Large-area perovskite single crystal film, preparation method and application thereof

Abstract

This invention provides a large-area perovskite single-crystal film, its preparation method, and its applications, belonging to the field of semiconductor technology. The general structural formula of the large-area perovskite single-crystal film is: A m B n X z In the formula, A is an imidazole positive ion, m=1~3; B is a metal cation, n=1~2; and X is a halide anion, z=3~9. The preparation method of a large-area perovskite single-crystal film includes: mixing a metal halide precursor solution and a halide imidazole precursor solution; preheating a conductive substrate on a hot stage; drop-coating the mixed solution onto the conductive substrate for in-situ growth; annealing; stimulating any corner of the conductive substrate surface with a sharp object; and cooling to obtain a large-area perovskite single-crystal film, which can be used to prepare optoelectronic devices. This invention provides perovskite materials with specific compositions and combines in-situ growth with crystal nucleus control to prepare high-quality, large-area single-crystal films without obvious grain boundaries and defects. The process is simple and conducive to industrial application.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, and specifically relates to large-area perovskite single crystal films, their preparation methods, and applications. Background Technology

[0002] Perovskite, as a new generation of optoelectronic materials, has shown great potential for application in optoelectronic devices such as lasers, photodetectors, and solar cells due to its excellent optoelectronic properties, such as high absorption coefficient, long exciton diffusion distance, high carrier mobility, and low exciton binding energy. In practical applications, it is necessary to fabricate perovskite thin films with adjustable thickness to avoid carrier loss while ensuring sufficient light absorption. However, there are factors restricting the development of perovskite in optoelectronic devices, mainly including two aspects: (1) Crystal morphology of perovskite thin films. The crystal morphology of perovskite thin films has a decisive influence on photoelectric properties. Its crystal morphology is mainly divided into two categories: polycrystalline films and monocrystalline films. Polycrystalline films are composed of a large number of grains and grain boundaries. They have the advantages of simple preparation process and low cost, and are the mainstream morphology of perovskite thin films. However, they have problems such as high grain boundary defect density and poor stability. Monocrystalline films have advantages such as low grain boundary defect density, high carrier mobility, low voltage loss, resistance to ion migration, resistance to damp heat aging, and more uniform band structure. However, they are limited by preparation cost and process complexity, making it difficult to promote them on a large scale.

[0003] (2) Large-area perovskite thin films are difficult to prepare. Especially for single-crystal films, stress cracks are prone to occur during epitaxy when preparing large-area perovskite thin films.

[0004] Spatial confinement has proven to be an effective method for preparing perovskite single-crystal films with controllable thickness. It restricts the solution thickness by using a narrow slit (typically 10 μm to 50 μm) formed by the upper and lower substrates, reducing the number of random nucleation sites in the solution and forcing the crystal to grow along a two-dimensional axis within the confined space. This method allows for flexible adjustment of the perovskite thickness within a geometrically confined space. However, existing spatial confinement methods have several problems. On the one hand, they are mainly used for growing MAPbX3-based perovskite single-crystal films, and the resulting films are easily broken under external forces, making integration with optoelectronic devices difficult and posing significant challenges to subsequent device fabrication, such as the electron transport layer and hole transport layer in solar cells. On the other hand, the grown perovskite single-crystal films exhibit high surface defect state density, greatly affecting the performance characterization of subsequent devices. Furthermore, current spatial confinement methods based on solution evaporation suffer from nucleation at solution edges due to solvent evaporation caused by temperature increases, leading to solute competition at different nuclei and reducing the success rate of large-size crystal growth.

[0005] Therefore, in order to meet the needs of most optoelectronic device applications, the preparation of large-area, high-quality perovskite single crystal films is an urgent technical problem to be solved. Summary of the Invention

[0006] Therefore, the present invention aims to provide large-area perovskite single crystal films, their preparation methods and applications, in order to solve at least one technical problem in the background art.

[0007] This invention is implemented as follows: The first aspect of this invention provides a method for preparing a large-area perovskite single crystal film, the method comprising the following steps: The conductive substrate undergoes surface cleaning treatment; Metal halides and halogenated imidazoles are dissolved in organic solvents to prepare metal halide precursor solutions and halogenated imidazole precursor solutions, and then mixed in a predetermined ratio to obtain perovskite precursor solutions. The conductive substrate is placed on a hot stage for preheating. The perovskite precursor solution is drop-coated onto the conductive substrate for in-situ growth. Then, annealing is performed. After annealing for a period of time, crystal nucleation control is performed. After annealing, the temperature is cooled to room temperature through a program to obtain a large-area perovskite single crystal film. The general structural formula for large-area perovskite single-crystal film materials is: A m B n X z In the formula, A is an imidazole positive ion, m is its atomic number, m=1~3; B is a metal cation, n is its atomic number, n=1~2; X is a halide anion, z is its atomic number, z=3~9; The general structural formula for A is: or R is an alkyl or alkylamine group; The step of nucleus control is as follows: using a sharp object to stimulate any corner of the upper surface of the conductive substrate, causing it to nucleate at the corner and grow in a highly oriented manner along the diagonal direction.

[0008] Furthermore, the A m B n X z If the cation is ABX3, then B is a divalent metal cation, and B is selected from Pb. 2+ Sn 2+ 、Ge 2+ Zn 2+ Cd 2+ or Cu 2+ The molar ratio of metal halide to halogenated imidazole is 1:0.9~1.2. Or, the A m B n X zIf the cation is A3B2X9, then B is a trivalent metal cation, and B is selected from Sb. 3+ Bi 3+ In 3+ Eu 3+ or Tb 3+ The molar ratio of metal halide to halogenated imidazole is 1:1.3~1.7. Or, the A m B n X z If the cation is AB2X3, then B is a monovalent metal cation, and B is selected from Cu. + Ag + or In + The molar ratio of metal halide to halogenated imidazole is 2:0.8~1.2.

[0009] Furthermore, A is selected from any one of equations (1) to (5): .

[0010] The concentration of the metal halide precursor solution is 0.5 mmol / mL to 3 mmol / mL; the concentration of the halogenated imidazole precursor solution is 0.5 mmol / mL to 5 mmol / mL.

[0011] Furthermore, the temperature of the heating stage is 60℃~150℃, the annealing time is 6h~48h, and the cooling rate is 1.5℃ / h~17.0℃ / h.

[0012] Furthermore, the organic solvent is selected from at least one of amide solvents, sulfoxide solvents, sulfone solvents, ester solvents, hydrazide solvents, nitrile solvents, alcohol solvents, ketone solvents, pyridine, and tetrahydrofuran.

[0013] The second aspect of the present invention provides a large-area perovskite single crystal film prepared by the above-described method.

[0014] A third aspect of the present invention provides the application of the above-mentioned large-area perovskite single crystal film, wherein the large-area perovskite single crystal film is used to fabricate optoelectronic devices.

[0015] A fourth aspect of the present invention provides an X-ray detector, the X-ray detector comprising a conductive substrate, a perovskite layer and electrodes stacked sequentially from bottom to top; the perovskite layer is a large-area perovskite single crystal film as described above; The steps for fabricating an X-ray detector are as follows: peel off 1 / 8 to 1 / 4 of a large-area perovskite single crystal film to expose the conductive layer of the conductive substrate, and then deposit an electrode with a thickness of 100 nm to 150 nm on the surface of the large-area perovskite single crystal film and the exposed conductive substrate to obtain the X-ray detector.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides perovskite materials with specific components and combines in-situ growth with crystal nucleus control to prepare high-quality, large-area single-crystal films without obvious grain boundaries and defects. The process is simple and conducive to industrial application.

[0017] 2. The preparation method provided by this invention uses in-situ growth at a specific temperature and achieves controllable crystal nuclei to prepare large-area perovskite single crystal films. This preparation method is low in cost, simple to operate, mild in preparation conditions, and environmentally friendly, solving the problems of high equipment cost and harsh preparation conditions of chemical vapor deposition.

[0018] 3. The thickness of the large-area perovskite single crystal film prepared by this invention can be controlled within a certain range, and theoretically the area of ​​the single crystal film has no obvious limitation and can increase infinitely with the increase of the area of ​​the conductive substrate. Furthermore, the prepared single crystal film has no obvious grain boundaries and defects and has high quality.

[0019] 4. The large-area perovskite single crystal film prepared by this invention has good application prospects in optoelectronic devices, especially in the field of X-ray detection. This single crystal film can be grown on a variety of conductive substrates and is easy to integrate on TFT array circuit boards. It is suitable for a variety of optoelectronic devices and has significant effects in X-ray array imaging, showing great potential.

[0020] 5. The X-ray detector prepared by the large-area perovskite single crystal film of the present invention has high sensitivity and excellent dark current drift stability during long-term use, and excellent working stability under high radiation dose for a long time. Attached Figure Description

[0021] Figure 1 These are photographs of the crystal growth at different times during the preparation of single-crystal films in Examples 1 to 9 of this invention; Figure 2 These are physical images of the final state of the single-crystal films prepared in Examples 1 to 9 of this invention; Figure 3 This is a photograph of the PMIMPbBr3 single crystal film grown on a large area of ​​10cm×10cm FTO glass in Embodiment 1 of the present invention. Figure 4 This is a physical image of the PMIMPbBr3 single crystal film prepared in Example 1 of the present invention integrated on a TFT array circuit board; Figure 5 The image shows the XRD pattern of the PMIMPbBr3 single crystal film prepared in Example 1 of this invention. Figure 6 The image shows the morphology of the PMIMPbBr3 single crystal film prepared in Example 1 of this invention as observed under an atomic force microscope. Figure 7 The image shows the morphology of the PMIMPbBr3 single crystal film prepared in Example 1 of this invention as observed under a polarizing microscope. Figure 8 This is a photograph of the PMIMPbI3 single crystal film grown on a large area of ​​10cm×10cm FTO glass in Embodiment 2 of the present invention. Figure 9 The image shows the XRD pattern of the PMIMPbI3 single crystal film prepared in Example 2 of this invention. Figure 10 The image shows the morphology of the PMIMPbI3 single crystal film prepared in Example 2 of this invention as observed by an atomic force microscope. Figure 11 The image shows the XRD pattern of the PMIMSnI3 single crystal film prepared in Example 3 of this invention. Figure 12 The XRD pattern of the (EMIM)3Bi2I9 single crystal film prepared in Example 4 of this invention; Figure 13 The XRD pattern of the (EMIM)3Bi2Br3I6 single crystal film prepared in Example 5 of this invention; Figure 14 This is a physical image of the (EMIM)3Bi2I9 single crystal film prepared in Embodiment 5 of the present invention integrated on a TFT array circuit board; Figure 15 This is an X-ray array imaging effect of the (EMIM)3Bi2Br3I6 single crystal film prepared in Example 5 of the present invention; Figure 16 The XRD pattern of the (EMIM)3Sb2Br9 single crystal film prepared in Example 6 of this invention; Figure 17 The XRD pattern of the (EMIM)3Sb2I9 single crystal film prepared in Example 7 of this invention; Figure 18 The XRD pattern of the (EMIM)3In2I9 single crystal film prepared in Example 8 of this invention; Figure 19 The images show the physical images of the four perovskite films prepared in Comparative Example 1. Figure 20 The XRD patterns of the four perovskite films prepared in Comparative Example 1 are shown. Figure 21 This is a schematic diagram of the structure of the X-ray detector obtained in Embodiment 10 of the present invention; Figure 22 The current density-time curves of the X-ray detector X-I obtained in Example 10 of this invention under different bias voltages are shown. Figure 23The current density-time curves of the X-ray detector X-II obtained in Example 10 of this invention under different bias voltages are shown. Figure 24 The current density-time curves of the X-ray detector X-III obtained in Example 10 of this invention under different bias voltages are shown. Figure 25 The current density-time curves of the X-ray detector X-Ⅳ under different bias voltages obtained in Example 10 of the present invention are shown. Figure 26 The following are current density-time diagrams of four sets of X-ray detectors obtained in Example 10 of the present invention under different bias voltages and different dose rates. Figure 27 This is a graph showing the dark current density of four X-ray detectors prepared in Embodiment 10 of the present invention as a function of time in the dark state. Figure 28 This refers to the current density-time of the X-ray detector X-I irradiated over a long period of time by the X-ray detector prepared in Embodiment 10 of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] The perovskite involved in this invention The preparation method of large-area perovskite single crystal films includes steps S1 to S3.

[0024] S1. The conductive substrate undergoes surface cleaning treatment; The conductive substrate is made of FTO glass, ITO glass or TFT array circuit board. Before use, it is ultrasonically cleaned with deionized water and anhydrous ethanol for 15 min to 30 min respectively, dried with nitrogen, and finally cleaned with a plasma cleaner.

[0025] S2, metal halide and halogenated imidazole are dissolved in an organic solvent to prepare a metal halide precursor solution and a halogenated imidazole precursor solution, and then mixed in a predetermined ratio to obtain a perovskite precursor solution. Metal halides are composed of metal cations B (Pb) 2+ Sn 2+ 、Ge 2+ Zn 2+ Cd 2+ Cu 2+ Sb 3+ Bi 3+ In 3+ Eu 3+ 、Tb 3+ Cu +Ag + In + ) and halide anion X (Cl - ,Br - I - (It can be obtained by any combination.)

[0026] When the metal cation in the metal halide is divalent, the molar ratio of metal halide to halogenated imidazole is 1:0.9~1.2; when the metal cation in the metal halide is trivalent, the molar ratio of metal halide to halogenated imidazole is 1:1.3~1.7; when the metal cation in the metal halide is monovalent, the molar ratio of metal halide to halogenated imidazole is 2:0.8~1.2; the concentration of the metal halide precursor solution is 0.5mmol / mL~3mmol / mL.

[0027] Halogenated imidazoles are formed by the reaction of imidazole positive ion A with halogen anion X (Cl... - ,Br - I - The concentration of the halogenated imidazole precursor solution is 0.5 mmol / mL to 5 mmol / mL; A is selected from any one of formulas (1) to (5): 1-propyl-3-methylimidazole, abbreviated as PMIM + ; 1-Ethyl-3-methylimidazole, abbreviated as EMIM + ; 1-Butyl-3-methylimidazole, abbreviated as BMIM + ; 1-Hexyl-3-methylimidazole, abbreviated as HMIM + ; 1-Aminoethyl-3-methylimidazole, abbreviated as AMIM + .

[0028] The organic solvent can be any one or a mixture of amide solvents, sulfoxide solvents, sulfone solvents, ester solvents, hydrazide solvents, nitrile solvents, alcohol solvents, ketone solvents, pyridine, and tetrahydrofuran, all of which are ultra-dry solvents; the optimal choices are ultra-dry dimethyl sulfoxide (DMSO) and ultra-dry N,N-dimethylformamide (DMF).

[0029] S3. The conductive substrate is placed on a hot stage and preheated to 60℃~150℃. The perovskite precursor solution obtained by mixing the two precursors is drop-coated onto the conductive substrate for in-situ growth. After the growth is completed, annealing is performed for 6h~48h. After annealing for a period of time, crystal nucleation control is performed. After annealing, the temperature is reduced to room temperature at a cooling rate of 1.5℃ / h~17.0℃ / h to obtain a large-area perovskite single crystal film. The steps for controlling the crystal nuclei are as follows: after annealing for a period of time, some organic solvents evaporate, and a sharp object (such as a needle tip) is used to stimulate any corner of the upper surface of the conductive substrate, so that it nucleates in the corner and grows in a highly oriented manner along the diagonal direction.

[0030] The general structural formula for large-area perovskite single-crystal film materials is: A m B n X z In the formula, A is an imidazole positive ion, m is its atomic number, m=1~3; B is a metal cation, n is its atomic number, n=1~2; X is a halide anion (Cl). - ,Br - I - (at least one of them), z is the number of its atoms, z = 3~9; The general structural formula for A is: or R is an alkyl or alkylamine group.

[0031] Specifically, the A m B n X z If the cation is ABX3, then B is a divalent metal cation, and B is selected from Pb. 2+ Sn 2+ 、Ge 2+ Zn 2+ Cd 2+ or Cu 2+ ; Or, the A m B n X z If the cation is A3B2X9, then B is a trivalent metal cation, and B is selected from Sb. 3+ Bi 3+ In 3+ Eu 3+ or Tb 3+ ; Or, the A m B n X z If the cation is AB2X3, then B is a monovalent metal cation, and B is selected from Cu. + Ag + or In + .

[0032] This invention discloses a large-area perovskite single-crystal film prepared by a nucleus-controlled in-situ growth method using specific perovskite materials. This film exhibits adjustable thickness, adapting to the requirements of optoelectronic device fabrication within a certain range. Therefore, it can be used to fabricate optoelectronic devices, including but not limited to perovskite solar cells and perovskite photodetectors. The thickness of the perovskite single-crystal film prepared by the method described above is adjustable from 10 μm to 300 μm, with a smooth and uniform surface and theoretically infinitely expansive film area.

[0033] Taking an X-ray detector as an example, it includes a conductive substrate, a perovskite layer, and electrodes stacked sequentially from bottom to top; the perovskite layer is the aforementioned large-area perovskite single crystal film; the steps for fabricating the X-ray detector are as follows: peeling off 1 / 8 to 1 / 4 of the large-area perovskite single crystal film to expose the conductive layer of the conductive substrate, and then depositing electrodes with a thickness of 100nm to 150nm on the surface of the large-area perovskite single crystal film and the exposed conductive substrate to obtain the X-ray detector, which exhibits good photoelectric response characteristics.

[0034] Example 1 The preparation method of perovskite single crystal film PMIMPbBr3 provided by this invention includes the following specific steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.734 g) of lead bromide (PbBr2), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 3 mmol (0.6153 g) of 1-propyl-3-methylimidazolium bromide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 3 mmol / mL; S3. Preparation of PMIMPbBr3 single crystal film: The above metal halide precursor and halide imidazole precursor solution were mixed at a molar ratio of 1:1 and set aside. The pretreated FTO glass (1.5cm × 1.5cm) was placed on a hot stage at 135℃ for preheating. Then, 125μL of the prepared solution was dropped onto the FTO glass using a pipette for in-situ growth. After the growth was completed, annealing was performed. After annealing for 15 minutes, a corner of the FTO glass surface was stimulated with the tip of a 2mL syringe needle (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows highly oriented along the diagonal direction from the point where the crystal nucleus is generated. The general growth process is as follows: Figure 1As shown in Figure a, after surface growth, the sample is annealed for 24 hours, then cooled to room temperature at a programmed rate of 4.5℃ / h before being removed. The prepared PMIMPbBr3 single crystal film is shown below. Figure 2 As shown in Figure a, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0035] It is worth noting that the conductive substrate for PMIMPbBr3 single crystal film can also be other growth substrates, such as ITO glass or TFT array circuit boards. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs. Figure 3 A large-area PMIMPbBr3 single crystal film was obtained by in-situ growth using 10cm×10cm FTO glass as a conductive substrate. Figure 4 It is a large-area PMIMPbBr3 single crystal film integrated on a TFT array circuit board.

[0036] XRD tests were performed on the PMIMPbBr3 single crystal film, and the results are as follows: Figure 5 As shown, it exhibits a very strong overtone diffraction peak. Atomic force microscopy (AFM) testing yielded the following results: Figure 6 As shown, the surface smoothness of the PMIMPbBr3 single crystal film is at the nanometer level. Figure 7 Image a shows the morphology of a PMIMPbBr3 single-crystal film prepared using FTO glass as a conductive substrate under a polarizing microscope. Figure 7 Image b shows the morphology of a PMIMPbBr3 single crystal film prepared using a TFT array as the conductive substrate under a polarizing microscope. The polarizing microscope reveals that the surface of the PMIMPbBr3 single crystal film is smooth, transparent, and uniform.

[0037] Example 2 The preparation method of perovskite single crystal film PMIMPbI3 provided by this invention includes the following specific steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.922 g) of lead iodide (PbI2), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution 1: Weigh 3 mmol (0.6153 g) of 1-propyl-3-methylimidazolium bromide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 3 mmol / mL; (3) Preparation of halogenated imidazole precursor solution 2: Weigh 2 mmol (0.588 g) of 1-hexyl-3-methylimidazolium iodide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of PMIMPbI3 single crystal film: The metal halide precursor, halogenated imidazole precursor 1, and halogenated imidazole precursor 2 were mixed in a molar ratio of 1:0.6:0.4 and set aside. A clean FTO glass substrate (1.5cm × 1.5cm) was placed on a 120℃ hot plate. 125μL of the prepared solution was then pipetted onto the FTO glass substrate for in-situ growth. After growth, annealing was performed. After annealing for 30 minutes, a 2mL syringe needle was used to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). Crystals were observed to grow with a high degree of orientation along the diagonal direction from the nucleation point. Figure 1 As shown in Figure b, the general growth process can be observed. After surface growth, the sample is annealed for 20 hours, then cooled to room temperature at a programmed rate of 4.5℃ / h before being removed. The PMIMPbI3 single crystal film is now complete. Figure 2 As shown in Figure b, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10 μm to 300 μm.

[0038] It is worth noting that other growth substrates can also be used for the conductive substrate of PMIMPbI3 single crystal film. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs. Figure 8 A large-area PMIMPbI3 single-crystal film was grown in situ using 10cm×10cm FTO glass as the conductive substrate. XRD tests were performed on the film, and the results are as follows: Figure 9 As shown, it exhibits very strong overtone diffraction peaks; as measured by atomic force microscopy (AFM), such as... Figure 10 As shown, its surface smoothness is at the nanometer level.

[0039] Example 3 The preparation method of perovskite single crystal film PMIMSnI3 provided by the present invention includes the following specific steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.745 g) of stannous iodide (SnI2), then add 1 mL of ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.504 g) of 1-propyl-3-methylimidazolium iodide, then add 1 mL of ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of PMIMSnI3 single crystal film: The metal halide precursor and the halide imidazole precursor are mixed at a molar ratio of 1:1 and set aside. A clean FTO glass (1.5cm × 1.5cm) is placed on a hot stage at 120℃~140℃ for in-situ growth. After growth, annealing is performed. After annealing for 15 minutes, the glass is quickly transferred to a hot stage at approximately 60℃ or below. Then, a 2mL syringe needle is used to quickly stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be observed that the crystal grows with a high degree of orientation along the diagonal direction from the nucleation point. Figure 1 As shown in Figure c, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a programmed rate of 5.0℃ / h before being removed. The PMIMSnI3 single crystal film preparation is complete. Figure 2 As shown in c, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0040] XRD tests were performed on the PMIMSnI3 single crystal film, such as... Figure 11 As shown, it has a very strong overtone diffraction peak.

[0041] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0042] Example 4 The preparation method of perovskite single crystal film (EMIM) 3Bi2I9 provided by the present invention includes the following specific implementation steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 1 mmol (0.5897 g) of bismuth iodide (BiI3), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 1 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.476 g) of 1-ethyl-3-methylimidazolium iodide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of (EMIM)3Bi2I9 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 1:1.5 and set aside. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 120℃ hot stage, and then use a pipette to drop 125μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for 15 minutes, use the tip of a syringe to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows with a high degree of orientation along the diagonal direction from the point where the crystal nucleus is generated. Figure 1 As shown in Figure d, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a rate of 12℃ / h before being removed. The (EMIM)3Bi2I9 single crystal film is now complete. Figure 2 As shown in d, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted from 10μm to 300μm.

[0043] XRD tests were performed on the (EMIM)3Bi2I9 single crystal film, such as... Figure 12 As shown, it has a very strong overtone diffraction peak.

[0044] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0045] Example 5 The preparation method of the perovskite single crystal film (EMIM) 3Bi2Br3I6 provided by the present invention includes the following specific implementation steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 1 mmol (0.5897 g) of bismuth iodide (BiI3), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 1 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.382 g) of 1-ethyl-3-methylimidazolium bromide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of (EMIM)3Bi2Br3I6 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 1:1.5 and set aside. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 120℃ hot stage, and then use a pipette to drop 125μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for about 12 minutes, use the tip of a 2mL syringe needle to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows highly oriented diagonally from the nucleation point. Figure 1 As shown in Figure e, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a rate of 10℃ / h before being removed. The (EMIM)3Bi2Br3I6 single crystal film is thus prepared. Figure 2 As shown in Figure e, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0046] The (EMIM)3Bi2I9 single crystal film prepared in this embodiment was subjected to XRD testing, as shown below. Figure 13 As shown, it has a very strong overtone diffraction peak.

[0047] It is worth noting that the conductive substrate of the (EMIM)3Bi2Br3I6 single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0048] The (EMIM)3Bi2I9 single-crystal film prepared in this embodiment is integrated onto a TFT array circuit, such as... Figure 14 As shown in Figure a; then attach a Cu electrode, as shown in Figure a. Figure 14 As shown in b; then mounted on LinkZill's imaging system, such as Figure 15 As shown in Figure a; finally, it is moved to an X-ray source for imaging, as shown in Figure a. Figure 15 As shown in b; its image is displayed on the mobile app, and the effect is as follows. Figure 15 As shown in c.

[0049] Example 6 The preparation method of perovskite single crystal film (EMIM) 3Sb2Br9 provided by the present invention includes the following specific implementation steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.723 g) of antimony bromide (SbBr3), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) or ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.382 g) of 1-ethyl-3-methylimidazolium bromide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) or ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of (EMIM)3Sb2Br9 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 1:1.5 and set aside. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 120℃ hot stage, and then use a pipette to drop 125μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for 15 minutes, use the tip of a syringe to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows with a high degree of orientation along the diagonal direction from the point where the crystal nucleus is generated. Figure 1 As shown in Figure f, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a rate of 11.5℃ / h before being removed. The preparation is then complete. Figure 2 As shown in f, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0050] XRD tests were performed on the (EMIM)3Sb2Br9 single crystal film, and the results were as follows: Figure 16 As shown, it has a very strong overtone diffraction peak.

[0051] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0052] Example 7 The preparation method of perovskite single crystal film (EMIM) 3Sb2I9 provided by the present invention includes the following specific implementation steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (1.005 g) of antimony iodide (SbI3), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.476 g) of 1-ethyl-3-methylimidazolium iodide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of (EMIM)3Sb2I9 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 1:1.5 and set aside. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 125℃ hot stage, and then use a pipette to drop 125μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for 12 minutes, use the tip of a 2mL syringe to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows highly oriented diagonally from the nucleation point. Figure 1 As shown in Figure g, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a programmed rate of 12℃ / h before being removed. The preparation is then complete. Figure 2 As shown in g, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0053] XRD tests were performed on the (EMIM)3Sb2I9 single crystal film, such as... Figure 17 As shown, it has a very strong overtone diffraction peak.

[0054] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0055] Example 8 The preparation method of perovskite single crystal film (EMIM) 3In2I9 provided by the present invention includes the following specific implementation steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.991 g) of indium iodide (InI3), then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) or ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.476 g) of 1-ethyl-3-methylimidazolium iodide, then add 1 mL of ultra-dry dimethyl sulfoxide (DMSO) or ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of (EMIM)3In2I9 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 1:1.5 and set aside. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 70℃ hot stage, and then use a pipette to drop 70μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for 20 minutes, use the tip of a 2mL syringe to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). It can be seen that the crystal grows highly oriented diagonally from the nucleation point. Figure 1 As shown in Figure h, the general growth process can be observed. After surface growth, annealing for 6 hours is performed, followed by a programmed cooling rate of 8.5℃ / h to room temperature before the sample is removed. The (EMIM)3In2I9 single crystal film preparation is complete. Figure 2 As shown in h, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted within the range of 10μm to 300μm.

[0056] XRD tests were performed on the (EMIM)3In2I9 single crystal film, such as... Figure 18 As shown, it has a very strong overtone diffraction peak.

[0057] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0058] Example 9 The preparation method of perovskite single crystal film EMIMCu2BrI2 provided by the present invention includes the following specific steps: S1. Conductive substrate pretreatment: Using FTO glass as the conductive substrate, ultrasonically clean it for 20 minutes each with deionized water and anhydrous ethanol, dry it with nitrogen, and finally clean the surface with a plasma cleaner. S2、(1) Preparation of metal halide precursor solution: Weigh 2 mmol (0.381 g) of cuprous iodide (CuI), then add 1 mL of ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; (2) Preparation of halogenated imidazole precursor solution: Weigh 2 mmol (0.382 g) of 1-ethyl-3-methylimidazolium bromide, then add 1 mL of ultra-dry N,N-dimethylformamide (DMF) to dissolve it, and prepare a concentration of 2 mmol / mL; S3. Preparation of EMIMCu2BrI2 single crystal film: Mix the metal halide precursor solution and the halide imidazole precursor solution at a molar ratio of 2:1. Place the cleaned FTO glass (1.5cm × 1.5cm) on a 60℃ hot stage. Then, use a pipette to drop 70μL of the prepared solution onto the FTO glass substrate for in-situ growth. After the growth is complete, perform annealing. After annealing for 20 minutes, use the tip of a 2mL syringe to stimulate a corner of the FTO glass substrate surface (equivalent to manually "nucleating" the crystal). You can see that the crystal grows highly oriented diagonally from the nucleation point. Figure 1 As shown in Figure i, the general growth process can be observed. After surface growth, the sample is annealed for 6 hours, then cooled to room temperature at a programmed rate of 7.5℃ / h before being removed. The EMIMCu2BrI2 single crystal film is now complete. Figure 2 As shown in Figure i, the amount of material dropped onto conductive substrates of different sizes with varying thicknesses can be flexibly adjusted, and the film thickness can be adjusted from 10 μm to 300 μm.

[0059] It is worth noting that the conductive substrate of this single crystal film can also be other growth substrates. The area of ​​the conductive substrate can be designed from 1.5cm×1.5cm to 10cm×10cm, but is not limited to this size and can be adjusted according to actual needs.

[0060] The crystals of the large-area perovskite single crystal films prepared in Examples 1 to 9 were tested, and their parameters are shown in Table 1.

[0061] Table 1

[0062] As can be seen from the crystal system, space group, and cell parameters in Table 1, the thin films prepared in Examples 1 to 9 of this invention are all single-crystal materials.

[0063] Comparative Example 1 In Examples 1 to 3 and Examples 5, the manual "nucleation" operation was omitted during the preparation of the single-crystal films; that is, the step of stimulating a corner of the FTO glass substrate surface with the tip of a 2mL syringe needle was deleted. Other conditions and steps remained unchanged, and the resulting perovskite films were as follows. Figure 19As shown in Figures a, b, c, and d, the XRD patterns are as follows: Figure 20 As shown in Figures a, b, c, and d. Figure 19 and Figure 20 It can be seen that: without manually forming a polycrystalline film rather than a single-crystal film for the crystal nucleus, the XRD test shows that its diffraction peaks are disordered.

[0064] Example 10 This embodiment provides a method for fabricating an X-ray detector, the steps of which are as follows: using the large-area perovskite single crystal films obtained in Examples 1 to 3 and Example 5 as the perovskite layer, approximately 1 / 5 of the corresponding single crystal film is peeled off to expose the conductive layer of the underlying conductive substrate 1; then, it is placed in a vacuum coating machine at 2×10⁻⁶ ℃. -4 Under Pa pressure, electrodes 2 (gold electrodes in this embodiment) are thermally deposited on the upper surface of the single crystal film and the exposed portion of the conductive substrate 1 through a mask. The thickness of electrode 2 is 100 nm, thus obtaining the X-ray detector. The X-ray detectors corresponding to the large-area perovskite single crystal films in Examples 1 to 3 and Example 5 are denoted as X-I, X-II, X-III, and X-IV, respectively. Figure 21 As shown, the X-ray detector comprises a conductive substrate 1, a perovskite layer 2, and an electrode 3 stacked sequentially from bottom to top.

[0065] The current density-time curves of the X-ray detectors (X-I, X-II, X-III, and X-IV) under different bias voltages are shown below. Figures 22 to 25 As shown, the current density-time plots at different bias voltages and different dose rates correspond to... Figure 26 a, b, c, and d.

[0066] Dark current drift tests were performed on X-ray detectors (X-I, X-II, X-III, and X-IV), and the results are as follows: Figure 25 As shown in Figures a, b, c, and d. Among them, Figure 27 Figure 'a' indicates that the long-term dark current drift level of the X-I X-ray detector in dark conditions is 5.18 × 10⁻⁶. -9 nA cm -1 V -1 s -1 ; Figure 27 Figure b indicates that the long-term dark current drift level of the X-II X-ray detector in dark conditions is 7.6 × 10⁻⁶. -9 nA cm -1 V -1 s -1 ; Figure 27 The value of c indicates that the long-term dark current drift level of the X-ray detector X-III in dark conditions is 6.7 × 10⁻⁶. -9 nA cm -1 V -1 s -1 , Figure 27 The value of d indicates that the long-term dark current drift level of the X-IV X-ray detector in dark conditions is 1.98 × 10⁻⁶. -8 nA cm -1 V -1 s -1 Therefore, it can be seen that the X-ray detectors X-I, X-II, X-III and X-IV of the present invention have excellent dark current drift stability during long-term use.

[0067] In addition, the stability of the X-ray detector X-I under optical conditions was tested, such as... Figure 28 As shown, at 2.05 mGy air s -1 After prolonged dose-rate irradiation followed by dark current drift testing, the dark current drift level of this X-ray detector was found to be 2.7 × 10⁻⁶. -10 nA cm -1 V -1 s -1 This demonstrates that the X-ray detector of the present invention exhibits excellent operational stability even under high radiation doses and prolonged operation.

[0068] Comparative Example 2 This comparative example is a commercially available direct-type X-ray detector based on monocrystalline silicon, manufactured by Amptek Inc. of the United States, model XR-100SDD.

[0069] Comparative Example 3 This comparative example is a commercially available direct-type X-ray detector based on amorphous selenium. The detector is manufactured by KA Imaging, Canada, and its model is BrillianSe. TM .

[0070] Comparative Example 4 This comparative example is a commercially available direct-type X-ray detector based on zinc cadmium telluride. The detector is manufactured by Shaanxi Ditech New Materials Co., Ltd., and its model number is DT-P01.

[0071] The test parameters of the X-ray detector prepared in Example 10 above and the commercial X-ray detectors of Comparative Examples 2 to 4 were compared, and the results are shown in Table 2.

[0072] Table 2

[0073] The sensitivities in Table 2 above were calculated with a bias voltage of 1V. As can be seen from the data in Table 1, the X-ray detectors prepared in the embodiments of the present invention have higher sensitivities than the commercial high-performance X-ray detectors of Comparative Examples 2 to 4.

[0074] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing large-area perovskite single crystal films, characterized in that, The preparation method includes the following steps: The conductive substrate undergoes surface cleaning treatment; Metal halides and halogenated imidazoles are dissolved in organic solvents to prepare metal halide precursor solutions and halogenated imidazole precursor solutions, and then mixed in a predetermined ratio to obtain perovskite precursor solutions. The conductive substrate is placed on a hot stage for preheating. The perovskite precursor solution is drop-coated onto the conductive substrate for in-situ growth. Then, annealing is performed. After annealing for a period of time, crystal nucleation control is performed. After annealing, the temperature is cooled to room temperature through a program to obtain a large-area perovskite single crystal film. The general structural formula for large-area perovskite single-crystal film materials is: A m B n X z In the formula, A is an imidazole positive ion, m is its atomic number, m=1~3; B is a metal cation, n is its atomic number, n=1~2; X is a halide anion, z is its atomic number, z=3~9; The general structural formula for A is: or R is an alkyl or alkylamine group; The step of nucleus control is as follows: using a sharp object to stimulate any corner of the upper surface of the conductive substrate, causing it to nucleate at the corner and grow in a highly oriented manner along the diagonal direction.

2. The method for preparing a large-area perovskite single crystal film according to claim 1, characterized in that, The A m B n X z If the cation is ABX3, then B is a divalent metal cation, and B is selected from Pb. 2+ Sn 2+ 、Ge 2+ Zn 2+ Cd 2+ or Cu 2+ Furthermore, the molar ratio of the metal halide to the halogenated imidazole is 1:0.9~1.

2.

3. The method for preparing a large-area perovskite single crystal film according to claim 1, characterized in that, The A m B n X z If the cation is A3B2X9, then B is a trivalent metal cation, and B is selected from Sb. 3+ Bi 3+ In 3+ Eu 3+ or Tb 3+ Furthermore, the molar ratio of the metal halide to the halogenated imidazole is 1:1.3~1.

7.

4. The method for preparing a large-area perovskite single crystal film according to claim 1, characterized in that, The A m B n X z If the cation is AB2X3, then B is a monovalent metal cation, and B is selected from Cu. + Ag + or In + Furthermore, the molar ratio of the metal halide to the halogenated imidazole is 2:0.8~1.

2.

5. The method for preparing a large-area perovskite single crystal film according to any one of claims 1 to 4, characterized in that, A is selected from any one of equations (1) to (5): 。 6. The method for preparing a large-area perovskite single crystal film according to claim 1, characterized in that, The temperature of the heating plate is 60℃~150℃, the annealing time is 6h~48h, and the cooling rate is 1.5℃ / h~17.0℃ / h.

7. The method for preparing a large-area perovskite single crystal film according to claim 1, characterized in that, The organic solvent is selected from at least one of amide solvents, sulfoxide solvents, sulfone solvents, ester solvents, hydrazide solvents, nitrile solvents, alcohol solvents, ketone solvents, pyridine, and tetrahydrofuran.

8. The large-area perovskite single crystal film prepared by the method according to any one of claims 1 to 7.

9. The application of the large-area perovskite single crystal film according to claim 8, characterized in that, The large-area perovskite single crystal film is used to fabricate optoelectronic devices.

10. An X-ray detector, characterized in that, The X-ray detector comprises a conductive substrate, a perovskite layer, and electrodes stacked sequentially from bottom to top; the perovskite layer is a large-area perovskite single-crystal film as described in claim 8. The steps for fabricating an X-ray detector are as follows: peel off 1 / 8 to 1 / 4 of a large-area perovskite single crystal film to expose the conductive layer of the conductive substrate, and then deposit an electrode with a thickness of 100 nm to 150 nm on the surface of the large-area perovskite single crystal film and the exposed conductive substrate to obtain the X-ray detector.

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