Perovskite crystal, preparation method thereof and X-ray detector

Abstract

The present invention discloses a perovskite crystal, a preparation method thereof and an X-ray detector. The present invention provides a perovskite crystal; wherein the perovskite crystal comprises: a perovskite single crystal and a passivation layer; wherein the passivation layer is formed by the surface defects of the perovskite single crystal and the A 1 X 1 Combining the structure formed; and the perovskite crystal does not contain A that is not combined with the surface defects of the perovskite single crystal 1 X 1 The present invention performs a passivation modification treatment on the surface of the perovskite crystal. The passivation modification treatment increases the ion activation energy of the perovskite crystal, improves the ion mobility phenomenon, and reduces the dark current of the device; at the same time, a high-efficiency X-ray radiation detector with a coplanar structure of a perovskite single crystal is prepared; it has high sensitivity and a low detection limit, and realizes fine X-ray imaging and line array imaging.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite radiation detectors, and in particular relates to a perovskite crystal, a preparation method thereof, and an X-ray detector. Background Art

[0002] High-performance X-ray detectors have important applications in many fields, such as medical imaging, security monitoring, material analysis, and scientific experiments. Medical imaging, in particular, has been widely used. However, high doses of X-rays can cause irreversible damage to the human body, requiring X-ray detectors with high sensitivity to enable imaging at lower doses. Amorphous selenium has been the most widely used direct-conversion X-ray detector in recent decades. However, detectors based on this material suffer from low sensitivity, making accurate imaging at low radiation doses impossible. This is primarily due to its low atomic number and small carrier migration lifetime product.

[0003] Over the past decade or so, organic and inorganic halogen perovskites have developed rapidly, particularly in solar cells, light-emitting diodes, and photodetectors. Perovskite materials have also been demonstrated as a novel X-ray radiation detector. Compared to traditional silicon- and selenium-based X-ray radiation detectors, perovskite materials possess higher atomic numbers, lower trap densities, and larger carrier migration lifetime products. Furthermore, perovskite materials are inexpensive to prepare. These properties provide a reliable foundation for achieving high-sensitivity, low-dose imaging.

[0004] The current best X-ray detector based on perovskite materials has a minimum detection limit of 0.62nGy air s -1 Currently, all perovskite-based X-ray detectors have a sandwich structure, and there are few reports of perovskite X-ray detectors with a coplanar structure. The main advantage of this coplanar structure is that it separates the photosensitivity process from the charge transfer process, making the collection efficiency independent of the thickness of the active layer. However, perovskite materials are ionic crystals, and ion migration is prone to occur when an external electric field is applied. Ion migration can cause dark current drift in the device, making it difficult to read the signal. It can also produce traps and even material decomposition, reducing device efficiency. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the shortcomings of perovskite in the prior art by providing a perovskite crystal, a preparation method thereof, and an X-ray detector. This invention performs a passivation modification treatment on the surface of a perovskite single crystal. This passivation modification treatment increases the ion activation energy of the single crystal, improves ion mobility, and reduces the device dark current. Furthermore, a high-efficiency X-ray radiation detector with a coplanar structure of the perovskite single crystal is produced. This X-ray radiation detector currently achieves the lowest detection limit in the field and enables precise X-ray imaging and linear array imaging.

[0006] The present invention solves the above technical problems through the following technical solutions.

[0007] The present invention provides a perovskite crystal, wherein the perovskite crystal comprises: a perovskite single crystal and a passivation layer;

[0008] Wherein, the passivation layer is formed by the surface defects of the perovskite single crystal and the 1 X 1 the structure formed by the combination;

[0009] and the perovskite crystal does not contain (excess) A that is not bound to the surface defects of the perovskite single crystal. 1 X 1 (i.e., doped layer);

[0010] The A 1 Ammonium cation NH4 + , methylamine cation CH3NH3 + 、Formamidinium cation HC(NH2)2 + , cesium ion Cs + 、Rubidium ion Rb + 、Dimethylamine cation (CH3)2N + , ethylamine cation CH3CH2NH3 + 、Propylamine cation CH3(CH2)2NH3 + 、Butylamine cation CH3(CH2)3NH3 + 、Hexamethylenediamine cation NH3(CH2)6NH3 2+ , phenylethylamine cation and adamantaneamine cation C 10 H 18 N + One or more of;

[0011] The X 1 It is one or more of halide ion, thiocyanate ion and sulfate ion.

[0012] In one embodiment, the perovskite crystal comprises: a perovskite single crystal and a passivation layer;

[0013] Wherein, the passivation layer is formed by the surface defects of the perovskite single crystal and the 1 X 1 the structure formed by the combination;

[0014] and the perovskite crystal does not contain (excess) A that is not bound to the surface defects of the perovskite single crystal. 1 X 1 (i.e., doped layer);

[0015] The A 1 Ammonium cation NH4 + , methylamine cation CH3NH3 + 、Formamidinium cation HC(NH2)2 + , cesium ion Cs + 、Rubidium ion Rb + 、Dimethylamine cation (CH3)2N + , ethylamine cation CH3CH2NH3 + 、Propylamine cation CH3(CH2)2NH3 + 、Butylamine cation CH3(CH2)3NH3 + 、Hexamethylenediamine cation NH3(CH2)6NH3 2+ and adamantane amine cation C 10 H 18 N + One or more of;

[0016] The X 1 It is one or more of halide ion, thiocyanate ion and sulfate ion.

[0017] Conventional perovskite single crystals in this field generally have defects on their surfaces. The reasons for this are: surface defects caused by the physical processing, cutting, shaping, and surface treatment of the perovskite material. Furthermore, when the perovskite single crystal is removed from the mother liquor after growth, temperature changes and solution disturbances can cause the crystal surface to be redissolved and precipitated. When the surface material dissolves at different rates, vacancy defects are easily formed. For example, when the perovskite single crystal is CH3NH3PbI3, whether grown using a ramping or cooling method, the solubility and dissolution rate of methyl iodide and lead iodide on the surface of the perovskite single crystal vary greatly with temperature. Methyl iodide dissolves more and faster, resulting in methyl iodide missing on the single crystal surface, forming methyl amine vacancies and unbonded halogens or lead.

[0018] In the present invention, the passivation generally refers to eliminating surface defects of the perovskite single crystal.

[0019] In the present invention, the passivation layer generally refers to a structure formed after eliminating surface defects of the perovskite single crystal.

[0020] Specifically, the passivation layer is formed by A 1 X 1 The surface defects of the perovskite single crystal are 1 X 1 Combined, the structure is formed after the surface defects of the perovskite single crystal are eliminated.

[0021] In the present invention, the surface of the perovskite crystal does not contain a doping layer; the doping layer refers to the surface of the perovskite single crystal modified by the surface passivation, and there is an A 1 X 1 Layer (which consists of excess A 1 X 1 structure formed by interaction with the passivation layer).

[0022] In the present invention, compared with conventional perovskite single crystals in the field, the defects on the surface of the single crystal disappear after passivation modification; and after passivation modification, the density of the single crystal surface is greatly reduced, the ion activation energy is improved, and the dark current of the prepared device is stable and does not drift.

[0023] In the present invention, the thickness of the passivation layer may be 0.1-3 nm.

[0024] In the present invention, the A 1 Preferably, the ammonium cation NH4 + , methylamine cation CH3NH3 + 、Formamidinium cation HC(NH2)2 + , cesium ion Cs + and rubidium ions Rb + One or more of, more preferably methylamine cation CH3NH3 + .

[0025] In the present invention, X 1 In the embodiment, the halide ion may be a fluoride ion F - , iodide ion I - 、Br - or chloride ion Cl - Preferably, the X 1 Iodide ion I - 、Br - 、Chloride ion Cl - , thiocyanate ion or sulfate ion, such as iodide ion I - .

[0026] In the present invention, the A 1 X 1 Preferred is CH3NH3I.

[0027] In the present invention, the perovskite single crystal can be a three-dimensional perovskite, a two-dimensional perovskite, a two-dimensional three-dimensional mixed perovskite, a zero-dimensional perovskite, or a double perovskite. The molecular formula of the three-dimensional perovskite is ABX3. The molecular formula of the two-dimensional perovskite and the two-dimensional three-dimensional mixed perovskite is M2A n-1 B n X 3n+1 , the zero-dimensional perovskite molecular formula may be A3C2X9, and the double perovskite molecular formula may be A2CDX6.

[0028] Wherein, the A is preferably ammonium cation, methylamine cation CH3NH3 + 、Formamidinium cation HC(NH2)2 + 、Dimethylamine cation (CH3)2N + , cesium ion Cs + and rubidium ions Rb + One or more of, for example, methylamine cation CH3NH3 + .

[0029] Wherein, the B is preferably lead ion Pb 2+ , tin ions Sn 2+ and germanium ions Ge 2+ One or more of, for example, lead ion Pb 2+ .

[0030] Wherein, the C is preferably a bismuth trivalent cation Bi 3+ , antimony trivalent cation Sb 3+ 、Aluminum trivalent cation Al 3+ 、Indium trivalent cation In 3+ , gallium trivalent cation Ga 3+ One or more of, for example, bismuth trivalent cation Bi 3+ .

[0031] Wherein, the D is preferably a silver monovalent cation Ag + 、Lithium monovalent cation Li + , sodium monovalent cation Na + 、Potassium monovalent cation K + 、Rubidium monovalent cation Rb + One or more of, for example, silver monovalent cation Ag + .

[0032] Wherein, the X is preferably an iodide ion I - 、Br - and chloride ions Cl - One or more of, for example, iodide ion I - .

[0033] Wherein, the M is preferably a phenylethylamine cation C6H5CH2CH2NH3 + , ethylamine cation CH3CH2NH3 + 、Propylamine cation CH3(CH2)2NH3 + 、Butylamine cation CH3(CH2)3NH3 + 、Hexamethylenediamine cation NH3(CH2)6NH3 2+ and adamantane amine cation C 10 H 18 N + One or more of .

[0034] Wherein, n is generally a positive integer (such as 1, 2, 3, 4, ..., ∞). When n=1, it is a two-dimensional perovskite, and the rest are two-dimensional and three-dimensional mixtures.

[0035] In the present invention, the molecular formula of the perovskite single crystal is preferably CH3NH3PbI3.

[0036] In the present invention, when the perovskite single crystal is CH3NH3PbI3, the A 1 X 1 Preferred is CH3NH3I.

[0037] The present invention also provides a method for preparing a perovskite single crystal, which comprises the following steps: 1 X 1 The solution is coated on the surface of the perovskite single crystal to form a passivation layer; the A 1 X 1 A is not too much or too much (i.e., it does not form a passivation layer with the surface defects of the perovskite single crystal). 1 X 1 );

[0038] When the A 1 X 1 When the amount is excessive, it also includes removing the excess A 1 X 1 That's it;

[0039] The A 1 X 1 As mentioned above.

[0040] The perovskite single crystal has surface defects, wherein the explanation of the surface defects of the perovskite single crystal is as described above.

[0041] Wherein, the molecular formula and preparation method of the perovskite single crystal are as described above.

[0042] Wherein, the 1 X 1 In the solution, the A1 X 1 The concentration can be <20 mg·mL -1 ; preferably 0.5-5mg·mL -1 , more preferably 0.5-2 mg·mL -1 , for example 1 mg·mL -1 .

[0043] Wherein, the 1 X 1 The solvent of the solution may be one or more of isopropyl alcohol, methanol, sec-butyl alcohol, toluene, chlorobenzene, and dichloromethane. The coating method may be spin coating. The spin coating speed may be 1000-5000 rpm, for example, 3000 rpm. The spin coating time may be 5-60 s, for example, 30 s.

[0044] Wherein, the excess A (outside the passivation layer) is removed 1 X 1 The operation may be coating solvent. The coating method may be spin coating. The spin coating speed may be 1000-5000 rpm, for example 3000 rpm. The spin coating time may be 5-60 s, for example 30 s. The coating solvent may be the A 1 X 1 The solvent used for the solution may be one or more of isopropanol, methanol, sec-butanol, toluene, chlorobenzene and dichloromethane, such as isopropanol.

[0045] In the present invention, the method may further include post-processing, which may be annealing according to conventional operations in the art. The temperature of the annealing treatment may be 40-200°C, for example, 50°C. The time of the annealing treatment may be 1s-30min. For example, 1 X 1 The solution is coated on the surface of the perovskite single crystal and then annealed for 2 minutes; or, after the passivation layer is formed, it also contains excess A (which does not form a passivation layer with the surface defects of the perovskite single crystal) 1 X 1 When the excess A outside the passivation layer is removed 1 X 1 Post-annealing treatment for 10 min.

[0046] In the present invention, the perovskite single crystal can be prepared by conventional methods in the field, such as high-temperature sintering, vapor deposition, anti-solvent, solution heating and solution cooling; preferably, it can be prepared by spatial confined temperature crystallization (which belongs to the temperature rising method and is a further extension of the temperature rising method); it can also be obtained by one-time direct growth and cutting and polishing to obtain a single crystal thin sheet.

[0047] The spatially confined temperature crystallization method may comprise the following steps: heat-treating a structure comprising, in sequence, a second hydrophobic substrate layer, a perovskite precursor solution layer, and a first hydrophobic substrate layer to obtain the perovskite single crystal. The structure may be produced by dripping a perovskite precursor solution onto a first hydrophobic substrate and then covering the perovskite precursor solution with a second hydrophobic substrate.

[0048] The perovskite precursor solution can be prepared by conventional methods in the art, for example, by mixing a solute capable of generating a perovskite precursor with a solvent and stirring. The stirring temperature can be 25-100° C., for example, 70° C., and the stirring time can be 1-24 hours, for example, 2 hours.

[0049] The solutes that can generate the perovskite precursor may include "AX and BX2" or "AX, MX and BX2" or "AX, CX3" or "AX, CX3 and DX".

[0050] The definition of A is as described above.

[0051] The definition of B is as described above.

[0052] The definition of C is as described above.

[0053] The definition of D is as described above.

[0054] The definition of X is as described above.

[0055] The definition of M is as described above.

[0056] When the solute capable of generating a perovskite precursor includes "AX and BX2", the molar ratio of AX and BX2 can be determined according to the molecular formula of the perovskite single crystal, for example, 1:1.

[0057] When the solute capable of generating a perovskite precursor includes "AX, MX, and BX2", the molar ratio of AX, MX, and BX2 can be determined according to the molecular formula of the perovskite single crystal, for example, 2:1:1.

[0058] When the solute capable of generating a perovskite precursor includes "AX, CX3", the molar ratio of AX to CX3 can be determined according to the molecular formula of the perovskite single crystal, for example, 3:2.

[0059] When the solute capable of generating a perovskite precursor includes "AX, CX3, and DX", the molar ratio of AX, CX3, and DX can be determined according to the molecular formula of the perovskite single crystal, for example, 2:1:1.

[0060] In the perovskite precursor solution, the concentration of the perovskite precursor can be 1-2.5 mol·L-1 , for example 1.5 mol·L -1 .

[0061] The solvent in the perovskite precursor solution may be a conventional solvent in the art, such as one or more of N,N-dimethylformamide, γ-butyrolactone and dimethyl sulfoxide, and another example is γ-butyrolactone.

[0062] The first hydrophobic substrate and the second hydrophobic substrate can be conventional hydrophobic substrates in the art that can be used to prepare the perovskite single crystal, such as a glass substrate coated with a hydrophobic agent. The hydrophobic agent can be one or more of 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane, 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane, poly [bis (4-phenyl) (2, 4, 6-trimethylphenyl) amine], trifluoropropyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropylmethyldimethoxysilane, per(heptadecafluorodecyltrimethoxysilane), per(heptadecafluorodecyltriethoxysilane, per(tridecafluorooctyltrimethoxysilane) and per(tridecafluorooctyltriethoxysilane), such as 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane.

[0063] The use of a hydrophobic substrate is beneficial to the microflow of the perovskite precursor solution during the growth of perovskite single crystals.

[0064] Preferably, before the perovskite precursor solution is dropped onto the first hydrophobic substrate, the first hydrophobic substrate is preheated at a temperature of 25-100°C, for example, 75°C.

[0065] In the spatially confined temperature rising crystallization method, the temperature of the heat treatment is preferably 50-150°C, for example 120°C.

[0066] In the spatially confined temperature rising crystallization method, the heat treatment time is preferably 1-100 hours, for example 10 hours.

[0067] The present invention also provides a surface-passivated perovskite single crystal, which is obtained by the above-mentioned preparation method of the perovskite single crystal. For example, the parameters of the surface-passivated perovskite single crystal are the same as those of the above-mentioned perovskite crystal.

[0068] The present invention also provides a use of the above-mentioned perovskite crystal or the above-mentioned surface-passivated modified perovskite single crystal as an active layer in a radiation detector;

[0069] The radiation detector may be a coplanar structure radiation detector (the coplanar structure is that the two electrode layers of the detector are on the same side of the active layer).

[0070] The present invention also provides an X-ray radiation detector comprising an active layer and an interdigitated electrode layer formed by a positive electrode layer and a negative electrode layer, wherein:

[0071] The active layer is the perovskite crystal as described above or the perovskite single crystal with surface passivation modification as described above.

[0072] The radiation detector may be a coplanar structure radiation detector (the coplanar structure means that the two electrodes of the detector are on the same side of the active layer).

[0073] The interdigitated electrode layer is a conventional interdigitated electrode layer in the art, for example, the positive electrode layer and the negative electrode layer are on the same side of the active layer, and the positive electrode layer and the negative electrode layer are not in direct contact.

[0074] In the present invention, the electrode layer may include a conductive layer and an interface layer, or only a conductive layer.

[0075] In the present invention, the conductive layer material of the interdigitated electrode layer can be a conventional electrode material in the art, such as carbon or metal, such as Cu, Au, Ag, Ga, In, Al, Pt, Ti, Bi or Cr; or a multilayer metal structure thereof.

[0076] In the present invention, the interface layer material of the interdigitated electrode layer can be a conventional material in the art with interface modification or energy level adjustment, such as C60, C70, BCP, PCBM, copper phthalocyanine, cuprous thiocyanate, NPB (N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine), TCTA (tris(4-carbazol-9-ylphenyl)amine), MCP (9,9'-(1,3-phenyl)di-9H-carbazole), TAPC (4-[1-[4-[di(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4 -methylphenyl)aniline), F4-TCNQ (2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone), PS (polystyrene), PMMA (polymethyl methacrylate), 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-β-(aminoethyl)γ-aminopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, cysteine, taurine, L-penicillamine, TiOX, MoOX, V2O5, WO3, LiF or Ca, etc., which have interface modification or energy level adjustment; or multilayer structures thereof. In a certain embodiment, the interface layer material of the interdigitated electrode layer is, for example, C60, C70, BCP, PCBM, copper phthalocyanine, cuprous thiocyanate, NPB (N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine), TCTA (tris(4-carbazol-9-ylphenyl)amine), MCP (9,9'-(1,3-phenyl)di-9H-carbazole), TAPC (4-[1-[4-[di( materials with interface modification or energy level adjustment such as TiOX, MoOX, V2O5, WO3, LiF or Ca; or multilayer structures thereof.

[0077] The two interface layers of the interdigitated electrode layer (in the positive electrode layer and the negative electrode layer) are made of the same or different materials or a combination thereof.

[0078] In the present invention, the thickness of the interface layer of the interdigitated electrode layer may be 1 nm-100 nm, for example, 20 nm.

[0079] In the present invention, the thickness of the conductive layer of the interdigitated electrode layer may be a conventional thickness in the art, such as 10 nm to 150 μm, and another example is 50 nm.

[0080] In the present invention, when the X-ray radiation detector is a coplanar single crystal perovskite X-ray radiation detector, its sensitivity can reach The minimum detection limit can reach 0.1nGy air s -1 ; It is the highest sensitivity and lowest detection limit of current X-ray radiation detectors.

[0081] The present invention also provides a method for preparing the X-ray radiation detector, which comprises the following steps:

[0082] (1) Covering the active layer with a mask, depositing or printing interface and conductive materials, and removing the mask; the active layer is a perovskite single crystal;

[0083] (2) The active layer is passivated and modified using the above-mentioned method for preparing the perovskite single crystal.

[0084] In step (1), the mask may be an interdigitated mask.

[0085] In step (1), the deposition rate of the material of the interdigitated electrode layer can be

[0086] In step (1), the deposition can be performed in a vacuum coating machine.

[0087] In step (1), the deposition method may be a conventional deposition method in the art, such as vacuum thermal evaporation deposition, thermal evaporation, magnetron sputtering or spraying.

[0088] In step (1), the printing method can be a conventional printing method in the art, such as screen printing.

[0089] In a certain embodiment, the parameters of the X-ray radiation detector are the same as those of the X-ray radiation detector described above.

[0090] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention.

[0091] The reagents and raw materials used in the present invention are commercially available.

[0092] The positive progress effect of the present invention is:

[0093] The present invention achieves controllable passivation and doping of the perovskite crystal surface through a very simple method, realizes the passivation of surface defects of the single crystal, improves the ion mobility effect, and successfully prepares a coplanar structure single crystal perovskite X-ray radiation detector, obtaining an excellent detector with high sensitivity and low detection limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1Schematic diagram of the device structure of Example 1.

[0095] Figure 2 This is a photo of the perovskite single crystal grown in Example 1.

[0096] Figure 3 This is a physical picture of the radiation detector device in Example 1.

[0097] Figure 4 The graphs are voltage-current curves of the devices in Example 1, Comparative Example 1, and Comparative Example 2 in the dark state.

[0098] Figure 5 1 is a current-time curve diagram of the device in the dark state in Example 1, Comparative Example 1, and Comparative Example 2.

[0099] Figure 6 This is a linear fitting diagram of current and voltage in the dark state of the perovskite single crystal surface defect concentration test device in Example 1, Comparative Example 1, and Comparative Example 2.

[0100] Figure 7 Graphs showing the ion activation energy test of perovskite single crystals in Example 1, Comparative Example 1, and Comparative Example 2.

[0101] Figure 8 These are steady-state spectra of the photoluminescence on the surface of the perovskite single crystal in Example 1, Comparative Example 1, and Comparative Example 2.

[0102] Figure 9 These are the photoluminescence transient spectra of the perovskite single crystal surface in Example 1, Comparative Example 1, and Comparative Example 2.

[0103] Figure 10 This is a diagram showing the changes in lead elements on the surface of the perovskite single crystal in Example 1, Comparative Example 1, and Comparative Example 2.

[0104] Figure 11 This is a graph showing the changes in carbon elements on the surface of the perovskite single crystal in Example 1, Comparative Example 1, and Comparative Example 2.

[0105] Figure 12 This is a curve diagram of the sensitivity of the perovskite single crystal device to X-ray radiation under different electric fields in Comparative Example 2.

[0106] Figure 13 This is the X-ray cycle recovery curve of the perovskite single crystal device in Comparative Example 2.

[0107] Figure 14 This is a curve chart of the X-ray radiation detection limit test of the perovskite single crystal device in Comparative Example 2.

[0108] Figure 15 This is a storage stability experimental curve diagram of the perovskite single crystal device in Comparative Example 2.

[0109] Figure 16 Graph showing noise test of the perovskite single crystal device in Example 1 and Comparative Example 2.

[0110] Figure 17 These are the photocurrent and dark current curves of the methylbutamine lead iodide-based two-dimensional and three-dimensional mixed perovskite single crystal device in Example 2.

[0111] Figure 18 This is the dark current stability curve of the methylbutamine lead iodide-based two-dimensional and three-dimensional mixed perovskite single crystal device in Example 2.

[0112] Figure 19 This is the X-ray step curve of the methylbutamine lead iodide-based two-dimensional and three-dimensional mixed perovskite single crystal device in Example 2.

[0113] Figure 20 The valence state change of gold element in different interface layer devices in Example 3.

[0114] Figure 21 These are the dark current output stability curves of the devices with and without the interface layer in Example 3.

[0115] Figure 22 Schematic diagram of a single pixel device in Example 3.

[0116] Figure 23 This is a photo of the line array device in Example 3.

[0117] Figure 24 This is the imaging result of the single-pixel device in Example 3.

[0118] Figure 25 This is the imaging result diagram of the linear array device in Example 3. DETAILED DESCRIPTION

[0119] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0120] Example 1

[0121] This example uses methylamino lead iodide perovskite single crystal as an example to prepare a coplanar structure single crystal perovskite X-ray radiation detector. Figure 1 This is a schematic diagram of the structure of a coplanar single crystal perovskite X-ray radiation detector. Figure 3 This is a physical picture of the radiation detector device. The specific steps are:

[0122] 1. Weigh equal amounts of CH3NH3I and PbI2, add γ-butyrolactone solvent, and prepare 1.5 mol·L -1The precursor solution was stirred at 70℃ for 2h, and the hydrophobic glass substrate was preheated on a 75℃ hot plate. The precursor solution was quickly dropped on the hydrophobic glass substrate (the hydrophobic reagent coated was 1H,1H,2H,2H-perfluorooctyltrichlorosilane), and another hydrophobic glass substrate was covered on it. The hot plate temperature was gradually raised to 120℃ and grown for 10h to obtain the following Figure 2 The single crystal shown.

[0123] 2. Fix the crystal on a glass sheet, cover it with the required interdigital electrode structure mask, and deposit 50nm of gold by vacuum thermal evaporation (deposition rate is ), remove the mask.

[0124] 3. Device doping: Spin-coat 1 mg mL on the device surface -1 The CH3NH3I IPA (isopropyl alcohol) solution was spin-coated at 3000 rpm for 30 s and annealed on a hot stage at 50°C for 2 min.

[0125] 4. Device passivation treatment: Spin-coat IPA on the device in step 3 again at 3000 rpm for 30 seconds, and anneal on a hot plate at 50°C for 10 minutes.

[0126] Comparative Example 1

[0127] The device obtained in step 2 of Example 1 is not subjected to any further treatment, and is referred to as the device of Comparative Example 1.

[0128] Comparative Example 2

[0129] The device obtained in step 3 of Example 1 is not further processed, and is the device of Comparative Example 2.

[0130] Example 2

[0131] This example takes the 2D and 3D mixed perovskite single crystal of methylaminobutylamino lead iodide as an example, and the crystal structure is (CH3(CH2)3NH3)2MA5Pb6I 19 Preparation of coplanar structure single crystal perovskite X-ray radiation detector, the schematic diagram of the coplanar structure single crystal perovskite X-ray radiation detector is the same as Figure 1 The specific steps are:

[0132] 1. According to the molecular ratio of CH3(CH2)3NH3I:MAI:PbI2=2:5:6, add γ-butyrolactone solvent to prepare 1.5mol·L -1The precursor solution was stirred at 70°C for 2 hours, and the hydrophobic glass substrate was preheated on a hot plate at 75°C; the precursor solution was quickly dropped on the hydrophobic glass substrate (the coated hydrophobic reagent was 1H,1H,2H,2H-perfluorooctyltrichlorosilane), and another hydrophobic glass substrate was covered on it; the hot plate temperature was gradually raised to 130°C, and the growth was carried out for 12 hours to obtain the desired single crystal.

[0133] 2. Fix the crystal on a glass sheet, cover it with the required interdigital electrode structure mask, and deposit 50nm of gold by vacuum thermal evaporation (deposition rate is ), remove the mask.

[0134] Example 3

[0135] This embodiment takes methylamino lead iodide perovskite single crystal as an example to prepare a coplanar structure single crystal perovskite X-ray radiation detector with an interface layer.

[0136] On the basis of Example 1, an interface layer is added between the single crystal passivation layer and the electrode layer to suppress the electrochemical reaction at the interface. The specific steps are:

[0137] 1. Crystal growth and passivation (same as Example 1).

[0138] 2. The interface layer C60 / BCP (20nm / 7nm) and MoO x (10 nm) were deposited under the cathode and anode electrodes respectively.

[0139] 3. Finally, a 50nm gold electrode (deposition rate of ) is deposited on the interface layer by thermal evaporation.

[0140] Effect Example 1

[0141] The single crystal device in Example 1 was taken as the surface passivation treatment with CH3NH3I; the single crystal device in Comparative Example 1 was taken as the untreated device; and the single crystal device in Comparative Example 2 was taken as the surface doping treatment with CH3NH3I.

[0142] (1) Dark current test of the device before and after CH3NH3I and IPA treatment on the device surface.

[0143] The single crystal device in Example 1, the single crystal device in Comparative Example 1, and the single crystal device in Comparative Example 2 were tested for device dark current.

[0144] The device was placed in a dark state, different voltages were applied to the device and the generated current was recorded. The voltage-current curves of the devices with different treatments in the dark state were obtained. The obtained curves are shown in Figure 4, some of the data are shown in Table 1. Similarly, the device is placed in a dark state, a constant voltage is applied to the device and the current changes over time are recorded to obtain the current-time curves of the devices with different treatments in the dark state. The obtained curves are shown in Figure 5 , some data are shown in Table 2. Figure 4 It can be seen that the device with surface CH3NH3I doping treatment obtains the highest dark state current, while the dark current of the device with CH3NH3I surface passivation treatment is much weaker. This shows that after the excessive CH3NH3I treatment, the single crystal surface forms a doping effect, which increases the lateral charge transfer capability of the single crystal surface; and after the device is treated with IPA, the excess CH3NH3I on the surface is cleaned away, and the CH3NH3I with passivation defects is retained, forming a passivation effect on the single crystal surface, thereby suppressing the dark current. Figure 5 It can be seen that the device after passivation treatment obtains a more stable constant voltage output, while the dark current drift in the other two cases is serious as time goes by.

[0145] Table 1

[0146]

[0147] Table 2

[0148]

[0149]

[0150] (2) Single crystal surface defect testing.

[0151] The space-charge-limited current (SCLC) of the untreated perovskite single crystal prepared in step 1 of Example 1 and the surface-treated perovskite single crystals of Comparative Examples 1 and 2 was compared. The specific detection method was as follows: a symmetrical layer of C60 (20 nm) / BCP (7.5 nm) / Au (50 nm) with a spacing of 50 μm was continuously thermally deposited on the surface of the untreated single crystal, and the current-voltage curve was measured in the dark. For the device doped with CH3NH3I, an excess amount of CH3NH3I was spin-coated on the surface of the untreated device, and the current-voltage curve was measured in the dark. For the device passivated with CH3NH3I, IPA was spin-coated on the CH3NH3I-doped device to remove excess CH3NH3I, and the current-voltage curve was measured in the dark.

[0152] Some of the data can be seen in Table 3 below.

[0153] Table 3

[0154]

[0155]

[0156]

[0157]

[0158] According to Table 3, Figure 6 It can be seen that the voltage V at which the current-voltage slope of the untreated perovskite single crystal changes TFL =3.61V, the voltage V at which the current-voltage slope of the perovskite single crystal changes after the CH3NH3I doping treatment TFL =1.26V, and after CH3NH3I treatment, the voltage V at which the current-voltage slope of the perovskite single crystal treated with IPA changes TFL =0.4V. Generally, the region after the transition point voltage is called the trap filling limit region. The lower the transition point voltage, the fewer surface defects the single crystal has. After calculation, the surface defects of the single crystal under the three treatment conditions are 1.63×10 10 cm -2 , 5.68×10 9 cm -2 and 1.8×10 9 cm -2 It can be seen that the surface defects of the perovskite single crystal passivated by CH3NH3I and IPA are significantly reduced.

[0159] (3) Automatic characterization of single crystal ions

[0160] The single crystal devices in Example 1, Comparative Example 1, and Comparative Example 2 were used to calculate the ion activation energy for each treatment method. The ion activation energy was calculated by measuring the temperature-dependent change in the single crystal's lateral conductivity under a constant electric field, and then calculating the ion activation energy using the Nernst-Einstein equation.

[0161] Specific data can be found in Table 4 below.

[0162] Table 4

[0163]

[0164] According to Table 4, Figure 7The transition point where the lateral conductivity of an untreated perovskite single crystal becomes dominated by ionic conductivity is 285 K, with an ionic activation energy of 0.984 eV. The transition point where the lateral conductivity of the perovskite single crystal becomes dominated by ionic conductivity after surface doping with CH3NH3I is 274 K, with an ionic activation energy of 0.814 eV. The transition point where the lateral conductivity of the perovskite single crystal becomes dominated by ionic conductivity after surface passivation with CH3NH3I is 295 K, with an ionic activation energy of 1.784 eV. Generally speaking, the electrical conductivity of a single crystal is primarily contributed by the movement of electrons and ions. At low temperatures, the contribution is primarily electronic, while at temperatures above the point where ions can move, the crystal conductivity is primarily contributed by ionic conductivity. Therefore, a higher temperature at this transition point means that ionic movement requires a higher temperature, making it less likely to occur. The conductivity contributed by ionic movement can be used to calculate the ionic activation energy. Similarly, a higher ionic activation energy indicates a lower likelihood of ionic movement.

[0165] (4) Single crystal photoluminescence spectrum detection

[0166] The single crystal treated in Example 1, the single crystal treated in Comparative Example 1, and the single crystal treated in Comparative Example 2 were taken to detect their luminescence spectra.

[0167] Figure 8 PL represents the change of the steady-state fluorescence spectrum of the crystal surface after different treatments of CH3NH3I. Figure 8 The results indicate a 3-nanometer blue shift in the surface fluorescence spectrum of the crystal after CH3NH3I doping, and a 5-nanometer blue shift after CH3NH3I passivation. This indicates that surface defects are reduced after CH3NH3I doping, and further reduced after CH3NH3I passivation. The primary reason for this is that while surface defects are passivated after CH3NH3I doping, the excess CH3NH3I on the crystal surface creates new surface defects. These defects disappear after the excess CH3NH3I is washed away with isopropyl alcohol.

[0168] Figure 9 TRPL represents the change of transient fluorescence spectrum of the crystal surface after different treatments of CH3NH3I. Figure 9 This shows that the crystal surface has a longer fluorescence lifetime after CH3NH3I passivation treatment compared with the other two treatments, indicating that the crystal surface recombination is reduced and the surface defects are fewer after CH3NH3I passivation treatment.

[0169] (5) Changes in elements on the single crystal surface

[0170] The single crystal in Example 1, the single crystal treated in Comparative Example 1, and the single crystal treated in Comparative Example 2 were taken and XPS (X-ray photoelectron spectroscopy) was used to detect changes in surface elements.

[0171] Figure 10 、 Figure 11 XPS, which shows the changes of Pb and C elements on the surface of the single crystal before and after different treatments. Figure 10 、 Figure 11 Note: There are metallic lead defects on the untreated crystal surface, but the metallic lead disappears after the doping treatment with excessive CH3NH3I. In addition, CH3NH3I is detected in the fitted carbon element after treatment with CH3NH3I, indicating that CH3NH3I forms a thin layer on the crystal surface. No excess CH3NH3I is detected on the crystal surface after passivation treatment with CH3NH3I, and no metallic lead is detected at the same time, indicating that after spin coating with IPA, the excess unbonded CH3NH3I is washed away without affecting the already bonded and passivated CH3NH3I.

[0172] Effect Example 2

[0173] (1) X-ray detection of coplanar perovskite single crystal devices

[0174] The single crystal device in Example 1 was placed in an X-ray source with an energy of up to 50 keV and a peak intensity of 22 keV to test its detection capability. Figure 12 The curve of device sensitivity changing with electric field strength. Figure 12 This shows that the detection sensitivity of this coplanar structure device has reached It is a detector with the highest sensitivity among current perovskite materials.

[0175] Figure 13 For devices at 20.3μGy air s -1 The recovery response under X-ray doses showed good recovery response ability.

[0176] Figure 14 The average sensitivity of the device is The relationship between different X-ray radiation doses and currents under different conditions was calculated, and the detection limit of the device was calculated to be as low as 1.5nGy. air s -1 , which is also the current lower detection limit of perovskite materials in X-ray radiation detection.

[0177] Figure 15 This is a stability test of the coplanar structure device. The specific data is shown in Table 5. The device was stored in a nitrogen atmosphere and tested in an air atmosphere. The specific data is shown in Table 5. The device can be maintained for about 700 hours and the sensitivity remains almost unchanged.

[0178] Table 5

[0179] Time (hours) <![CDATA[Sensitivity (microcoulomb per gray -1 centimeter -2 )]]> 0 862853.37768 48 753035.67507 96 784412.16153 264 768723.9183 312 862853.37768 432 815788.64799 528 878541.62091 672 909918.10737

[0180] The devices in Example 1 and Comparative Example 1 were tested for device noise. Figure 16 It can be seen that the device passivated with CH3NH3I exhibits low noise that is independent of frequency variation.

[0181] Effect Example 4

[0182] The device in Example 2 was taken and its basic properties were tested. Figure 17 For dark state current and light state current test, Figure 18 For the stability test in dark state, Figure 19 The step curve test under X-rays is shown in Tables 6, 7, and 8. It can be seen that the single crystal with this structure has low dark current and dark current stability, and has high X-ray detection performance.

[0183] Table 6

[0184]

[0185]

[0186]

[0187] Table 7

[0188]

[0189]

[0190] Table 8

[0191]

[0192]

[0193] Effect Example 5

[0194] The coplanar single crystal X-ray detector containing the interface layer prepared in Example 3 was used to test the inhibition of its interface electrochemical reaction.

[0195] Figure 20 The XPS spectra of Au elements at the interface with and without the interface layer in the working state are shown in Table 9. As can be seen from the figure, after a period of operation, the device without the interface layer has a peak of gold cations at the anode interface, which indicates that under the action of electricity, Au and the halogen in the perovskite have undergone electrochemical reactions.

[0196] Au(0)+2I - +h + →[AuI2] - +2V I

[0197] However, in the device with the interface layer added, no gold cations were found to be generated under the same working conditions, which proves that the addition of the interface layer can inhibit the electrochemical reaction at the interface.

[0198] Figure 21 Table 10 shows some of the dark current output data from devices with and without an interface layer. Suppressing the interfacial electrochemical reaction can suppress the initial rise in dark current. This suppression of the initial rapid current rise enables a rapid response to X-rays, enabling rapid, low-dose X-ray imaging.

[0199] Table 9

[0200]

[0201]

[0202] Table 10

[0203]

[0204]

[0205]

[0206]

[0207] Effect Example 6

[0208] The coplanar single crystal X-ray detector containing the interface layer prepared in Example 3 was used to test its imaging results under X-rays.

[0209] Figure 22 This is a schematic diagram of the structure of the single-pixel imaging test of the device in Example 3. Figure 23 This is a photo of the device line array imaging device in Example 3. Figure 24 The image below shows the imaging mask and the single-pixel imaging result. It can be seen that the device achieves high-quality imaging results. Figure 25 The imaging diagram and imaging results of the linear array device are shown. The device obtains clear imaging results of light and dark stripes.

Claims

1. A perovskite crystal, characterized in that: The perovskite crystal comprises: a perovskite single crystal and a passivation layer; Wherein, the passivation layer is formed by the surface defects of the perovskite single crystal and the 1 X 1 the structure formed by the combination; The perovskite crystal does not contain A that is not combined with the surface defects of the perovskite single crystal. 1 X 1 ; The A 1 One or more of ammonium cation, methylamine cation, formamidinium cation, cesium ion, rubidium ion, dimethylamine cation, ethylamine cation, propylamine cation, butylamine cation, hexamethylenediamine cation, phenylethylamine cation and adamantaneamine cation; The X 1 It is a halide ion, a thiocyanate ion or a sulfate ion.

2. The perovskite crystal according to claim 1, wherein The thickness of the passivation layer is 0.1-3 nm; and / or, said A 1 One or more of ammonium cation, methylamine cation, formamidinium cation, cesium ion and rubidium ion; and / or, when the X 1 When the ion is a halide ion, the halide ion is a fluoride ion, an iodide ion, a bromide ion or a chloride ion; And / or, the perovskite single crystal is a three-dimensional perovskite, a two-dimensional perovskite, a two-dimensional and three-dimensional mixed perovskite, a zero-dimensional perovskite, or a double perovskite; When the perovskite single crystal is a three-dimensional perovskite, the molecular formula of the three-dimensional perovskite is ABX3; When the perovskite single crystal is a two-dimensional perovskite and / or a two-dimensional and three-dimensional mixed perovskite, the molecular formula of the two-dimensional perovskite and the two-dimensional and three-dimensional mixed perovskite is M2A n-1 B n X 3n+1 , where n is a positive integer; When the perovskite single crystal is a zero-dimensional perovskite, the zero-dimensional perovskite molecular formula is A3C2X9; When the perovskite single crystal is a double perovskite, the double perovskite molecular formula is A2CDX6; The A is one or more of an ammonium cation, a methylamine cation, a formamidinium cation, a dimethylamine cation, a cesium ion, and a rubidium ion; the B is one or more of a lead divalent cation, a tin divalent cation, and a germanium divalent cation; the C is one or more of a bismuth trivalent cation, an antimony trivalent cation, an aluminum trivalent cation, an indium trivalent cation, and a gallium trivalent cation; the D is one or more of a silver monovalent cation, a lithium monovalent cation, a sodium monovalent cation, a potassium monovalent cation, and a rubidium monovalent cation; the X is one or more of an iodide ion, a bromide ion, and a chloride ion; and the M is one or more of a phenylethylamine cation, an ethylamine cation, a propylamine cation, a butylamine cation, a hexamethylenediamine cation, and an adamantaneamine cation.

3. The perovskite crystal according to claim 2, wherein The molecular formula of the perovskite single crystal is CH3NH3PbI3; and / or, said A 1 X 1 It is CH3NH3I.

4. A method for preparing a perovskite single crystal, characterized in that: It includes the following steps: Contains A 1 X 1 The solution is coated on the surface of the perovskite single crystal to form a passivation layer; The perovskite crystal does not contain A that is not bound to the surface defects of the perovskite single crystal 1 X 1 ; The A 1 X 1 For not excessive or excessive; when the A 1 X 1 When the amount is excessive, it also includes removing the excess A 1 X 1 Steps; The A 1 X 1 As claimed in any one of claims 1 to 3.

5. The method according to claim 4, wherein The perovskite single crystal has surface defects; and / or the perovskite single crystal is defined as described in claim 2 or 3; and / or, containing said A 1 X 1 In the solution, A 1 X 1 The concentration is less than 20 mg mL -1 ; and / or, containing said A 1 X 1 The solvent in the solution is one or more of isopropanol, methanol, sec-butanol, toluene, chlorobenzene and dichloromethane; And / or, the coating method is spin coating; the spin coating speed is 1000-5000 rpm, and the spin coating time is 5-60 s; and / or, removal of excess A 1 X 1 The operation is to apply a solvent; the coating method is spin coating; the spin coating speed is 1000-5000rpm; the spin coating time is 5-60s; the coating solvent is a solvent containing the A 1 X 1 The solvent used for the solution; And / or, the method further comprises post-processing; the post-processing is annealing; the temperature of the annealing is 40-200° C.; the time of the annealing is 1 second to 30 minutes; And / or, the perovskite single crystal is produced by a high-temperature sintering method, a vapor deposition method, an anti-solvent method, a solution heating method, a solution cooling method, or a spatially confined heating crystallization method, or a single crystal sheet is obtained by a one-time direct growth forming and cutting and polishing method; The spatially confined temperature crystallization method comprises the following steps: a structure including a second hydrophobic substrate layer, a perovskite precursor solution layer and a first hydrophobic substrate layer is subjected to heat treatment in sequence to obtain the perovskite single crystal; the structure is prepared by the following method: a perovskite precursor solution is dropped onto the first hydrophobic substrate, and a second hydrophobic substrate is placed on the perovskite precursor solution.

6. The method according to claim 5, wherein The perovskite precursor solution is prepared by the following method: a solute capable of generating a perovskite precursor and a solvent are mixed and stirred; the stirring temperature is 25-80° C.; the stirring time is 2-24 hours; The solutes capable of generating a perovskite precursor include "AX and BX2" or "AX, MX and BX2" or "AX, CX3" or "AX, CX3 and DX"; the definitions of A, B, C, D, X and M are as described in claim 2 or 3; When the solute that can generate a perovskite precursor includes "AX and BX2", the molar ratio of the AX and BX2 is 1:1; when the solute that can generate a perovskite precursor includes "AX, MX and BX2", the molar ratio of the AX, the MX and the BX2 is 2:1:1; when the solute that can generate a perovskite precursor includes "AX, CX3", the molar ratio of the AX and CX3 is 3:2; when the solute that can generate a perovskite precursor includes "AX, CX3 and DX", the molar ratio of the AX, the CX3 and the DX is 2:1:1; And / or, in the perovskite precursor solution, the concentration of the perovskite precursor is 1-2.5 mol·L -1 ; and / or, the solvent in the perovskite precursor solution is one or more of N,N-dimethylformamide, γ-butyrolactone and dimethyl sulfoxide; And / or, the first hydrophobic substrate and the second hydrophobic substrate are glass substrates coated with a hydrophobic agent; the hydrophobic agent is one or more of 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane, 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane, poly[bis(4-phenyl)(2, 4, 6-trimethylphenyl)amine], trifluoropropyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropylmethyldimethoxysilane, per(heptadecafluorodecyltrimethoxysilane), per(heptadecafluorodecyltriethoxysilane), per(tridecafluorooctyltrimethoxysilane and per(tridecafluorooctyltriethoxysilane); and / or, before the perovskite precursor solution is dropped onto the first hydrophobic substrate, the first hydrophobic substrate is preheated; the preheating temperature is 25-100° C.; And / or, in the spatially confined temperature rising crystallization method, the temperature of the heat treatment is 50-150° C.; and / or, in the spatially confined temperature rising crystallization method, the time of the heat treatment is 1-100 hours.

7. A surface passivation-modified perovskite single crystal, characterized in that: The perovskite single crystal is obtained by the preparation method of any one of claims 4 to 6.

8. Use of the perovskite crystal according to any one of claims 1 to 3 or the surface passivated modified perovskite single crystal according to claim 7 as an active layer in a radiation detector; wherein: The radiation detector is a coplanar structure radiation detector.

9. An X-ray radiation detector, characterized in that: It includes an active layer and an interdigitated electrode layer formed by a positive electrode layer and a negative electrode layer, wherein: The active layer is the perovskite crystal according to any one of claims 1 to 3 or the surface-passivated modified perovskite single crystal according to claim 7.

10. The X-ray radiation detector according to claim 9, wherein: in, The radiation detector is a coplanar structure radiation detector; And / or, the interdigitated electrode layer is formed by the positive electrode layer and the negative electrode layer being on the same side of the active layer, and the positive electrode layer and the negative electrode layer are not in direct contact; And / or, the interdigital electrode layer includes a conductive layer and an interface layer, or only a conductive layer; wherein the conductive layer material of the interdigital electrode layer is carbon or metal, and the metal is Cu, Au, Ag, Ga, In, Al, Pt, Ti, Bi or Cr, or a multilayer metal structure composed of the above metals; the interface layer material of the interdigital electrode layer is C60, C70, BCP, PCBM, copper phthalocyanine, cuprous thiocyanate, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, tris(4-carbazol-9-ylphenyl)amine, 9,9'-(1,3-phenyl)di-9H-carbazole, 4-[1-[4-[bis(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline, 2,3,5 ,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, polystyrene, polymethyl methacrylate, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-β-(aminoethyl)γ-aminopropylmethyldiethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, cysteine, taurine, L-penicillamine, TiO X ,MoO X , V2O5, WO3, LiF or Ca, or a multilayer structure of the above materials; the two interface layers of the interdigitated electrode layer are respectively the same or different materials or combinations mentioned above; the thickness of the interface layer of the interdigitated electrode layer is 1nm-100nm; the thickness of the conductive layer of the interdigitated electrode layer is 10nm-150μm.

11. A method for preparing an X-ray radiation detector, characterized in that: It includes the following steps: (1) Covering the active layer with a mask, depositing or printing interface and conductive materials, and removing the mask; the active layer is a perovskite single crystal; (2) The active layer is passivated and modified by the preparation method of the perovskite single crystal according to any one of claims 4 to 6.

12. The preparation method according to claim 11, characterized in that In step (1), the mask is an interdigitated mask; And / or, in step (1), the deposition rate of the material of the interdigital electrode layer is 0.1-5 ·s -1 ; and / or, in step (1), the deposition is performed in a vacuum coating machine; And / or, in step (1), the deposition method is vacuum thermal evaporation deposition, thermal evaporation, magnetron sputtering or spraying; And / or, in step (1), the printing method is screen printing; And / or, the parameters of the X-ray radiation detector are as described in claim 9 or 10.

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