 300 mg of Co-TFSI (cobalt bis(trifluoromethylsulfonylimide)) on a balance and dissolve it in 1 mL of ACN solvent. Shake well, filter, and prepare a Co salt solution. Weigh 91.4 mg of Spiro-OMeTAD powder, the hole transport material, on a balance. Add 1 mL of CBZ (chlorobenzene), 21 μL of the Li salt solution, 11.5 μL of the Co salt solution, and 36.5 μL of tBP (tributyl phosphate). Seal the mixture and shake it in an oscillator until completely dissolved to obtain the Spiro-OMeTAD solution.

[0088] (4.2) Transfer the prepared Spiro-OMeTAD solution to a nitrogen glove box. Use a pipette to spin-coat an appropriate amount of Spiro-OMeTAD solution onto the annealed photoactive layer film. Spin-coating parameters: speed 4000 rpm, acceleration 2000 rpm / s, time 20 s. After the hole transport layer is prepared, transfer the device to a drying cabinet. The thickness of the hole transport layer is approximately 200 nm.

[0089] (5) Preparation of gold electrode: The device is transferred to the substrate of the evaporator. In the vacuum evaporator, gold with a thickness of about 80 nm is evaporated on the hole transport layer to obtain a complete perovskite solar cell.

[0090] Example 2 The scheme of this embodiment is basically the same as that of Example 1, except that the molar ratio of parecoxib to perovskite material in the photoactive layer of this embodiment is 0.01:100, and correspondingly, the concentration of parecoxib is 0.1 mmol / L.

[0091] Example 3 The scheme of this embodiment is basically the same as that of Example 1, except that the molar ratio of parecoxib to perovskite material in the photoactive layer of this embodiment is 0.05:100, and accordingly, the concentration of parecoxib is 0.5 mmol / L.

[0092] Example 4 The scheme of this embodiment is basically the same as that of Example 1, except that the molar ratio of parecoxib to perovskite material in the photoactive layer of this embodiment is 0.5:100, and accordingly, the concentration of parecoxib is 5 mmol / L.

[0093] Example 5 The scheme of this embodiment is basically the same as that of Example 1, except that the molar ratio of parecoxib to perovskite material in the photoactive layer of this embodiment is 1:100, and accordingly, the concentration of parecoxib is 10 mmol / L.

[0094] Example 6 The scheme of this embodiment is basically the same as that of embodiment 1, except that the material of the photoactive layer in this embodiment is changed to the perovskite material Cs 0.05 FA 0.95 PbI3 and additive celecoxib. Among them, Cs 0.05 FA 0.95 The preparation steps of PbI3 are as follows: 0.01429g CsI (cesium iodide) powder, 0.17873g FAI (formamidine ammonium iodide) powder and 0.50711g PbI2 (lead iodide) powder are dissolved in DMF-DMSO mixed solvent (the volume ratio of DMF to DMSO is 4:1) and the volume is adjusted to 1mL. After mixing evenly, the perovskite material CsI is dried. 0.05 FA 0.95 PbI3.

[0095] Example 7 The scheme of this embodiment is basically the same as that of embodiment 6, with the only difference being that the additive contained in the photoactive layer of this embodiment is changed to parecoxib.

[0096] Example 8 The scheme of this embodiment is basically the same as that of embodiment 6, with the only difference being that the additive contained in the photoactive layer of this embodiment is changed to etoricoxib.

[0097] Example 9 This embodiment proposes a trans-perovskite solar cell containing a parecoxib additive, the structure of which is: ITO / PTAA / (MAPbBr3) 0.05 (FAPbI3) 0.95 / Parecoxib / (C 60 / BCP) / Ag.

[0098] The preparation method of the battery of this embodiment specifically includes the following steps: (1) Substrate pretreatment: Cut the ITO glass into 2 cm × 2 cm pieces using a glass cutter and pattern it using a nanosecond laser. Then, ultrasonically clean the ITO glass three times using pure water containing detergent, deionized water, and anhydrous ethanol. After cleaning, blow dry with cold dry air and place in a dry and clean container for later use.

[0099] (2) Preparation of hole transport layer: (2.1) Prepare PTAA solution: Weigh 2.5 mg of poly(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA powder) on a balance and dissolve it in 1 mL of CBZ solvent. Seal the container and shake it in an oscillator until completely dissolved. Treat the washed ITO glass with UVO for 15 minutes, facing up, and then blow it clean with cold, dry air.

[0100] (2.2) Transfer the ITO glass substrate and PTAA solution to a nitrogen glove box. Use a pipette to evenly coat the substrate with an appropriate amount of PTAA solution. Set the spin coater to 6000 rpm, 2000 rpm / s acceleration, and spin for 30 seconds. After the spin is complete, a uniform wet film is obtained. Transfer the wet film to a 100°C hot plate for annealing for 15 minutes before removal. The thickness of the hole transport layer is 100 nm.

[0101] (3) Preparation of photoactive layer: (3.1) Preparation of perovskite precursor solution and additive solution: Accurately weigh (MAPbBr3) on a balance 0.05 (FAPbI3) 0.95 Perovskite powder was added with 2-ME solvent to obtain a 1.1 mol / L perovskite precursor solution; parecoxib was accurately weighed and added to IPA solvent, and shaken to completely dissolve it to obtain a 1 mmol / L parecoxib solution.

[0102] (3.2) Preparation of the Photoactive Layer: Transfer the perovskite precursor solution and parecoxib solution to a nitrogen glove box. Use a pipette to evenly coat the hole transport layer with the perovskite precursor solution. Set the spin coater to 4000 rpm, 1000 rpm / s acceleration, and spin for 30 seconds. After spinning, a uniform wet film is obtained. Transfer the wet film to a 100°C hot plate for annealing for 90 minutes before removing it. The perovskite photoactive layer has a thickness of 600 nm. After cooling, use a pipette to evenly coat the perovskite photoactive layer with the parecoxib solution. Set the spin coater to 3000 rpm, 3000 rpm / s acceleration, and spin for 30 seconds. After spinning, transfer the film to a 100°C hot plate for annealing for 15 minutes before removing it. The additive modification layer has a thickness of 30 nm.

[0103] (4) Preparation of electron transport layer and silver electrode: The device was transferred to the evaporator substrate, and C60 (30 nm, 0.1 Å / s), BCP ((2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline)) (7 nm, 0.1 Å / s) and Ag (100 nm, 0.2 Å / s) were sequentially evaporated in the vacuum evaporator to complete the device preparation and obtain a complete perovskite solar cell.

[0104] Comparative Example 1 This comparative example is essentially the same as Example 1, except that no parecoxib additive is added to the photoactive layer of this comparative example, which corresponds to a molar ratio of parecoxib to perovskite material of 0. Accordingly, no parecoxib solid powder is added in step (3.1).

[0105] Comparative Example 2 This comparative example is basically the same as Example 6, except that the additive celecoxib is not added to the photoactive layer of this comparative example, which is equivalent to celecoxib and the perovskite material Cs 0.05 FA 0.95 The molar ratio of PbI3 is 0. Accordingly, no celecoxib solid powder is added in step (3.1).

[0106] Comparative Example 3 This comparative example is essentially the same as Example 9, differing only in that the modified layer containing the additive parecoxib is removed from the photoactive layer. Accordingly, in the preparation method, remove the step "After cooling, use a pipette to evenly apply an appropriate amount of parecoxib solution to the perovskite layer. Set the spin coater to 3000 rpm, 3000 rpm / s acceleration, and rotate for 30 seconds. After rotation, transfer to a 100°C hot plate for annealing for 10 minutes before removal. The additive modified layer has a thickness of 30 nm." Experimental example (1) The photoactive layers in Example 1 (With Pr) and Comparative Example 1 (Control) were tested using a UV-visible spectrophotometer to obtain their in-situ UV-visible absorption spectra to monitor the crystallization process during annealing. Figure 4 , Figure 4 Graph showing the change of the ultraviolet absorption intensity of the photoactive layers prepared in Example 1 and Comparative Example 1 over time during the annealing process.

[0107] As can be seen from the figure, the absorption intensity of the perovskite film (i.e., the photoactive layer) begins to increase after annealing for about 2 seconds, indicating that the perovskite film transforms from a disordered sol-gel phase to a crystalline phase.

[0108] The perovskite film of Example 1 reached stable crystal growth intensity in approximately 18 seconds, which is longer than the perovskite film of Comparative Example 1 (approximately 12 seconds). Furthermore, at the same annealing time, the UV-visible absorption intensity of the film of Example 1 was also higher than that of the film of Comparative Example 1. These results indicate that the addition of the additive provides nucleation sites, reduces grain growth rate, inhibits the formation of δ-FAPbI3, and ultimately improves the quality of the perovskite film.

[0109] (2) The photoactive layers in Example 1 and Comparative Example 1 were observed using a scanning electron microscope (SEM). Figure 5 , Figure 5 These are SEM images of the photoactive layers prepared in Example 1 and Comparative Example 1, wherein Control (left) is a SEM top view of the photoactive layer of Comparative Example 1, Control (right) is a SEM cross-sectional view of the photoactive layer of Comparative Example 1, With Pr (left) is a SEM top view of the photoactive layer of Example 1, and With Pr (right) is a SEM cross-sectional view of the photoactive layer of Example 1.

[0110] As can be seen from the figure, in the top view, the surface of Comparative Example 1 contains a large number of white PbI2 particles, the grain size is uneven, and the texture is rough. The morphology of the perovskite film of Example 1 becomes smoother, the PbI2 particles disappear, the grain size increases, and the grain boundaries decrease; in the cross-sectional view, the perovskite film of Comparative Example 1 has voids, irregular grains, and white PbI2 particles on the top interface. In contrast, the perovskite film of Example 1 forms neatly arranged vertical large grains. This shows that the present application improves the crystallization quality and film-forming effect of the perovskite film and reduces grain boundary defects by adding additives.

[0111] (III) The perovskite cells prepared in Examples 1 to 5 and Comparative Example 1 were tested using a solar simulator to obtain statistical distribution diagrams of the Voc and PCE of the cells. Figure 6 .

[0112] As can be seen from the figure, when the molar ratio of parecoxib to perovskite material in the photoactive layer is between 0.01 and 0.1:100, the corresponding perovskite cell exhibits better Voc and PCE. In particular, when the molar ratio is 0.05:100, the cell's Voc and PCE reach their peak. This indicates that optimizing the doping level of the additive can help improve cell performance.

[0113] (IV) The perovskite cells prepared in Examples 6 to 8 and Comparative Example 2 were tested using a solar simulator to obtain the current density-voltage (JV) curves of the cells. Figure 7 .

[0114] As can be seen from the figure, the current density of each example battery is higher than that of the comparative example battery, and among the examples, Example 6 using celecoxib performs the best, indicating that when additives are added to the photoactive layer, the battery efficiency of the perovskite battery is improved, and for the Cs-based 0.05 FA 0.95 For PbI3 batteries, celecoxib has a more significant improvement effect. 0.05 FA 0.95 PbI3 has a better match.

[0115] (V) Using a solar simulator, the perovskite cells prepared in Example 9 (with Pr) and Comparative Example 3 (Control) and the perovskite cells prepared in Example 1 (with Pr) and Comparative Example 1 (Control) were tested and compared to obtain the JV curves of the cells. Figure 8 and Figure 9 .

[0116] Figure 8 The JV test results of the perovskite cells in Example 9 and Comparative Example 3 are shown. Due to the hysteresis effect, when comparing the efficiency of perovskite cells, the RS data are generally compared. Figure 8 , it can be seen that the Jsc (short-circuit current density) of Example 9 is 25.43 mA·cm -2 , which is close to Comparative Example 3. At the same time, the Voc (open circuit voltage) of Example 9 is 1.161 V, the FF is 0.832, and the PCE (photoelectric conversion efficiency) is 24.59%, which are all greatly improved compared with Comparative Example 3. It can be seen that by providing a modified layer containing additives on one side of the perovskite layer, it is helpful to improve the photoelectric performance of the perovskite battery.

[0117] Figure 9 The JV test results of the perovskite cells in Example 1 and Comparative Example 1 are shown. The Voc of the cell in Example 1 is 1.190 V, and the Jsc is 25.46 mA·cm -2, FF is 0.838, and PCE is 25.38%, both superior to Comparative Example 1. Clearly, in small-area PSCs, the FAPbI3 perovskite solar cell containing parecoxib exhibits superior photoelectric performance. This suggests that incorporating additives into the photoactive layer can help improve the photoelectric performance of perovskite cells.

[0118] (VI) The cells of Example 1 and Comparative Example 1 were placed in an environment of 85°C, and the PCE of the cells was tested by an MPPT solar cell IV characteristic test system to investigate the thermal stability of the cells at high temperatures. The results are as follows: Figure 10 shown.

[0119] As can be seen from the figure, the PCE of the battery gradually decreases over time. However, after 1000 hours, the battery of Example 1 still maintains about 91.08% of the initial PCE, while the battery of Comparative Example 1 only maintains 60.17% of the initial PCE. This shows that the addition of additives to the photoactive layer in this application helps improve the stability of the battery.

[0120] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A perovskite film, characterized in that: The material of the perovskite film includes a perovskite material and an additive, wherein the additive includes at least one compound having a structure represented by formula (I): wherein Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each occurrence of the heteroatoms is independently selected from N or O; Ring B or ring C are each independently selected from a benzene ring, a single heterocycle, a C6~C 18 Any of the fused aromatic rings; L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 a combination of one or more of alkylene groups; The substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group, amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1.

2. The perovskite thin film according to claim 1, characterized in that The general structural formula of the perovskite material is ABX3, wherein A is Cs + , Rb + 、[CH3N=NH] + 、CH3(CH2) n-2 NH3 + 、[NH3(CH2) n NH3] 2+ At least one of n≥2, B is a divalent metal cation selected from Pb 2+ 、Sn 2+ 、Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ 、Mn 2+ 、Co 2+ 、Fe 2+ 、Ge 2+ 、Yb 2+ 、Eu 2+ At least one of, X is selected from Cl - Br - , I - At least one of; and / or, The additive comprises at least one of celecoxib, etoricoxib, rofecoxib, parecoxib, etoricoxib and valdecoxib.

3. The perovskite thin film according to claim 1, characterized in that The perovskite thin film is a single-layer film or a composite film; the material of the single-layer film is a mixture of the perovskite material and the additive; the composite film includes a perovskite layer and a modified layer, and the modified layer includes one or two layers of a first film layer and a second film layer respectively stacked on two opposite sides of the perovskite layer, wherein the material of the perovskite layer includes the perovskite material, and the materials of the first film layer and the second film layer each independently include the additive.

4. The perovskite thin film according to claim 3, characterized in that In the monolayer film: The molar ratio of the additive to the perovskite material is 0.01-0.1:100; and / or, The thickness of the single-layer film is 400-900 nm.

5. The perovskite thin film according to claim 3, characterized in that The composite film satisfies at least one of the following conditions: (1) The thickness of the perovskite layer is 300-600 nm; (2) The thickness of the first film layer is 1-100 nm; (3) the thickness of the second film layer is 1 to 100 nm; and (4) The total thickness of the perovskite layer and the modified layer is 300-800 nm.

6. A method for preparing a perovskite film, characterized in that: include: depositing a material for a perovskite thin film to obtain a perovskite thin film; The material of the perovskite film includes a perovskite material and an additive, wherein the additive includes at least one compound having a structure represented by formula (I): wherein Ring A is selected from a five-membered heterocyclic ring or a six-membered heterocyclic ring, the number of heteroatoms is 1 to 3, and each occurrence of the heteroatoms is independently selected from N or O; Ring B or ring C are each independently selected from a benzene ring, a single heterocycle, a C6~C 18 Any of the fused aromatic rings; L is selected from a single bond, -O-, unsubstituted or substituted C1~C 10 a combination of one or more of alkylene groups; The substituent, R1, R2 and R3 are each independently selected from C1 to C 10 Alkyl, C1~C 10 Alkoxy, halogen group, amino, nitro, carboxyl, aldehyde, C1~C 10 Acyl, C1~C 10 any one or more combinations of alkylamide groups; n1 is 0 or 1, and n2 is 0 or 1.

7. The method for preparing a perovskite thin film according to claim 6, wherein: The steps of depositing the material of the perovskite film to obtain the perovskite film include: mixing the perovskite material, the additive and a first solvent to obtain a mixed solution; depositing the mixed solution and performing a first annealing treatment to obtain a perovskite film; Wherein, the first solvent comprises one or more of isopropyl alcohol, chlorobenzene, toluene, ethyl acetate, N,N-dimethylformamide, dimethyl sulfoxide, 2-methoxyethanol and N-methylpyrrolidone; In the mixed solution, the molar ratio of the additive to the perovskite material is 0.01-0.1:100; The temperature of the first annealing treatment is 90-110° C., and the time of the first annealing treatment is 90-120 minutes.

8. The method for preparing a perovskite thin film according to claim 6, wherein: The steps of depositing the material of the perovskite film to obtain the perovskite film include: Depositing an additive solution containing the additive, annealing at 80-90° C. for 10-20 minutes to obtain a first film layer, depositing a perovskite solution containing the perovskite material on one side of the first film layer, annealing at 90-110° C. for 90-120 minutes to obtain a perovskite layer, wherein the perovskite layer and the first film layer together constitute the perovskite thin film; or, Depositing a perovskite solution containing the perovskite material, annealing at 90-110° C. for 90-120 minutes to obtain a perovskite layer, depositing an additive solution containing the additive on one side of the perovskite layer, annealing at 100-120° C. for 15-30 minutes to obtain a second film layer, wherein the perovskite layer and the second film layer together constitute the perovskite thin film; or, The additives include a first additive and a second additive; a first solution containing the first additive is deposited, and the solution is annealed at 80-90° C. for 10-20 minutes to obtain a first film layer; a perovskite solution containing the perovskite material is deposited on one side of the first film layer, and the solution is annealed at 90-110° C. for 90-120 minutes to obtain a perovskite layer; a second solution containing the second additive is deposited on a side of the perovskite layer away from the first film layer, and the solution is annealed at 100-120° C. for 15-30 minutes to obtain a second film layer; the first film layer, the perovskite layer, and the second film layer together constitute the perovskite thin film.

9. A perovskite battery, characterized in that: The invention comprises a first electrode, a photoactive layer and a second electrode which are stacked, wherein the photoactive layer comprises the perovskite film according to any one of claims 1 to 5, or the perovskite film prepared by the preparation method according to any one of claims 6 to 8.

10. The perovskite cell according to claim 9, characterized in that The perovskite cell further includes a hole transport layer and an electron transport layer, wherein the hole transport layer is arranged between the first electrode and the photoactive layer, and the electron transport layer is arranged between the second electrode and the photoactive layer.

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