An all-organic perovskite material and its preparation method

Abstract

This application relates to the technical field of perovskite materials, and provides an all-organic perovskite material and a preparation method thereof. The structural general formula is ABX3, where A is a divalent cation containing a pyridine ring, B is N2H5 + , and X is a halogen anion and / or a pseudohalogen anion. For the all-organic perovskite material provided by this application, with the structural general formula of ABX3, based on the molecular structure of the existing perovskite materials, by using a divalent cation containing a pyridine ring to replace the organic cation, a divalent cation containing a pyridine ring is introduced at the A position to increase the intermolecular force within the all-organic perovskite material. At the same time, N2H5 + is used to replace the ammonium ion in the existing perovskite materials to enhance the hydrogen bond force, which can significantly reduce the band gap of the all-organic perovskite material of this application, so that the light absorption can extend to the long-wave ultraviolet or even the visible light region. Therefore, the novel all-organic perovskite of this application has good application prospects in the field of narrow-bandgap optoelectronics.

Description

Technical Field

[0001] This application belongs to the technical field of perovskite materials, and particularly relates to an all-organic perovskite material and a preparation method thereof. Background Art

[0002] Perovskite is a crystalline material with a molecular general formula of ABX3, where A is a divalent cation, B is a monovalent cation, and X is an anion. Each A cation is surrounded by an octahedron formed by B cations and X anions together. It has excellent structural properties and high photoelectric conversion efficiency, and is widely used in fields such as photovoltaics and LEDs. Using organic ions to replace metal ions such as lead and tin in perovskite materials to make all-organic perovskite materials has received increasing attention in recent years. However, the existing all-organic perovskite materials have a very large bandgap (forbidden band width), up to more than 6 eV, so they can only be applied in fields such as dielectrics, X-rays, and γ-rays, which limits the application of all-organic perovskite materials in narrow-bandgap optoelectronic fields. Summary of the Invention

[0003] The purpose of this application is to provide an all-organic perovskite material and a preparation method thereof, aiming to solve the problem that the existing all-organic perovskite materials do not have a light response in the range from long-wave ultraviolet to visible light.

[0004] To achieve the above application purpose, the technical solution adopted in this application is as follows:

[0005] In the first aspect, this application provides an all-organic perovskite material with a structural general formula of ABX3, where A is a divalent cation containing a pyridine ring, B is N2H5 + , and X is a halogen anion and / or a pseudohalogen anion.

[0006] In the second aspect, this application provides a preparation method for an all-organic perovskite material, including the following steps:

[0007] Mix unprotonated A and BX with an acidic solution for reaction treatment to obtain an all-organic perovskite material as shown in ABX3.

[0008] Compared with the prior art, this application has the following beneficial effects:

[0009] The all-organic perovskite material provided in the first aspect of this application has a structural general formula of ABX3. On the basis of the molecular structure of the existing perovskite materials, by using a divalent cation containing a pyridine ring to replace the existing organic cation and introducing a divalent cation containing a pyridine ring at the A position, the interionic force in the all-organic perovskite material can be increased. At the same time, using N2H5 +Replacing the ammonium ions in the existing perovskite materials can enhance the hydrogen bond force, significantly reducing the band gap of the all-organic perovskite materials of the present application, so that the light absorption can extend to the long-wave ultraviolet (UVA, 320 - 400 nm) or even the visible light region. Therefore, the novel all-organic perovskite of the present application has good application prospects in the field of narrow-bandgap optoelectronics.

[0010] The preparation method of the all-organic perovskite material provided in the second aspect of the present application can generate the all-organic perovskite material shown as ABX3 by mixing unprotonated A and BX with an acidic solution for reaction. This preparation method can introduce divalent cations (A) containing pyridine rings from the raw materials, enabling the prepared all-organic perovskite material to have a lower band gap and realizing light response in the long-wave ultraviolet to visible light region. In addition, this preparation method has a simple process and is suitable for industrial production, providing the possibility for the optoelectronic applications of this type of novel all-organic perovskite. Brief Description of the Drawings

[0011] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following-described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0012] Figure 1 It is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 1 of the present application;

[0013] Figure 2 It is the ultraviolet-visible light absorption spectrum of the all-organic perovskite material provided in Example 1 of the present application;

[0014] Figure 3 It is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 2 of the present application;

[0015] Figure 4 It is the ultraviolet-visible light absorption spectrum of the all-organic perovskite material provided in Example 2 of the present application;

[0016] Figure 5 It is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 3 of the present application;

[0017] Figure 6 It is the ultraviolet-visible light absorption spectrum of the all-organic perovskite material provided in Example 3 of the present application;

[0018] Figure 7 It is the X-ray diffraction pattern of the all-organic perovskite material provided in Comparative Example 1 of the present application;

[0019] Figure 8 It is the ultraviolet-visible light absorption spectrum of the all-organic perovskite material provided in Comparative Example 1 of this application. Specific Embodiments

[0020] In order to make the technical problems to be solved, technical solutions and beneficial effects of this application clearer and more understandable, the following further details this application in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0021] In this application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0022] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression below refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0023] It should be understood that in various embodiments of this application, the magnitudes of the sequence numbers of the above processes do not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of this application.

[0024] The terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms "a", "the", and "said" used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0025] The weights of the relevant components mentioned in the specification of the embodiments of this application not only can refer to the specific contents of each component, but also can represent the proportional relationship of the weights between each component. Therefore, as long as the contents of the relevant components in the specification of the embodiments of this application are scaled up or down in proportion, they are within the scope disclosed in the specification of the embodiments of this application. Specifically, the mass described in the specification of the embodiments of this application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0026] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0027] In the first aspect of the embodiments of the present application, a fully organic perovskite material is provided, and its structural general formula is ABX3, where A is a divalent cation containing a pyridine ring, B is N2H5 + , and X is a halogen anion and / or a pseudohalogen anion.

[0028] For the fully organic perovskite material provided by the embodiments of the present application, with the structural general formula of ABX3, on the basis of the molecular structure of the existing perovskite material, by using a divalent cation containing a pyridine ring to replace the existing organic cation and introducing a divalent cation containing a pyridine ring at the A position, the intermolecular force within the fully organic perovskite material can be increased. At the same time, using N2H5 + to replace the ammonium ion in the existing perovskite material can enhance the hydrogen bond force, and can greatly reduce the band gap of the fully organic perovskite material of the present application, so that the light absorption can extend to the long-wave ultraviolet or even visible light region. Therefore, the novel fully organic perovskite of the present application has good application prospects in the field of narrow-bandgap optoelectronics.

[0029] In the embodiment, in the fully organic perovskite material represented by ABX3, B is N2H5 + , then the selection of A and X needs to meet the requirements of the tolerance factor α necessary for the perovskite crystal form, that is, the tolerance factor:

[0030]

[0031] where r A , r B , r X are the respective corresponding ionic radii.

[0032] In the embodiment, the selection of A and X makes the tolerance factor of the fully organic perovskite material of the embodiments of the present application be 0.8 to 1.10. Within this tolerance factor range, the fully organic perovskite material provided by the embodiments of the present application can have better structural stability.

[0033] In the embodiment, the divalent cation containing a pyridine ring is selected from at least one of the following formulas 1 to 9:

[0034]

[0035] Among them, R1 in Formula 1 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R2 in Formula 2 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R3 in Formula 3 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R4 in Formula 4 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R5 in Formula 5 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R6 in Formula 6 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R7 in Formula 7 is selected from a halogen atom; R8 and R9 in Formula 8 are each independently selected from a halogen atom; R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from a hydrogen atom or a C1-C 10 alkyl group, and the C1-C 10 alkyl group refers to an alkyl group containing 1 to 10 carbon atoms, and the halogen atom can be selected from Cl, Br, I, etc.

[0036] In some embodiments, R1 in Formula 1 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R2 in Formula 2 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R3 in Formula 3 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R4 in Formula 4 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R5 in Formula 5 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R6 in Formula 6 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 and R 17 are each independently selected from a hydrogen atom or a methyl group.

[0037] Among the above R1 to R6, they can be the same or different, and can specifically be selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group. For example, R1 to R6 can each independently be selected from a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc.

[0038] The above R7～ In R9, they can be the same or different, and specifically can be selected from a chlorine atom, a bromine atom, an iodine atom, etc.

[0039] The above-mentioned R 10 ~R 17 can be the same or different, and specifically can be selected from any one of a hydrogen atom and a C1-C 10 alkyl. For example, R 10 ~R 17 can be independently selected from a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc.

[0040] In some embodiments, A can be selected from any one of protonated 2-aminomethylpyridine, protonated 4-aminomethylpyridine, protonated 5-aminomethyl-2-chloropyridine, 2-chloro-4,4'-bipyridine, 2,2'-dichloro-4,4'-bipyridine, and 4,4'-bipyridine. Specifically, protonated 2-aminomethylpyridine is a divalent organic cation shown in Formula 3, where R3 is H; protonated 4-aminomethylpyridine is a divalent organic cation shown in Formula 1, where R1 is H; protonated 5-aminomethyl-2-chloropyridine is a divalent organic cation shown in Formula 2, where R2 is Cl; 2-chloro-4,4'-bipyridine is a divalent organic cation shown in Formula 7, where R7 is Cl; 2,2'-dichloro-4,4'-bipyridine is a divalent organic cation shown in Formula 8, where R8 and R9 are both Cl; 4,4'-bipyridine is a divalent organic cation shown in Formula 9, where R 10 、R 11 、R 12 、R 13 、R 14 、R 15 、R 16 and R 17 are all H.

[0041] In the embodiment, when X is a halogen anion, the halogen anion can be selected from at least one of Cl - 、Br - and I - . When X is a pseudohalogen anion, the pseudohalogen anion is selected from at least one of ClO4 - 、BF4 - 、PF6 - 、 formate, and acetate.

[0042] The above selection of A and X can not only enable the all-organic perovskite material of the present application to meet the requirements of the tolerance factor necessary for the perovskite crystal form, thus having good structural stability, but also have a lower band gap and a light response in the long-wave ultraviolet to visible light region. Therefore, the all-organic perovskite material of the present application can be applied in the field of narrow-bandgap optoelectronics.

[0043] In the embodiment, the band gap of the all-organic perovskite material is 1.0 - 3.88 eV. Within this band gap range, the all-organic perovskite material provided by the embodiment of the present application can have a light response in the long-wave ultraviolet to visible light region.

[0044] The second aspect of the embodiment of the present application provides a preparation method of an all-organic perovskite material, including the following steps:

[0045] Mix unprotonated A, BX, and an acidic solution for reaction treatment to obtain an all-organic perovskite material shown as ABX3.

[0046] The preparation method of the all-organic perovskite material provided by the embodiment of the present application can generate an all-organic perovskite material shown as ABX3 by mixing unprotonated A and BX with an acidic solution for reaction. This preparation method can introduce a divalent cation (A) containing a pyridine ring from the raw materials, enabling the prepared all-organic perovskite material to have a lower band gap and a light response in the long-wave ultraviolet to visible light region. In addition, this preparation method has a simple process and is suitable for industrial production, providing the possibility for the optoelectronic application of this type of novel all-organic perovskite.

[0047] Among them, the unprotonated A of the raw material is the raw material corresponding to the unprotonated divalent cation containing a pyridine ring. For example, when the divalent organic cation A in ABX3 is protonated 2-aminomethylpyridine, protonated 4-aminomethylpyridine, protonated 5-aminomethyl-2-chloropyridine, protonated 2-chloro-4,4'-bipyridine, protonated 2,2'-dichloro-4,4'-bipyridine, or protonated 4,4'-bipyridine, the unprotonated A of the raw material used in its preparation method corresponds to 2-aminomethylpyridine, 4-aminomethylpyridine, 5-aminomethyl-2-chloropyridine, 2-chloro-4,4'-bipyridine, 2,2'-dichloro-4,4'-bipyridine, or 4,4'-bipyridine.

[0048] The raw material BX is the corresponding hydrazine halide salt or hydrazine-like halide salt. For example, the hydrazine halide salt can be selected from N2H5Cl, N2H5Br, N2H5I, etc., and the hydrazine-like halide salt can be selected from N2H5ClO4, N2H5BF4, N2H5PF 6、 Hydrazine formate, hydrazine acetate, etc.

[0049] In an embodiment, the reaction between unprotonated A and BX in an acidic solution can be carried out at room temperature, for example, at a temperature of 20-30 °C for 0.5-1.5 h.

[0050] In an embodiment, the acidic solution is a hydroiodic acid solution.

[0051] The following is an illustration with specific examples.

[0052] Example 1

[0053] This example provides an all-organic perovskite material with a general chemical structure formula of ABX3; wherein, A is protonated 4-aminomethylpyridine, B is N2H5 + , and X is I - . The tolerance factor of this all-organic perovskite material is 1.04.

[0054] The preparation method of this all-organic perovskite material includes the following steps:

[0055] S11: Prepare hydrazine monohydriodide:

[0056] Disperse 5 ml of hydrazine hydrate (mass fraction 80%) into 30 ml of ethanol to form a solution, and keep the system temperature at 0 °C; then, while stirring, gradually add 12.5 ml of aqueous hydroiodic acid solution (mass fraction 57%) dropwise, stir at 0 °C for 30 minutes, filter to obtain a white / colorless powder, recrystallize the powder once with ethanol, and obtain 3.96 g of hydrazine monohydriodide after filtration and drying;

[0057] S12: Synthesize the all-organic perovskite material:

[0058] Add 216.3 mg of 4-aminomethylpyridine, 5 ml of aqueous hydroiodic acid solution (mass fraction 57%), and 320 mg of hydrazine monohydriodide to a 50 ml flask, stir at room temperature for 1 hour; then transfer to an open glass petri dish and let the solvent evaporate freely at 40 °C. After 24 hours, obtain light blue crystals; filter, rinse with acetone or ethanol, and dry to obtain the all-organic perovskite material.

[0059] Example 2

[0060] This example provides an all-organic perovskite material with a general chemical structure formula of ABX3; wherein, A is protonated 2-aminomethylpyridine, B is N2H5 + , and X is I - . The tolerance factor of this all-organic perovskite material is 1.04.

[0061] The preparation method of this all-organic perovskite material includes the following steps:

[0062] S11: Prepare hydrazine monohydriodide:

[0063] Disperse 5 mL of hydrazine hydrate (mass fraction 80%) into 30 mL of ethanol to form a solution, and maintain the system temperature at 0 °C; then, while stirring, gradually add 12.5 mL of aqueous hydroiodic acid solution (mass fraction 57%) dropwise, keep stirring at 0 °C for 30 minutes, filter to obtain a white / colorless powder, recrystallize the powder once with ethanol, and after filtration and drying, obtain 3.96 g of hydrazine monohydriodide;

[0064] S12: Synthesize all-organic perovskite material:

[0065] Add 216.3 mg of 2-aminomethylpyridine, 5 mL of aqueous hydroiodic acid solution (mass fraction 57%), and 320 mg of hydrazine monohydriodide into a 50-mL flask, stir at room temperature for 1 hour; then transfer to an open glass petri dish, allow the solvent to freely evaporate at 40 °C, and after 24 hours, obtain light blue crystals; filter and wash with acetone or ethanol, and after drying, obtain the all-organic perovskite material.

[0066] Example 3

[0067] This example provides an all-organic perovskite material with a chemical structure general formula of ABX3; wherein, A is protonated 5-aminomethyl-2-chloropyridine, B is N2H5 + , and X is I - . The tolerance factor of this all-organic perovskite material is 1.04.

[0068] The preparation method of this all-organic perovskite material includes the following steps:

[0069] S11: Prepare hydrazine monohydriodide:

[0070] Disperse 5 mL of hydrazine hydrate (mass fraction 80%) into 30 mL of ethanol to form a solution, and maintain the system temperature at 0 °C; then, while stirring, gradually add 12.5 mL of aqueous hydroiodic acid solution (mass fraction 57%) dropwise, keep stirring at 0 °C for 30 minutes, filter to obtain a white / colorless powder, recrystallize the powder once with ethanol, and after filtration and drying, obtain 3.96 g of hydrazine monohydriodide;

[0071] S12: Synthesize all-organic perovskite material:

[0072] 570.3 mg of 5-aminomethyl-2-chloropyridine, 2 mL of aqueous hydroiodic acid solution (mass fraction 57%), 1 mL of hypophosphorous acid, 2 mL of water, and 640 mg of hydrazine monohydriodide were added to a 50 mL flask and stirred at room temperature for 1 hour; then transferred to an open glass petri dish and allowed the solvent to evaporate freely at 40 °C. After 48 hours, light yellow needle-like crystals were obtained; filtered and rinsed with acetone or ethanol, and dried to obtain the all-organic perovskite material.

[0073] Comparative Example 1

[0074] This comparative example provides an all-organic perovskite material with the general chemical structure formula ABX3; where A is protonated triethylenediamine (i.e., H2DABCO, as shown in the figure below), B is NH4 + , and X is BF4 - .

[0075] The tolerance factor of this all-organic perovskite material is 0.925.

[0076]

[0077] The preparation method of this all-organic perovskite material includes the following steps:

[0078] 312 mg of triethylenediamine and 906 mg of ammonium fluoroborate were added to the inner lining of a 40 mL polytetrafluoroethylene reaction kettle, and then 4 mL of deionized water and 0.8 mL of phosphoric acid (mass fraction 85%) were added; after stirring and dissolving, it was transferred to an oven at 160 °C for hydrothermal reaction; after 72 hours, the reaction kettle was taken out, and after cooling to room temperature, it was filtered to obtain colorless particles (apparently white and translucent due to light scattering); the filter residue was washed with ethanol, air-dried and collected, which is the all-organic perovskite material.

[0079] Related test analysis:

[0080] 1. The all-organic perovskite materials provided in Examples 1 to 3 and Comparative Example 1 were respectively dissolved in a mixed solvent of N,N-dimethylformamide and water (volume ratio 1:1), stirred for 1 hour to obtain a 0.5 mol / L solution; spin-coated for 30 seconds at a rotation speed of 3000 revolutions per minute to obtain a film; then heated at 120 °C for 5 minutes to obtain a film for ultraviolet-visible absorption spectrum measurement, and the test results are as Figure 2 , 4 , 6, 8 show.

[0081] 2. The perovskite material film was prepared by the solid powder X-ray diffraction film preparation method, and the X-ray diffraction spectra of the all-organic perovskite materials provided in Examples 1 to 3 and Comparative Example 1 were measured respectively, and the test results are as Figure 1 , 3, as shown in Figures 5 and 7.

[0082] Figure 1 is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 1. Figure 3 is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 2. Figure 5 is the X-ray diffraction pattern of the all-organic perovskite material provided in Example 3. Figure 7 is the X-ray diffraction pattern of the all-organic perovskite material provided in Comparative Example 1. From Figure 1 , 3 , 5 and 7, it can be seen that the thin film has obvious diffraction peaks, indicating that the all-organic perovskite materials provided in Examples 1-3 and Comparative Example 1 have obvious crystallization characteristics.

[0083] Figure 2 is the ultraviolet-visible absorption spectrum of the all-organic perovskite material provided in Example 1. From Figure 2 it can be seen that the absorption edge of the thin film is 377 nm, which is in the long-wave ultraviolet light wavelength range, and the corresponding band gap is 3.29 eV, indicating that the all-organic perovskite material provided in Example 1 can achieve light response in the long-wave ultraviolet light band. Figure 4 is the ultraviolet-visible absorption spectrum of the all-organic perovskite material provided in Example 2. From Figure 4 it can be seen that the absorption edge of the thin film is 375 nm, which is in the long-wave ultraviolet light wavelength range, and the corresponding band gap is 3.31 eV, indicating that the all-organic perovskite material provided in Example 2 can achieve light response in the long-wave ultraviolet light band. Figure 6 is the ultraviolet-visible absorption spectrum of the all-organic perovskite material provided in Example 3. From Figure 6 it can be seen that the absorption edge of the thin film is 437 nm, which is in the blue light wavelength range, and the corresponding band gap is 2.84 eV, indicating that the all-organic perovskite material provided in Example 3 can achieve light response in the visible light band. Figure 8 is the ultraviolet-visible absorption spectrum of the all-organic perovskite material provided in Comparative Example 1. From Figure 8 it can be seen that the thin film has no light absorption in the visible light range, indicating that the all-organic perovskite material provided in Comparative Example 1 does not have light response in the visible light band.

[0084] The above examples and comparative examples show that: in the structural formula of the all-organic perovskite material of the embodiments of the present application, A has the characteristics of low band gap and light response in the long-wave ultraviolet to visible light region by selecting a divalent cation containing a pyridine ring, while A in the structural formula of the all-organic perovskite material of the comparative example does not contain a divalent cation with a pyridine ring and has a higher band gap, so it does not have light response in the long-wave ultraviolet to visible light band.

[0085] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included within the protection scope of the present application.

Claims

1. An all-organic perovskite material with a general structural formula of ABX3, characterized in that, A is a divalent cation containing a pyridine ring, B is N2H5 + , X is a halogen anion and / or a pseudohalogen anion, and the pseudohalogen anion is selected from at least one of ClO4 - , BF4 - , PF6 - , formate, acetate; The divalent cation containing a pyridine ring is selected from at least one of the following formulas 1 to 6: Formula 1 Formula 2 Formula 3 Formula 4 Formula 5 Formula 6 Among them, R1 in Formula 1 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R2 in Formula 2 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R3 in formula 3 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R4 in Formula 4 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R5 in Formula 5 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group; R6 in Formula 6 is selected from any one of a hydrogen atom, a halogen atom, and a C1-C 10 alkyl group.

2. The all-organic perovskite material according to claim 1, wherein The selection of A and X makes the tolerance factor of the all-organic perovskite material 0.8 to 1.

10.

3. The all-organic perovskite material according to claim 1, characterized in that, R1 in Formula 1 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R2 in Formula 2 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R3 in Formula 3 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R4 in Formula 4 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R5 in Formula 5 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group; R6 in Formula 6 is selected from any one of a hydrogen atom, a halogen atom, and a methyl group.

4. The all-organic perovskite material according to claim 3, wherein A is selected from protonated 2-aminomethylpyridine, protonated 4-aminomethylpyridine, and protonated 5-aminomethyl-2-chloropyridine.

5. The all-organic perovskite material according to any one of claims 1 to 4, characterized in that X is a halogen anion, and the halogen anion is selected from at least one of Cl - , Br - and I - .

6. The all-organic perovskite material according to any one of claims 1 to 4, characterized in that X is a pseudohalide anion.

7. The all-organic perovskite material according to any one of claims 1 to 4, characterized in that, The band gap of the all-organic perovskite material is 1.0 to 3.88 eV.

8. A preparation method of the all-organic perovskite material according to any one of claims 1 to 7, characterized in that, Including the following steps: Mixing unprotonated A and BX with an acidic solution for reaction treatment to obtain an all-organic perovskite material shown as ABX3.

9. The preparation method of the all-organic perovskite material according to claim 8, wherein, The temperature of the reaction treatment is 20 to 30 °C, and the time is 0.5 to 1.5 h.

10. The preparation method of the all-organic perovskite material according to claim 8, wherein The acidic solution is a hydroiodic acid solution.

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