Perovskite thin films, perovskite devices and their fabrication methods

Abstract

This invention discloses a perovskite thin film, a perovskite device, and a preparation method thereof. The preparation method of the perovskite thin film includes: coating a perovskite precursor solution onto a substrate to form a liquid film; removing at least a portion of the solvent from the liquid film using a vacuum process to form an intermediate phase film; and performing an annealing treatment to form the perovskite thin film; wherein the perovskite precursor solution contains an excess of A-site cations. The preparation method provided by this invention effectively compensates for the loss of A-site cations during the vacuum process, inhibits the formation of residual B-site cation salts, reduces device voltage loss, increases the grain size of the perovskite thin film, improves carrier transport and extraction, and increases the short-circuit current of the device; it is simple and easy to implement, low in cost, and requires no additional steps, making it suitable for the preparation of large-area perovskite thin films; it reduces the number of steps in perovskite device preparation, lowers material costs, and facilitates industrial development.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device technology, particularly to the field of solar cell technology, and especially to a perovskite thin film, a perovskite device, and a method for its preparation. Background Technology

[0002] In recent years, with the continuous deepening of research on perovskite devices, their photoelectric conversion efficiency has made rapid progress. Currently, the highest certified photoelectric conversion efficiency of small-area perovskite devices has reached 25.6%, which is widely regarded as the future and hope of the photovoltaic field.

[0003] For the fabrication of perovskite thin films and devices, solvent removal from the perovskite precursor solution is a crucial step. The main methods for solvent removal include anti-solvent methods and vacuum evacuation methods. Among these, vacuum evacuation methods are most suitable for large-area fabrication and are the most conducive to industrialization.

[0004] However, when using the vacuum process to fabricate perovskite thin films and related devices, a large amount of B-site cation salts, such as residual lead iodide, are generated. The presence of these lead iodide residues leads to numerous interface defects, causing non-radiative recombination and resulting in severe device voltage drops. Furthermore, these defects also significantly hinder carrier extraction and transport, greatly affecting the device current.

[0005] Therefore, when fabricating perovskite devices using existing technologies, a PEAI (PEAI structural formula C6H6CH2CH2NH3I) modification layer is typically introduced onto the perovskite thin film to eliminate the influence of residual lead iodide. This treatment method increases the number of steps in perovskite device fabrication and raises material costs, hindering industrial-scale development. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a perovskite thin film, a perovskite device, and a method for its fabrication.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0008] In a first aspect, the present invention provides a method for preparing a perovskite thin film, comprising:

[0009] 1) Coat the perovskite precursor solution onto the substrate to form a liquid film;

[0010] 2) At least part of the solvent in the liquid film is removed by vacuuming to form an intermediate phase film;

[0011] 3) Anneal the mesophase film to form a perovskite film;

[0012] The chemical formula of the perovskite is ABX3, and the A-site cation in the perovskite precursor solution is in excess.

[0013] Secondly, the present invention also provides a perovskite thin film prepared by the above preparation method, wherein the average particle size of the perovskite thin film is 300-600 nm and the content of the BX2 compound phase is less than 5 mol%.

[0014] Thirdly, the present invention also provides a perovskite device, including a perovskite layer, wherein the perovskite layer includes the above-mentioned perovskite thin film.

[0015] Fourthly, the present invention also provides a method for fabricating the above-mentioned perovskite device, comprising:

[0016] Provide a conductive substrate;

[0017] The step of forming a first transport layer on the surface of the conductive substrate;

[0018] The step of forming a perovskite layer on the surface of the first transport layer, wherein the perovskite layer comprises a perovskite thin film prepared by the above preparation method;

[0019] The step of forming a second transport layer on the surface of the perovskite layer; and

[0020] The step of forming an electrode layer on the surface of the second transport layer.

[0021] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least the following:

[0022] The perovskite thin film preparation method provided by this invention uses a perovskite precursor solution with an excess of A-site cations for coating and final production of the perovskite thin film. This effectively compensates for the loss of A-site cations during the perovskite thin film preparation process via the vacuum process, inhibits the formation of residual B-site cation salts, reduces device voltage loss, increases the grain size of the perovskite thin film, improves carrier transport and extraction, and increases the short-circuit current of the device. The above preparation method is simple and easy to implement, the A-site cation salts are readily available, and the cost is low. At the same time, no additional steps are required, making it suitable for the preparation of large-area perovskite thin films. By adding an excess of A-site cation salts to the perovskite precursor coating solution, the role of the PEAI modification layer on the perovskite thin film can be replaced, reducing the number of perovskite device preparation steps, lowering material costs, and facilitating industrial development.

[0023] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0024] Figure 1a This is a high-magnification electron microscope image of the surface morphology of a perovskite thin film provided in a typical comparative case of the present invention;

[0025] Figure 1b This is a low-magnification electron microscope image of the surface morphology of a perovskite thin film provided in a typical comparative case of the present invention;

[0026] Figure 2a This is a high-magnification electron microscope image of the surface morphology of a perovskite thin film provided in a typical embodiment of the present invention;

[0027] Figure 2b This is a low-magnification electron microscope image of the surface morphology of a perovskite thin film provided in a typical embodiment of the present invention;

[0028] Figure 3a This is a high-magnification electron microscope image of the surface morphology of a perovskite thin film provided in another typical embodiment of the present invention;

[0029] Figure 3b This is a low-magnification electron microscope image of the surface morphology of a perovskite thin film provided in another typical embodiment of the present invention;

[0030] Figure 4a This is a statistical distribution diagram of the particle size of the perovskite thin film provided in the comparative case of this invention;

[0031] Figure 4b This is a statistical distribution diagram of the particle size of the perovskite thin film provided in another typical embodiment of the present invention;

[0032] Figure 4c This is a statistical distribution diagram of the particle size of the perovskite thin film provided in another typical embodiment of the present invention;

[0033] Figure 5 These are performance test comparison charts of batteries using perovskite thin films provided in typical and comparative embodiments of this invention. Detailed Implementation

[0034] The inventors of this invention have discovered that in the prior art, when perovskite thin films are prepared by vacuum extraction, trace amounts of organic amine salts, such as A-site cation salts, are removed along with the solvent during the solvent removal process due to the excellent solubility of A-site cation salts in the solvent. This results in the formation of residual B-site cation salts, such as lead iodide. Even for inorganic A-site cations, the liquid film is not supersaturated during vacuum extraction, and inorganic cations are also carried away with the solvent, leading to the aforementioned phenomenon. Furthermore, for perovskite thin films prepared on nickel oxide substrates, the reducing power of trivalent nickel ions allows them to react with organic amine salts to generate halogens or pseudohalogens and organic amines, further leading to the formation of residual BX2 compound phases. These residual BX2 compound phases constitute defects in the perovskite thin film, causing severe device voltage drops and affecting carrier transport and extraction.

[0035] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The main objective of this invention is to improve the vacuum pumping process, thereby reducing lead iodide residue in the perovskite thin film prepared by the pumping method, replacing the role of the PEAI modification layer on top of the perovskite film, reducing the number of steps in the perovskite device fabrication process, and overcoming the shortcomings of the prior art. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0037] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component or method step from another that has the same name, and do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0038] This invention provides a method for preparing perovskite thin films. This method is based on a vacuuming process and specifically includes the following steps:

[0039] 1) Coat the perovskite precursor solution onto the substrate to form a liquid film.

[0040] 2) At least part of the solvent in the liquid film is removed by vacuuming to form an intermediate phase film.

[0041] 3) The mesophase film is annealed to form a perovskite film.

[0042] The chemical formula of the perovskite is ABX3, and the A-site cation in the perovskite precursor solution is in excess.

[0043] In some embodiments, in step 1), the A-site cation is in stoichiometric excess of 1-10 mol%.

[0044] In some embodiments, the perovskite precursor solution may include AX salt or BX2 salt.

[0045] In some embodiments, the concentration of the AX salt can be 0.8-1.5 mol / L.

[0046] In some embodiments, the concentration of the BX2 salt can be 0.8-1.5 mol / L.

[0047] In some embodiments, A represents an organic amine cation and / or an alkali metal cation, preferably including CH3NH3. + NH2CH=NH2 + Cs + and Rb + B can represent any one or more of the following: B can represent any one or more of the cations Pb or Sn; X can represent the anion of a halogen or pseudohalogen; the halogen can include any one or more of Cl, Br, and I; and the pseudohalogen can include any one or more of CN, SCN, OCN, and SeCN groups.

[0048] As some typical application examples, in step 1), the solute in the perovskite precursor solution is generally the perovskite material, and the stoichiometric composition of the perovskite material is generally ABX3, where A represents CH3NH3. + (MA), NH2CH=NH2 + One or more of (FA), Cs or Rb; B represents one or more of Pb or Sn; X represents a halogen or pseudohalogen; halogens are selected from Cl, Br or I; pseudohalogens are selected from CN, thiocyanate (SCN), oxocyanate (OCN), or selenocyanate (SeCN), etc.

[0049] In step 1), the excess of A-site cations can refer to the addition of a certain molar ratio of A-site cation salts to the stoichiometric composition of the perovskite material. The solvent of the perovskite precursor solution is generally a mixed solvent of N,N-dimethylformamide and N-methylpyrrolidone, with a volume ratio of, for example, 4:1. Furthermore, the A-site cation salts include, but are not limited to, hydroiodates, hydrobromates, or hydrochlorides of FA, MA, Cs, and Rb. The coating can be performed using spin coating or coating processes, including but not limited to these, and other processes such as spraying are also possible.

[0050] In some embodiments, the vacuum level of the evacuation process in step 2) can be 10-500 Pa, and the time can be 60-120 s. For step 2), the evacuation time is generally 60-120 s, depending on the concentration of the precursor solution and the size of the device area. The main purpose is to remove most of the solvent and form an intermediate phase film.

[0051] In some implementations, step 3) may be a multi-stage annealing process.

[0052] In some embodiments, the multi-stage annealing process may specifically include: first annealing at 80-120°C for 1-2 minutes, and then annealing at 130-150°C for 10-20 minutes.

[0053] For step 3), the segmented annealing generally involves first annealing the mesophase film at 100°C for 1-2 minutes, and then annealing it at 130-150°C for 15 minutes. The purpose is to enable the perovskite film to achieve a better phase transformation.

[0054] This invention also provides a perovskite film prepared by the above method, wherein the average particle size of the perovskite film is 300-600 nm, and the content of the BX2 compound phase is less than 5 mol%. The thickness of the perovskite film can also be in the range of 300-600 nm. Referring to Figures 2-4, this invention adopts a method of adding a certain molar ratio of A-site cation salt to the perovskite precursor solution, which can effectively compensate for the loss of A-site cations, especially organic amine cations, during the preparation of the perovskite film. From the SEM surface morphology of the prepared perovskite film, the generation of lead iodide residue in the perovskite film is effectively suppressed, and it is beneficial to the growth of perovskite film grains, resulting in a higher quality perovskite film.

[0055] This invention also provides a perovskite device, including a perovskite layer and a structural layer. The perovskite layer includes the perovskite thin film provided in any of the above embodiments. The structural layer cooperates with the perovskite layer to form a device. The structural layer can be a structural layer in existing perovskite devices, such as the multilayer structure described below, or a special structural layer designed by a person skilled in the art for other purposes. As long as photoelectric conversion is achieved using the above-mentioned perovskite thin film, it is within the protection scope of this invention, and will not be elaborated further here.

[0056] In some embodiments, the perovskite device may include a perovskite cell, particularly a perovskite solar cell.

[0057] In some embodiments, the structural layer may include a conductive substrate, a first transport layer, a second transport layer, and an electrode layer arranged sequentially, wherein the first transport layer and the second transport layer have opposite conductivity types, and the perovskite layer is disposed between the first transport layer and the second transport layer. The perovskite device can be a positive or negative device. For example, a positive device has a structure consisting of a conductive substrate, an electron transport layer (as the first transport layer), a perovskite layer, a hole transport layer (as the second transport layer), and a metal electrode arranged sequentially; a negative device has a structure consisting of a conductive substrate, a hole transport layer (as the first transport layer), a perovskite layer, an electron transport layer (as the second transport layer), and a metal electrode arranged sequentially.

[0058] The upright structure can be: a conductive substrate / electron transport layer / perovskite layer / hole transport layer / metal electrode. The material and thickness of each layer can be, for example: the conductive substrate is one of FTO conductive glass, ITO conductive glass, FTO conductive plastic, or ITO conductive plastic, where the FTO thickness is approximately 500 nm and the ITO thickness is approximately 300-400 nm; the electron transport layer is any one or a combination of several of TiO2, ZnO2, and SnO2, with a thickness of approximately 10-50 nm. The perovskite layer can be, for example, CsFAMAPbI3, with a thickness of 300–1000 nm; the hole transport layer is any one or more combinations of Spiro-OMeTAD (2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirodifluorene), PEDOT:PSS, P3HT, PTAA, or PCDTBT, with a thickness of 300–600 nm; the metal electrode is any one of Ag, Al, or Au, with a thickness of approximately 100–200 nm.

[0059] The inverted structure can be: a conductive substrate / hole transport layer / perovskite layer / electron transport layer / metal electrode, wherein the material and thickness of each layer are as follows: the conductive substrate is one of FTO conductive glass, ITO conductive glass, FTO conductive plastic, and ITO conductive plastic, wherein the FTO thickness is approximately 500 nm, the ITO thickness is approximately 300-400 nm, and the hole transport layer is NiO. x The thickness is approximately 15-40 nm; the perovskite layer, for example, is CsFAMAPbI3, with a thickness of 300-1000 nm; the electron transport layer is PCBM or TiO2. x SnO2 or ZnSnO x Any one of the following, with a thickness of approximately 20-50 nm, and the metal electrode is any one or more combinations of Ag, Al, or Au, with a thickness of approximately 100-200 nm.

[0060] The present invention also provides a method for fabricating the above-mentioned perovskite device, comprising the following steps:

[0061] Provide a conductive substrate.

[0062] The step of forming a first transport layer on the surface of the conductive substrate.

[0063] The step of forming a perovskite layer on the surface of the first transport layer, wherein the perovskite layer includes a perovskite thin film prepared by the perovskite thin film preparation method provided in any of the above embodiments.

[0064] The step of forming a second transport layer on the surface of the perovskite layer; and

[0065] The step of forming an electrode layer on the surface of the second transport layer.

[0066] In some embodiments, the conductive substrate may be prepared by any one or a combination of two or more of the physical vapor deposition, evaporation and sputtering methods.

[0067] In some embodiments, the first transport layer and / or hole transport layer may be prepared by any one or a combination of two or more of spin coating, spray coating and blade coating methods.

[0068] In some embodiments, the electrode can be prepared using vapor deposition and / or sputtering methods.

[0069] As some specific implementation schemes, the preparation methods of each layer of the perovskite solar cell can be as follows: the conductive substrate is prepared by physical vapor deposition, evaporation or sputtering; the electron transport layer and the hole transport layer are prepared by any one of spin coating, spraying or scraping; the perovskite layer is prepared by spin coating plus degassing; and the metal electrode is prepared by vacuum evaporation or vacuum sputtering.

[0070] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0071] Unless otherwise specified, the equipment, materials and reagents used in the following examples can be obtained through conventional commercial channels.

[0072] Example 1

[0073] This embodiment illustrates a process for preparing perovskite thin films using a vacuuming technique, as detailed below:

[0074] 1) Based on the stoichiometric ratio of the perovskite material, an additional 1 mol% of FAI was added to prepare a perovskite precursor solution with excess FA cations. The B-site cation salt in the solution was lead iodide with a concentration of 1.2 mol / L, and the solvent was a mixed solvent of N,N-dimethylformamide and N-methylpyrrolidone in a volume ratio of 4:1.

[0075] 2) Spin-coat the perovskite coating liquid onto the substrate to form a uniform liquid film. The spin-coating speed is 2000-2500 rpm, the acceleration is 1000 rpm / s, and the time is about 8-10s.

[0076] 3) Place the liquid film in a vacuum device and evacuate it to a vacuum of 150 Pa for 90 seconds to remove most of the solvent and form a brown mesophase film.

[0077] 4) The perovskite was first placed on a hot plate at 100°C and annealed for 1 minute, and then placed on a hot plate at 150°C and annealed for 15 minutes.

[0078] Examples 2-5

[0079] This embodiment is basically the same as Embodiment 1, except that:

[0080] The excess of FA cations in the perovskite precursor solution was increased by 1 mol% to 5 mol% sequentially, corresponding to Examples 2-5 in ascending order.

[0081] The surface morphologies of the perovskite films prepared in Examples 3 and 5 are as follows: Figure 2a , Figure 2b and Figure 3a , Figure 3b As shown, there is significantly less residual lead iodide phase on its surface.

[0082] Comparative Example 1

[0083] This embodiment illustrates a process for preparing perovskite thin films using a vacuuming technique, as detailed below:

[0084] 1) The perovskite precursor solution was prepared strictly according to the stoichiometric ratio of the perovskite material. The concentration of the A-site cation FAI was 1.2 mol / L, the B-site cation salt in the solution was lead iodide with a concentration of 1.2 mol / L, and the solvent was a mixed solvent of N,N-dimethylformamide and N-methylpyrrolidone in a volume ratio of 4:1.

[0085] The perovskite thin film was prepared using the same subsequent process as in Example 1, and the resulting surface morphology is as follows. Figure 1a and Figure 1b As shown, the surface has several large residual lead iodide phases.

[0086] Performance testing

[0087] Perovskite solar cells were fabricated using the methods provided in Comparative Examples and Examples 1-5 (the structures and thicknesses of each layer of the perovskite solar cells fabricated in both examples were identical; the anode of the fabricated perovskite solar cells was FTO with a thickness of approximately 400 nm, the hole transport layer was nickel oxide with a thickness of approximately 20-30 nm, the active layer was perovskite with a thickness of approximately 300-600 nm, the electron transport layer was PCBM with a thickness of approximately 40-60 nm, and the cathode was silver with a thickness of approximately 80-120 nm). These were designated as Comparative Example Solar Cells (their particle size distributions are shown in Figure 1-5). Figure 4a (as shown) and Examples 1-5, wherein the particle size distribution of Examples 3 and 5 is compared with that of the comparative examples. Figure 4b , Figure 4c As shown in the figure, the performance of the corresponding perovskite solar cells was tested, and the performance is shown in Table 1. A comparison graph of the device performance of the comparative example and the best-performing Example 3 is also provided, as shown in the figure. Figure 5 As shown.

[0088] Table 1. Performance Comparison of Example Battery and Comparative Battery

[0089]

[0090] Example 6

[0091] This embodiment is basically the same as Embodiment 1, except that:

[0092] In the perovskite precursor solution, CsBr is selected as the cation salt at the A site, and SnBr2 is selected as the cation salt at the B site.

[0093] The concentration of BX2 salt was 0.8 mol / L, the vacuum degree of the gas extraction process was 500 Pa, and the time was 120 s.

[0094] The annealing process involves first annealing at 80°C for 2 minutes, and then annealing at 150°C for 10 minutes.

[0095] Example 7

[0096] This embodiment is basically the same as Embodiment 1, except that:

[0097] In the perovskite precursor solution, MABr is selected as the cation salt at the A site, and SnI2 is selected as the cation salt at the B site.

[0098] The concentration of BX2 salt was 1.3 mol / L, the vacuum degree of the gas extraction process was 10 Pa, and the time was 60 s.

[0099] Anneal at 120℃ for 1 min, then anneal at 130℃ for 20 min.

[0100] Neither the perovskite films prepared in Examples 6 and 7 showed a large amount of residual BX2 compound phase.

[0101] Based on the above test results, it is clear that, compared with the prior art, the method for preparing perovskite thin films by preparing a perovskite precursor coating solution with an excess A-site cation salt ratio provided in this embodiment of the invention can compensate for the loss of organic amine salts during the preparation of perovskite thin films by the vacuum method, thereby effectively suppressing the generation of residual lead iodide in the perovskite thin film, reducing defects in the perovskite thin film, and thus reducing the voltage drop of the perovskite device. Simultaneously, the morphology of the perovskite thin film is also improved, the grain size increases, and the short-circuit current of the device also increases, thereby effectively improving the performance of the perovskite device. Furthermore, the perovskite thin film preparation method provided by this invention is simple, easy to implement, and low in cost, suitable for widespread application, and equally feasible for the preparation of large-area perovskite thin films. Moreover, by adding an excess A-site cation salt to the perovskite precursor coating solution, the role of the PEAI modification layer on top of the perovskite can be replaced, reducing the perovskite device preparation steps and facilitating industrial development.

[0102] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite thin film, comprising: 1) Coat the perovskite precursor solution onto the substrate to form a liquid film; 2) At least a portion of the solvent in the liquid film is removed by vacuuming, forming an intermediate phase film; 3) Anneal the mesophase film to form a perovskite film; The perovskite is characterized by having the chemical formula ABX3, and the perovskite precursor solution comprising AX salt and BX2 salt, wherein the X halogen is selected from Cl, Br, I, or pseudohalogen; based on the stoichiometric ratio of the perovskite material, the perovskite precursor solution is prepared in excess of the A-site cation ratio, thereby suppressing the generation of residual B-site cation salt in the formed perovskite film, resulting in the content of the BX2 compound phase in the formed perovskite film being less than 5 mol.

2. The preparation method according to claim 1, characterized in that, In step 1), the A-site cation is in stoichiometric excess of 1-10 mol%.

3. The preparation method according to claim 1, characterized in that, The concentration of the AX salt is 0.8-1.5 mol / L; And / or, the concentration of the BX2 salt is 0.8-1.5 mol / L.

4. The preparation method according to claim 1, characterized in that, A represents organic amine cations and / or alkali metal cations, including CH3NH3. + NH2CH=NH2 + Cs + and Rb + Any one or more of the following; B represents any one or a combination of two of the cations Pb or Sn; The pseudohalogen includes any one or a combination of two or more of CN, SCN, OCN, and SeCN groups.

5. The preparation method according to claim 1, characterized in that, In step 2), the vacuum degree of the pumping process is 10-500 Pa, and the time is 60-120 s.

6. The preparation method according to claim 1, characterized in that, In step 3), the annealing process is a multi-stage annealing process; The multi-stage annealing process specifically includes: first annealing at 80-120℃ for 1-2 minutes, and then annealing at 130-150℃ for 10-20 minutes.

7. A perovskite thin film prepared by the preparation method according to any one of claims 1-6, characterized in that, The perovskite film has an average particle size of 300-600 nm and a BX2 compound phase content of less than 5 mol.

8. A perovskite device, comprising a perovskite layer, characterized in that, The perovskite layer comprises the perovskite thin film of claim 7.

9. The perovskite device according to claim 8, characterized in that, The perovskite device includes a conductive substrate, a first transport layer, a perovskite layer, a second transport layer, and an electrode layer arranged sequentially, wherein the first transport layer and the second transport layer have opposite conductivity types.

10. The perovskite device according to claim 9, characterized in that, The perovskite device includes a conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode arranged sequentially along a predetermined direction.

11. The perovskite device according to claim 9, characterized in that, The perovskite device includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode arranged sequentially along a predetermined direction.

12. The method for fabricating the perovskite device according to any one of claims 8-11, characterized in that, include: Provide a conductive substrate; The step of forming a first transport layer on the surface of the conductive substrate; The step of forming a perovskite layer on the surface of the first transport layer, wherein the perovskite layer comprises a perovskite thin film prepared by the preparation method according to any one of claims 1-7; The step of forming a second transport layer on the surface of the perovskite layer; as well as The step of forming an electrode layer on the surface of the second transport layer.

13. The preparation method according to claim 12, characterized in that, The conductive substrate is prepared by any one or a combination of two or more of the physical vapor deposition, evaporation and sputtering methods. And / or, the first transport layer and / or the second transport layer are prepared by any one or a combination of two or more of the spin coating, spray coating and blade coating methods; And / or, the electrode layer is prepared using vapor deposition and / or sputtering methods.

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