A perovskite precursor solution, a battery containing the same, and a preparation method thereof

Abstract

The main purpose of the present invention is to provide a perovskite precursor solution, a battery containing the same, and a preparation method thereof. The perovskite precursor solution includes N-methyl-2-piperidone and CsPbX3, wherein X is I, Br, or Cl, and the molar ratio of N-methyl-2-piperidone to CsPbX3 is 1:(0.5-1). In the present invention, by adding N-methyl-2-piperidone and compounding CsPbX3, a perovskite film can be formed below 100°C. The formed perovskite film is stable and dense, and has a good black phase perovskite crystal structure.

Description

Technical Field

[0001] The present invention belongs to the field of battery materials, and in particular relates to a perovskite precursor solution, a battery containing the same, and a preparation method thereof. Background Art

[0002] All-inorganic cesium lead halide perovskite thin films have attracted considerable attention due to their high absorption coefficient, excellent thermal stability, and charge mobility. The composition of the precursor solution and the annealing temperature both affect the film. Annealing volatilizes the solvent and components, causing grain aggregation and shrinkage, forming defects such as gaps and pores. Furthermore, due to internal crystal structure issues, the perovskite undergoes a rapid phase transition at room temperature, forming a yellow delta phase that lacks photovoltaic properties, compromising the power conversion efficiency (PCE) and stability of solar cells (PSCs).

[0003] High-temperature sintering is often used in existing technologies to promote perovskite nucleation and improve film stability. However, high-temperature sintering affects the volatilization of organic solvents and increases the grain boundaries of the film. It is impossible to reduce the defect density of the film while ensuring that the crystallinity and grain structure of the film are not affected. Summary of the Invention

[0004] The main purpose of the present invention is to provide a perovskite precursor solution, a battery containing the same and a preparation method thereof, aiming to provide a perovskite precursor solution that can form a black phase and has good crystallization under low temperature conditions.

[0005] To achieve the above object, the present invention provides a perovskite precursor solution, wherein the perovskite precursor solution comprises N-methyl-2-piperidone and CsPbX3, wherein X is I, Br or Cl, and N-methyl-2-piperidone and Cs a Pb b X c The molar ratio is 1:(0.5~1).

[0006] Optionally, the composite raw materials of CsPbX3 include PbX2 and CsX; and / or,

[0007] X is 1.

[0008] Optionally, the perovskite precursor solution further comprises CsY, wherein Y is I, Br or Cl, Y is different from the element of X, and the molar ratio of CsPbX3 to CsY is 1:(0.001-0.005); and / or,

[0009] The perovskite precursor solution also includes a solvent.

[0010] The present invention also provides a method for preparing the above-mentioned perovskite precursor solution, which comprises the following steps:

[0011] The CsPbX3 is mixed with N-methyl-2-piperidone to obtain the perovskite precursor solution.

[0012] Optionally, the step of mixing the CsPbX3 with N-methyl-2-piperidone to obtain the perovskite precursor solution comprises:

[0013] PbX2, CsX, N-methyl-2-piperidone and CsY are added to a solvent and mixed to obtain the perovskite precursor solution, where Y is I, Br or Cl, and Y is different from the element of X.

[0014] In addition, the present invention also provides a perovskite cell, which includes a substrate, an electron transport layer, a perovskite film, a hole transport layer and an electrode stacked in sequence, wherein the perovskite film is prepared from the above-mentioned perovskite precursor solution.

[0015] Optionally, the substrate is a flexible conductive indium tin oxide substrate; and / or,

[0016] The material of the electron transport layer is SnO2; and / or,

[0017] The material of the hole transport layer is 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene; and / or,

[0018] The material of the electrode is metal; and / or,

[0019] The thickness of the electrode is 80 nm to 100 nm.

[0020] In addition, the present invention provides a method for preparing the above-mentioned perovskite battery, which comprises the following steps:

[0021] The substrate is cleaned with a detergent and dried to obtain a standby substrate;

[0022] depositing an electron transport layer raw material on the surface of the spare substrate to form the electron transport layer;

[0023] Spin-coating the perovskite precursor solution onto the surface of the electron transport layer, and annealing at 85-95° C. to form the perovskite film;

[0024] Depositing hole transport layer raw materials on the surface of the perovskite film to form the hole transport layer;

[0025] The electrode material is deposited on the surface of the hole transport layer to form the electrode, thereby obtaining the perovskite cell.

[0026] Optionally, cleaning the substrate with a detergent comprises: ultrasonically cleaning the ITO flexible conductive substrate in deionized water, anhydrous ethanol, acetone, and isopropyl tone in sequence for 10 to 20 minutes each; and / or,

[0027] The step of depositing the electron transport layer raw material on the surface of the spare substrate to form the electron transport comprises: alternately spin coating a 10mg / mL to 15mg / mL SnO2 colloidal solution and a 10mg / mL to 15mg / mL SnO2 nanocrystal solution on the substrate surface, and annealing to form the electron transport layer; and / or,

[0028] The step of depositing a hole transport layer raw material on the surface of the perovskite film to form the hole transport layer comprises:

[0029] Spin-coating 10 mg / mL to 20 mg / mL of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene on the surface of the perovskite film, annealing at 90° C. to 110° C. to form the hole transport layer, and obtaining a third preparation; and / or,

[0030] The step of depositing the electrode material on the surface of the hole transport layer to form the electrode and obtain the perovskite cell includes: depositing the metal material on the surface of the hole transport layer by thermal evaporation to obtain the perovskite cell.

[0031] In the present invention, by adding N-methyl-2-piperidone and compounding it with CsPbX3, a perovskite film can be formed below 100°C, and the formed perovskite film is stable and dense, and has a good black phase perovskite crystal form. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 This is a structural diagram of the perovskite battery of the present invention;

[0034] Figure 2 XRD test patterns of perovskite films prepared from perovskite precursor solutions of Example 1 and Comparative Examples 1 to 3;

[0035] Figure 3 SEM images of perovskite films prepared from perovskite precursor solutions of Example 1 and Comparative Examples 1 to 3;

[0036] Figure 4 This is an appearance inspection diagram of the perovskite thin films prepared using the perovskite precursor solutions of Example 1 and Comparative Examples 1 to 3;

[0037] Figure 5 SEM images of the perovskite films prepared in Examples 10 to 13;

[0038] Figure 6 This is the electrochemical curve of the perovskite battery in Example 15;

[0039] Figure 7 These are XRD test patterns of the perovskite films prepared in Example 1 and Comparative Example 4.

[0040] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0042] It should be noted that, in the embodiments, those without specifying specific conditions, are carried out according to conventional conditions or the conditions recommended by the manufacturer. Those for reagents or instruments used that do not specify the manufacturer are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes schemes A, B, or A and B that meet the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on those of ordinary skill in the art. When the combination of the technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work belong to the scope of protection of the present invention.

[0043] In view of the fact that the existing perovskite precursor solution cannot form a perovskite film that is both stable and has excellent crystal nuclei under low temperature conditions, the present invention provides a perovskite precursor solution, which includes N-methyl-2-piperidone and CsPbX3, wherein X is I, Br or Cl, and the molar ratio of N-methyl-2-piperidone to CsPbX3 is 1:(0.5~1).

[0044] In the present invention, by adding N-methyl-2-piperidone to CsPbX3, a perovskite film can be formed below 100°C. The formed perovskite film is stable and dense, with a good black phase perovskite crystal structure. At the same time, the inventor's research team discovered that the compounding ratio of N-methyl-2-piperidone and CsPbX3 is a key factor in determining whether a black phase perovskite film will be formed in the later stage. When the amount of N-methyl-2-piperidone is insufficient, a yellow phase without a photoelectric effect will be generated.

[0045] In some embodiments, the composite raw materials of CsPbX3 include PbX2 and CsX; the composite raw materials are the above-mentioned PbX2 and CsX, which will increase the degree of complexation between PbX2 and N-methyl-2-piperidone, thereby forming a better crystal phase.

[0046] It should be noted that, under the premise of obtaining a black phase, X can be I, Br, Cl, and in some embodiments, can be I. As an all-inorganic perovskite, the black phase CsPbI3 perovskite has excellent thermal stability and a band gap of approximately 1.7 eV, and is considered to be one of the candidate materials for high-efficiency solar cells (PSCs).

[0047] In some embodiments, the perovskite precursor solution further includes 1mM to 5mM CsY, where Y is I, Br, or Cl, and Y is an element different from X. The inventors' research team found that adding a small amount of CsY to the perovskite precursor solution can make the crystal nuclei denser and more clearly defined, but adding more than 5mM CsY can increase the spacing between the crystal nuclei. Specifically, when Y is Cl, Cl can be removed during the formation of the perovskite film.

[0048] Obviously, the perovskite precursor solution also includes a solvent, which is used to disperse the above raw materials to form a dispersed system.

[0049] In addition, the present invention also provides a method for preparing the above-mentioned perovskite precursor solution, and the method for preparing the perovskite precursor solution comprises the following steps:

[0050] The CsPbX3 is mixed with N-methyl-2-piperidone to obtain the perovskite precursor solution. Specifically, the method includes adding PbX2, CsX, N-methyl-2-piperidone, and CsY into a solvent and mixing them to obtain the perovskite precursor solution.

[0051] In some embodiments, the solvent includes at least one of dimethylformamide and dimethyl sulfoxide. Using the above solvent, the raw materials of the perovskite precursor solution can be completely dispersed.

[0052] In addition, the present invention also provides a perovskite battery, see Figure 1The perovskite cell comprises a substrate 1, an electron transport layer 2, a perovskite thin film 3, a hole transport layer 4, and an electrode 5 stacked in sequence, wherein the perovskite thin film is deposited from the perovskite precursor solution. The perovskite thin film is prepared from the perovskite precursor solution and then assembled into a cell. Due to the fine crystalline phase of the perovskite thin film, the assembled perovskite cell has excellent photovoltaic properties.

[0053] It should be noted that, under the premise of ensuring its photovoltaic properties, the substrate material of the present invention is not limited. More preferably, the substrate is a flexible conductive ITO substrate.

[0054] It should be noted that the electron transport layer material of the present invention is not limited, provided that its photovoltaic properties are ensured. More preferably, in some embodiments, the electron transport layer material is SnO2. In particular, when the substrate is an ITO flexible conductive substrate, SnO2 has a lower preparation temperature, which allows for better compatibility with the substrate material and better band gap matching, resulting in higher cell efficiency.

[0055] In some embodiments, the material of the hole transport layer of the present invention is not limited as long as its photovoltaic properties are ensured. More preferably, it is 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene.

[0056] In some embodiments, the electrode material is metal. It should be noted that the metals selected for the electrode materials of the present invention are all commonly used metals. Specifically, in some embodiments, the metal is silver.

[0057] It should be noted that, under the premise of ensuring its photovoltaic characteristics, the electrode is designed according to actual conditions, and the thickness of the electrode is 80nm to 100nm.

[0058] In addition, the present invention also provides a method for preparing the above-mentioned perovskite battery, which comprises the following steps:

[0059] Step S10: cleaning the substrate with a detergent and drying it to obtain a spare substrate;

[0060] Step S20: depositing an electron transport layer raw material on the surface of the spare substrate to form the electron transport layer;

[0061] Step S30: spin-coating the perovskite precursor solution onto the surface of the electron transport layer, and annealing at 85-95° C. to form the perovskite thin film;

[0062] Step S40: depositing a hole transport layer raw material on the surface of the perovskite film to form the hole transport layer;

[0063] Step S50: depositing the electrode material on the surface of the hole transport layer to form the electrode and obtain the perovskite cell.

[0064] In some embodiments, step S10 includes ultrasonically cleaning the ITO flexible conductive substrate in deionized water, anhydrous ethanol, acetone, and isopropyl ketone, respectively, for 10 to 20 minutes. By sequentially cleaning the substrate in the aforementioned solutions, stains on the substrate can be thoroughly removed, thereby preventing the stains from affecting the performance of the perovskite cell.

[0065] In some embodiments, step S20 includes: alternately spin-coating a 10 mg / mL to 15 mg / mL Alfa-SnO2 colloidal solution and a 10 mg / mL to 15 mg / mL SnO2 nanocrystal solution on the surface of the substrate, and after annealing, forming the electron transport layer to obtain the first preparation.

[0066] When Alfa-SnO2 colloid solution and SnO2 nanocrystal solution are used for alternating deposition, the deposited SnO2 defect states can be reduced, thus playing the role of interface passivation.

[0067] It should be noted that, in the present invention, the number of alternations is not limited. Specifically, in some embodiments, the number of alternations is 3 times.

[0068] Step S40 includes:

[0069] Poly(3-hexylthiophene) with a content of 10 mg / mL to 20 mg / mL is spin-coated on the surface of the perovskite film, and annealed at 90°C to 110°C to form the hole transport layer to obtain a third preparation body; the hole transport layer generated under the above conditions has better electrical properties.

[0070] Step S50 includes: depositing a metal material on the surface of the hole transport layer by thermal evaporation to form the electrode, thereby obtaining the perovskite cell. In the present invention, the electrode is deposited by thermal evaporation, which can make the metal deposition more uniform.

[0071] The technical solutions of the present invention are further described in detail below in conjunction with specific embodiments and drawings. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0072] In the examples of the present invention, Alfa-SnO2 used was purchased from Sigma;

[0073] SnO2 nanocrystals (SnO2 NCs) were synthesized using a low-temperature hydrothermal method. The preparation steps are as follows: an anhydrous SnCl4 solution was diluted to 0.15M with cold deionized water and then stored in an oven at 90°C. After one hour of hydrothermal treatment, the solution was washed three times with a mixture of ether and isopropanol and then centrifuged to obtain SnO2 NCs.

[0074] Examples 1 to 8

[0075] Examples 1 to 8 respectively provide a perovskite precursor solution, the ingredients and compositions of which are shown in Table 1. In Examples 1 to 3, the solvent is DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) in a volume ratio of 4:1.

[0076] Table 1 Perovskite precursor solutions of Examples 1 to 3

[0077]

[0078] Examples 1 to 8 also provide a method for preparing the above-mentioned perovskite precursor solution, and the specific method is as follows:

[0079] Dissolve N-methyl-2-piperidone, PbI2, CsI and CsCl in a solvent according to the contents in Table 1, and shake thoroughly at room temperature for 10 to 12 hours to form a precursor solution.

[0080] Example 9

[0081] This embodiment provides a perovskite cell, comprising a substrate, an electron transport layer, a perovskite film, a hole transport layer and an electrode stacked in sequence, wherein the substrate is a flexible conductive ITO substrate, the material of the electron transport layer is SnO2, the perovskite film is deposited by the perovskite precursor solution of Example 1, the material of the hole transport layer is 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, the material of the electrode is Ag, and the thickness of the electrode is 90 nm.

[0082] This embodiment also provides a method for preparing the above-mentioned perovskite battery, comprising the following steps:

[0083] Step S10: ultrasonically clean the ITO flexible conductive substrate in deionized water, anhydrous ethanol, acetone, and isopropyl tone for 15 min each, and finally blow dry with nitrogen gas for standby use;

[0084] Step S20: The purchased Alfa-SnO2 colloidal dispersion in water was first diluted with H2O and then dropwise diluted with isopropyl alcohol (IPA) under continuous stirring to a final H2O / IPA volume ratio of 1:1 and a dilution concentration of approximately 10 mg / mL. The synthesized SnO2 NCs were also diluted with isopropyl alcohol at a concentration of approximately 10 mg / mL. The two solutions were alternated repeatedly until three layers of each solution were stacked. The mixture was then annealed at 140°C for 1 hour to form the electron transport layer.

[0085] Step S30: The perovskite precursor solution of Example 1 is evenly coated on the electron transport layer by a one-step solution spin coating method, and the coated ITO conductive glass is placed on a hot plate at 90° C. and annealed for 5 minutes to obtain a crystallized perovskite film.

[0086] Step S40: Spin-coat 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene at a concentration of 15 mg / mL on the surface of the perovskite film at a rate of 2000 rpm / s to 4000 rpm / s for 26 seconds, and then anneal at 100°C for 3 minutes to form a hole transport layer.

[0087] Step S50: Deposit Ag metal electrodes by thermal evaporation and evacuate to a vacuum degree of 2.5×10 -5 Pa, the deposition thickness is 90nm.

[0088] Examples 10 to 13

[0089] Examples 10 to 13 provide perovskite cells, which have structures and preparation methods that are substantially the same as those of Example 9, with the only difference being that the perovskite precursor solution used in the perovskite film is as shown in Table 2.

[0090] Table 2 Perovskite precursor solutions used in Examples 10 to 13

[0091]

[0092]

[0093] Example 14

[0094] This embodiment provides a perovskite battery, the structure of which is substantially the same as that of embodiment 9, the only difference being that the electrode thickness is 80 nm.

[0095] This embodiment also provides a method for preparing the above-mentioned perovskite battery, and the specific operations are as follows:

[0096] Step S10: ultrasonically clean the ITO flexible conductive substrate in deionized water, anhydrous ethanol, acetone, and isopropyl ketone for 20 min each, and finally blow dry with nitrogen gas for standby use;

[0097] Step S20: The purchased Alfa-SnO2 colloidal dispersion was first diluted with H2O in water and then diluted dropwise with isopropyl alcohol (IPA) under continuous stirring to a final volume ratio of H2O / IPA of 1:1 and a dilution concentration of approximately 15 mg / mL. The synthesized SnO2NCs were also diluted with isopropyl alcohol at a concentration of approximately 15 mg / mL. The two configurations were alternated repeatedly until two layers of each configuration were stacked alternately. The mixture was then annealed at 130°C for 1.5 hours to form an electron transport layer.

[0098] Step S30: The perovskite precursor solution of Example 1 is evenly coated on the electron transport layer by a one-step solution spin coating method, and the coated ITO conductive glass is placed on a hot plate at 95° C. and annealed for 8 minutes to obtain a crystallized perovskite film.

[0099] Step S40: Spin-coat 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene at a concentration of 12 mg / mL on the surface of the CsPbI3 film at a rate of 3000 rpm / s to 4500 rpm / s for 30 seconds, and then anneal at 110°C for 5 minutes to form a hole transport layer.

[0100] Step S50: Deposit Ag metal electrodes by thermal evaporation and evacuate to a vacuum degree of 2.0×10 -5 Pa, the deposition thickness is 80nm.

[0101] Example 15

[0102] This embodiment provides a perovskite battery, the structure of which is substantially the same as that of embodiment 9, the only difference being that the electrode thickness is 100 nm.

[0103] This embodiment also provides a method for preparing the above-mentioned perovskite battery, and the specific operations are as follows:

[0104] Step S10: ultrasonically clean the ITO flexible conductive substrate in deionized water, anhydrous ethanol, acetone, and isopropyl ketone for 20 min each, and finally blow dry with nitrogen gas for standby use;

[0105] Step S20: The purchased Alfa-SnO2 colloidal dispersion was first diluted with H2O in water and then diluted dropwise with isopropyl alcohol (IPA) under continuous stirring to a final volume ratio of H2O / IPA of 1:1 and a dilution concentration of approximately 14 mg / mL. The synthesized SnO2NCs were also diluted with isopropyl alcohol at a concentration of approximately 12 mg / mL. The two configurations were alternated repeatedly until two layers of each configuration were stacked alternately, and then annealed at 130°C for 1.5 hours to form an electron transport layer.

[0106] Step S30: The perovskite precursor solution of Example 1 is evenly coated on the electron transport layer by a one-step solution spin coating method, and the coated ITO flexible conductive substrate is placed on a hot plate at 95° C. and annealed for 8 minutes to obtain a crystallized perovskite film.

[0107] Step S40: Spin-coat 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene at a concentration of 20 mg / mL on the perovskite wave massage surface at a rate of 3500 rpm / s to 50000 rpm / s for 35 seconds, and then anneal at 100°C for 6 minutes to form a hole transport layer.

[0108] Step S50: Deposit Ag metal electrodes by thermal evaporation and evacuate to a vacuum degree of 2.0×10 -5 Pa, the deposition thickness is 100 nm.

[0109] Comparative Example 1

[0110] This comparative example 1 provides a perovskite precursor solution, the components and preparation method of which are the same as those of Example 1, except that the concentration of CsPbI3 is 1.0 mol / L and the concentration of N-methyl-2-piperidone is 0.5 mol / L.

[0111] The above-mentioned perovskite film is used to prepare a perovskite cell, and its structure and preparation method are consistent with those of Example 9.

[0112] Comparative Example 2

[0113] This comparative example provides a perovskite precursor solution comprising 0.5 M CsPb2I5 and 1 M N-methyl-2-piperidone.

[0114] The above-mentioned perovskite film is used to prepare a perovskite cell, and its structure and preparation method are consistent with those of Example 9.

[0115] Comparative Example 3

[0116] This comparative example provides a perovskite precursor solution comprising 0.5 M Cs 2 PbI 4 and 1 M N-methyl-2-piperidone.

[0117] The above-mentioned perovskite film is used to prepare a perovskite cell, and its structure and preparation method are consistent with those of Example 9.

[0118] Comparative Example 4

[0119] This comparative example provides a perovskite precursor solution, and its preparation method is as follows:

[0120] Dimethylamine iodide (DMAI), PbI2 and CsI were dissolved in DMSO solution and fully shaken at room temperature for 10 to 12 hours to form a CsPbI3 precursor solution. The ratio of DMAI, PbI2 and CsI was 76.56 mg, 230.5 mg and 129.93 mg, of which DMSO was 1 ml.

[0121] The perovskite cell was prepared using the above perovskite film, and its structure and preparation method were consistent with those of Example 9, except that the annealing temperature of the deposited perovskite film was 90°C.

[0122] Test Examples

[0123] 1) The perovskite films prepared from the perovskite precursor solutions of Example 9 and Comparative Examples 1 to 3 were subjected to XRD, SEM and appearance observation. The XRD test results are as follows: Figure 2 As shown in the SEM test results, Figure 3 The appearance observation results are shown as Figure 4 As shown; the perovskite film prepared in Comparative Example 4 was subjected to XDR detection, and the results of XRD detection of Example 1 and Comparative Example 4 were compared. Figure 7 shown.

[0124] The results show that compared with Comparative Example 1, Example 1 adds N-methyl-2-piperidone, and the molar ratio of N-methyl-2-piperidone to CsPbI3 is within the range of 1: (0.5-1), and its XRD characteristic peaks show that a black phase crystal phase is obtained;

[0125] Compared with Comparative Examples 2 to 3, the solutes in Example 1 are CsPbI3 and N-methyl-2-piperidone. Combined with the XRD peak type and SEM, it can be seen that when the compound raw materials are compounded into CsPbI3, its black phase crystal phase is the sharpest, the crystal nucleus forms a clear boundary, and is relatively dense with few holes. In terms of appearance, the image of CsPbI3 has obviously turned black.

[0126] 2) The perovskite films prepared in Examples 10 to 15 were subjected to SEM examination, wherein the test results of Examples 10 to 13 are as follows: Figure 5 The results show that after adding CsCl, the boundary of its crystal form is clearer and more dense. At the same time, the inventor's research team found that the proportion of CsCl added is also one of the important conditions for controlling the crystal form. When the molar ratio of CsPb3X3 to CsY is 1:(0.001~0.005), its crystal nucleus does not separate. The results of Examples 14~15 and the perovskite films prepared using the perovskite precursor solution of Examples 6~8 are also similar. When the molar ratio of CsPbX3 to CsY is 1:0.005, its crystal nucleus is round and more dense.

[0127] 3) The perovskite cells of Examples 9 to 15 were subjected to electrochemical testing.

[0128] Testing method: The JV curve of the perovskite solar cell was measured in a room environment using a Kasili 2400 source meter. The light source was a solar simulator (Oriel 94023A, 300W) matching AM1.5G. The light intensity was 100mW / cm 2 , calibrated by a standard silicon reference solar cell (Oriel, VLSI Standard). All devices were tested using a ferrous metal aperture, with an active area of ​​0.09 cm for the small devices. 2 .

[0129] The test results show that Examples 9 to 15 all have good electrochemical properties. Among them, the electrochemical test of the perovskite battery of Example 15 is as follows: Figure 6 As shown in the figure, the PSK-F curve is the forward sweep JV curve, and the reverse sweep PSK-R is the reverse sweep JV curve. The circuit voltage (Voc) is 0.98V and the short-circuit current density (Jsc) reaches 21.09mA / cm 2 , the fill factor (FF) reaches 78.2%, and the photoelectric conversion efficiency reaches 15.01%, with good electrical efficiency.

[0130] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. A perovskite precursor solution, characterized in that The perovskite precursor solution includes N-methyl-2-piperidone, CsPbX3 and CsY, wherein the composite raw materials of the CsPbX3 include PbX2 and CsX, X is I, and the molar ratio of N-methyl-2-piperidone to CsPbX3 is 1:(0.5~1), Y is Br or Cl, and the molar ratio of the CsPbX3 to CsY is 1:(0.001~0.005); the annealing temperature of the perovskite precursor solution is 85~95°C.

2. The perovskite precursor solution according to claim 1, wherein The perovskite precursor solution also includes a solvent.

3. A method for preparing a perovskite precursor solution according to claim 1 or 2, characterized in that: The method for preparing the perovskite precursor solution comprises the following steps: The CsPbX3 is mixed with N-methyl-2-piperidone to obtain the perovskite precursor solution.

4. The method for preparing a perovskite precursor solution according to claim 3, wherein: The step of mixing the CsPbX3 with N-methyl-2-piperidone to obtain the perovskite precursor solution comprises: PbX2, CsX, N-methyl-2-piperidone and CsY are added to a solvent and mixed to obtain the perovskite precursor solution, where Y is I, Br or Cl, and Y is different from the element of X.

5. A perovskite battery, characterized in that: The perovskite cell comprises a substrate, an electron transport layer, a perovskite film, a hole transport layer and an electrode stacked in sequence, wherein the perovskite film is prepared from the perovskite precursor solution according to claim 1 or 2.

6. The perovskite cell according to claim 5, wherein The substrate is a flexible conductive indium tin oxide substrate; and / or, The material of the electron transport layer is SnO2; and / or, The material of the hole transport layer is 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene; and / or, The material of the electrode is metal; and / or, The thickness of the electrode is 80nm~100nm.

7. A method for preparing a perovskite battery according to any one of claims 5 or 6, characterized in that: The preparation method of the perovskite battery comprises the following steps: The substrate is cleaned with a detergent and dried to obtain a standby substrate; depositing an electron transport layer raw material on the surface of the spare substrate to form the electron transport layer; Spin-coating the perovskite precursor solution onto the surface of the electron transport layer, and annealing at 85-95° C. to form the perovskite film; Depositing hole transport layer raw materials on the surface of the perovskite film to form the hole transport layer; The electrode material is deposited on the surface of the hole transport layer to form the electrode, thereby obtaining the perovskite cell.

8. The method for preparing a perovskite battery according to claim 7, wherein: Cleaning the substrate with a detergent comprises: ultrasonically cleaning the flexible conductive indium tin oxide substrate in deionized water, anhydrous ethanol, acetone, and isopropyl tone for 10 to 20 minutes each; and / or, The step of depositing the electron transport layer raw material on the surface of the spare substrate to form the electron transport layer comprises: alternately spin-coating a colloidal solution containing 10 mg / mL to 15 mg / mL Alfa-SnO2 and a solution containing 10 mg / mL to 15 mg / mL SnO2 nanocrystals on the substrate surface, and annealing to form the electron transport layer to obtain a first preparation; and / or, The step of depositing the hole transport layer raw material on the surface of the perovskite film to form the hole transport layer includes: Spin-coating 10 mg / mL to 20 mg / mL of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene on the surface of the perovskite film, annealing at 90° C. to 110° C. to form the hole transport layer, and obtaining a third preparation; and / or, The step of depositing the electrode material on the surface of the hole transport layer to form the electrode and obtain the perovskite cell includes: depositing the metal material on the surface of the hole transport layer by thermal evaporation to obtain the perovskite cell.

9. The method for preparing a titanium ore battery according to claim 8, wherein: The SnO2 nanocrystals are prepared by the following steps: Sn 4+ The inorganic salt solution is diluted to 0.1-0.2 M, subjected to hydrothermal treatment for one hour, and then washed with a mixed solution of ether and isopropanol. The solid is collected after the liquid is separated.

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