Muon detector based on perovskite heterojunction and preparation method thereof

Abstract

The invention provides a perovskite heterojunction-based muon detector and a preparation method thereof, and belongs to the technical field of perovskite high-energy particle detection. The perovskite heterojunction-based muon detector comprises a first electrode layer, a perovskite heterojunction layer and a second electrode layer which are stacked from bottom to top, wherein the perovskite heterojunction layer comprises an MAPbBr3 perovskite layer and an APbBrnX1-n perovskite layer, n is greater than 0 and less than or equal to 3, A comprises at least one of formamidine ions, methylamine ions and cesium ions, and X comprises at least one of chloride ions and iodide ions; heavy atoms in the perovskite heterojunction layer are ionized into electron-hole pairs under the action of muons, and electrons and holes migrate to generate electric signals so as to realize detection of the muons.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite high-energy particle detection, and in particular relates to a muon detector based on a perovskite heterojunction and a preparation method thereof. Background Art

[0002] Muons are high-energy charged particles produced by the interaction of cosmic rays with the atmosphere. Muons lose less energy when passing through matter, which means that muons interact weakly with matter, making them difficult to detect. In addition, the average lifetime of a muon is 2.2 microseconds. Due to the short decay time of a muon, the number of muons that can be detected is limited.

[0003] Existing muon detectors mainly include scintillator detectors and gas ionization chamber detectors. Scintillators have the advantages of easy machining, flexible structural design and rapid signal readout, so scintillator detectors can meet the needs of various measurement and application scenarios. However, when measuring muon energy, scintillator detectors are affected by factors such as the characteristics of the scintillator material and the optical signal collection process, which makes the energy resolution of scintillator detectors relatively limited. In addition, the long scintillation lifetime of scintillator materials limits the ability to accurately measure muon signals with fast time structures. Gas ionization chamber detectors have the advantages of simple structure, large detection area and low cost. However, due to the complexity of the gas system in the gas ionization chamber detector, it is difficult to achieve long-term stable detection. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a muon detector based on perovskite heterojunction and a preparation method thereof, in order to at least partially solve the above technical problems. Therefore, the specific technical solutions provided by the present invention are as follows.

[0005] As a first aspect of the present invention, a muon detector based on a perovskite heterojunction is provided, comprising: a first electrode layer, a perovskite heterojunction layer and a second electrode layer stacked from bottom to top; wherein the perovskite heterojunction layer comprises a MAPbBr3 perovskite layer and an APbBr n X 1-n Perovskite layer, 0<n≤3, A includes at least one of formamidinium ion, methylamine ion, and cesium ion, and X includes at least one of chloride ion and iodine ion; heavy atoms in the perovskite heterojunction layer are ionized into electron-hole pairs under the action of muons, and electrons and holes migrate to generate electrical signals to realize the detection of muons.

[0006] As a second aspect of the present invention, a method for preparing a muon detector based on a perovskite heterojunction is provided, comprising: preparing a MAPbBr3 perovskite layer by a solution method; growing APbBr on the surface of the MAPbBr3 perovskite layer; n X1-n Perovskite layer, MAPbBr3 titanium layer and APbBr n X 1-n The perovskite layer constitutes a perovskite heterojunction layer; a first electrode material is deposited on one side of the perovskite heterojunction layer to form a first electrode layer, and a second electrode material is deposited on the other side of the perovskite heterojunction layer to form a second electrode layer, thereby obtaining a muon detector based on a perovskite heterojunction; wherein 0<n≤3, A includes at least one of formamidinium ions, methylamine ions, and cesium ions, and X includes at least one of chloride ions and iodine ions.

[0007] Based on the above technical solution, a muon detector based on a perovskite heterojunction and a preparation method thereof provided by the present invention have at least one of the following beneficial effects.

[0008] (1) In the embodiments of the present invention, the muon detector based on the perovskite heterojunction provided by the present invention (hereinafter referred to as the detector) is essentially an ionization chamber whose working medium is a solid. The heavy atoms in the perovskite heterojunction layer are ionized into electron-hole pairs under the action of muons, and the electrons and holes migrate to generate electrical signals to detect muons. The perovskite heterojunction structure can promote the separation of carriers and reduce the recombination of electron-hole pairs, thereby improving the detection efficiency of the detector. The perovskite heterojunction layer is composed of a higher density MAPbBr3 perovskite layer and an APbBr n X 1-n The perovskite layer allows the perovskite heterojunction layer to interact more with muons, thereby improving the detection efficiency; the average ionization energy of carriers in the perovskite heterojunction layer is only 1 / 10 of that of the gas, so it has a higher energy resolution and better energy linear response than the gas ionization chamber detector; the perovskite heterojunction layer has a relatively fast carrier transmission speed and a short lifetime, which enables it to provide a fast signal response, which is very important for measuring time-related information such as the arrival time and decay time of muons.

[0009] (2) In an embodiment of the present invention, a MAPbBr3 perovskite layer is prepared by a solution method, and an APbBr is grown thereon. n X 1-n Perovskite layer, MAPbBr3 titanium layer and APbBr n X 1-n The perovskite layer constitutes a perovskite heterojunction layer. Since the muon flux is low, a detector with a larger area needs to be set to detect muons. The present invention grows a perovskite heterojunction layer by a solution method to grow a larger area, uniform, and higher quality perovskite heterojunction layer to achieve large-area detection of muons. The preparation method of the muon detector based on the perovskite heterojunction provided by the present invention has the advantages of low cost, easier preparation, and easy large-area detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the structure of a muon detector based on a perovskite heterojunction in an embodiment of the present invention;

[0011] Figure 2 MAPbBr3 / MAPbBr obtained in Example 1 of the present invention 2.94 Cl 0.06 Physical picture of perovskite heterojunction layer;

[0012] Description of reference numerals:

[0013] 10: Perovskite heterojunction layer; 11: MAPbBr3 perovskite layer; 12: APbBr n X 1-n Perovskite layer; 13: electron transport layer; 14: hole transport layer.

[0014] 20: first electrode layer;

[0015] 30: Second electrode layer. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0017] Muons are high-energy charged particles that have the characteristics of strong penetrating power and small interaction with matter. Currently commonly used muon detectors mainly include scintillator detectors and gas ionization chamber detectors. The gas system in the gas ionization chamber detector is relatively complex, and it is difficult to maintain the long-term stability of the detector performance under changing temperature and pressure environments; the long scintillation lifetime of the scintillator material in the scintillator detector limits the ability to accurately measure the muon signal with a fast time structure. Based on this, the present invention provides a muon detector based on a perovskite heterojunction, which is essentially an ionization chamber with a solid working medium, and has the advantages of good energy resolution, fast time response, small size, low operating voltage and current, and high linear response.

[0018] Figure 1 Schematic diagram of the structure of a muon detector based on a perovskite heterojunction in an embodiment of the present invention.

[0019] As a first aspect of the present invention, a muon detector based on a perovskite heterojunction is provided, such as Figure 1 As shown, it includes: a first electrode layer 20, a perovskite heterojunction layer 10 and a second electrode layer 30 stacked from bottom to top; wherein the perovskite heterojunction layer 10 includes a MAPbBr3 perovskite layer 11 and an APbBr n X 1-nPerovskite layer 12, 0<n≤3, A includes at least one of formamidinium ion, methylamine ion, and cesium ion, and X includes at least one of chloride ion and iodine ion; heavy atoms in the perovskite heterojunction layer 10 are ionized into electron-hole pairs under the action of muons, and electrons and holes migrate to generate electrical signals to realize the detection of muons.

[0020] In the embodiment of the present invention, the muon detector based on the perovskite heterojunction provided by the present invention is essentially an ionization chamber whose working medium is a solid. The heavy atoms in the perovskite heterojunction layer 10 are ionized into electron-hole pairs under the action of muons, and the electrons and holes migrate to generate electrical signals to detect muons. The perovskite heterojunction structure can promote the separation of carriers and reduce the recombination of electron-hole pairs, thereby improving the detection efficiency of the detector. The perovskite heterojunction layer 10 is composed of a relatively high-density MAPbBr3 perovskite layer 11 and an APbBr n X 1-n The perovskite layer 12 enables the perovskite heterojunction layer 10 to interact more with muons, thereby improving the detection efficiency; the average ionization energy of carriers in the perovskite heterojunction layer 10 is only 1 / 10 of that of the gas, so it has a higher energy resolution and a better energy linear response; the perovskite heterojunction layer 10 has a relatively fast carrier transmission speed and a short lifetime, so it can provide a fast signal response, which is very important for measuring time-related information such as the arrival time and decay time of muons.

[0021] According to an embodiment of the present invention, continue as Figure 1 As shown, the above muon detector based on perovskite heterojunction further includes: an electron transport layer 13 and a hole transport layer 14, the electron transport layer 13 and the hole transport layer 14 are independent and located on different sides of the perovskite heterojunction layer. Figure 1 The positions of the electron transport layer 13 and the hole transport layer 14 are only illustrative, and are not intended to limit the present invention. The positions of the electron transport layer 13 and the hole transport layer 14 depend on the specific detector performance requirements and the properties of the perovskite material. The electron transport material and the hole transport material that are selectively used and matched with the energy level of the perovskite heterojunction layer, and the presence of the electron transport layer 13 and the hole transport layer 14 can improve the efficiency and response of the detector. The main function of the electron transport layer 13 is to promote the transmission and collection of electrons generated by the interaction of muons with the perovskite heterojunction layer 10. The main function of the hole transport layer 14 is to promote the transmission and collection of holes generated by the interaction of muons with the perovskite heterojunction layer 10. The first electrode layer 20 and the second electrode layer 30 are respectively located on the side of the hole transport layer 14 and the electron transport layer 13 away from the perovskite heterojunction layer 10, and the electrons and holes are respectively transmitted to the second electrode layer 30 and the first electrode layer 20 through the electron transport layer 13 and the hole transport layer 14, generating electrical signals and transmitting the electrical signals to the outside world.

[0022] As a second aspect of the present invention, a method for preparing a muon detector based on a perovskite heterojunction is provided, comprising: preparing a MAPbBr3 perovskite layer by a solution method; growing APbBr on the surface of the MAPbBr3 perovskite layer; n X 1-n Perovskite layer, MAPbBr3 titanium layer and APbBr n X 1-n The perovskite layer constitutes a perovskite heterojunction layer; a first electrode material is deposited on one side of the perovskite heterojunction layer to form a first electrode layer, and a second electrode material is deposited on the other side of the perovskite heterojunction layer to form a second electrode layer, thereby obtaining a muon detector based on a perovskite heterojunction; wherein 0<n≤3, A includes at least one of formamidinium ions, methylamine ions, and cesium ions, and X includes at least one of chloride ions and iodine ions.

[0023] In an embodiment of the present invention, a MAPbBr3 perovskite layer is prepared by a solution process, and an APbBr is grown thereon. n X 1-n Perovskite layer, MAPbBr3 titanium layer and APbBr n X 1-n The perovskite layer constitutes a perovskite heterojunction layer. Since the muon flux is low, a detector with a larger area needs to be set to detect muons. The present invention grows a perovskite heterojunction layer by a solution method to grow a larger area, uniform, and higher quality perovskite heterojunction layer to achieve large-area detection of muons. The preparation method of the muon detector based on the perovskite heterojunction provided by the present invention has the advantages of low cost, easier preparation, and easy large-area detection.

[0024] According to an embodiment of the present invention, preparing a MAPbBr3 perovskite layer by a solution method includes: adding methylamine bromide and lead bromide to N,N-dimethylformamide at a molar ratio of 1:0.7-1 and mixing them evenly to obtain a first precursor solution; placing a MAPbBr3 seed crystal in the first precursor solution, and growing a MAPbBr3 perovskite layer by heating. Wherein, MAPbBr3 is a single crystal. The concentration of methylamine bromide and lead bromide in the first precursor solution is 1-1.5mmol / L.

[0025] According to an embodiment of the present invention, MAPbBr3 seed crystals are obtained by the following method: a first precursor solution is heated at 60-80°C for 20-50 minutes for crystallization, and crystals with regular morphology are selected as MAPbBr3 seed crystals. The first precursor solution from which the MAPbBr3 seed crystals are grown can be filtered and then the MAPbBr3 single crystals can be grown, but the present invention is not limited thereto.

[0026] According to an embodiment of the present invention, further, placing a MAPbBr3 seed crystal in a first precursor solution, and growing a MAPbBr3 perovskite layer by heating includes: placing a MAPbBr3 seed crystal in a first precursor solution, keeping the temperature at 20-40°C for 10-40 minutes, and then heating the solution from 40-70°C to 75-90°C within 2-150 hours to obtain a MAPbBr3 perovskite layer. The temperature increase rate is controlled to grow a high-quality MAPbBr3 single crystal.

[0027] According to an embodiment of the present invention, APbBr is grown on the surface of the MAPbBr3 perovskite layer. n X 1-n The perovskite layer comprises: adding lead bromide, PbX2, and ABr to N,N-dimethylformamide in proportion and mixing them evenly to obtain a second precursor solution; adding bromoacetic acid to dimethylformamide and mixing them evenly to obtain a ligand solution; adding a MAPbBr3 perovskite layer to the mixed solution formed by the second precursor solution and the ligand solution and heating the mixed solution to grow APbBr n X 1-n Perovskite layer, APbBr n X 1-n It is a single crystal.

[0028] In the embodiments of the present invention, due to the limitations of perovskite material manufacturing and processing, the existing perovskite detectors have high preparation costs, complex preparation processes, and are difficult to achieve large-area detection. The key to manufacturing a muon detector with excellent performance is to prepare a larger, uniform and high-quality perovskite heterolayer structure. The growth and crystallization process of perovskite crystals in solution is often difficult to achieve precise control. The use of the ligand bromoacetic acid to assist growth to obtain a perovskite heterojunction structure has low preparation costs and simple preparation processes. Bromoacetic acid (C2H3BrO2) reacts with the solvent dimethyl sulfoxide (DMSO) to form aldehyde acid, and the carbonyl group in the aldehyde acid can react with Pb in the second precursor solution. 2+ A stronger complexation is formed, thereby inhibiting nucleation, delaying crystallization, and obtaining perovskite crystals of better quality.

[0029] According to an embodiment of the present invention, the molar ratio of PbX2 to lead bromide is 0-1:1; the ratio of the molar amount of ABr to the molar sum of PbX2 and lead bromide is 0.7-1:1; the concentration of bromoacetic acid in the ligand solution is 15-30 mg / mL. The volume ratio of the second precursor solution to the ligand solution is 1:0-1.

[0030] According to an embodiment of the present invention, a MAPbBr3 perovskite layer is added to a mixed solution formed by a second precursor solution and a ligand solution and heated to grow an APbBr3 perovskite layer. n X 1-nThe perovskite layer comprises: adding the first perovskite layer to a mixed solution formed by a second precursor solution and a ligand solution, keeping the temperature at 60-70°C for 5-15 minutes, and then slowly heating the temperature to 75-80°C within 200-600 minutes to obtain APbBr n X 1-n Perovskite layer.

[0031] According to an embodiment of the present invention, before depositing a first electrode material on one side of the perovskite heterojunction layer to form a first electrode layer and depositing a second electrode material on the other side of the perovskite heterojunction layer to form a second electrode layer, the method further includes: depositing an electron transport layer material on one side of the perovskite heterojunction layer to form an electron transport layer, and depositing a hole transport layer material on the other side of the perovskite heterojunction layer to form a hole transport layer. The hole transport layer material can be selected from poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PTAA), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS), cuprous thiocyanate (CuSCN), cuprous iodide (CuI), cuprous oxide (Cu2O), molybdenum oxide (MoO x ) and nickel oxide (NiO x ). The electron transport layer material can be selected from any one of titanium dioxide (TiO2), aluminum oxide (Al2O3), Spiro-OMeTAD, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) (TPBI), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), fullerene (C60) and lithium fluoride (LiF). The selection of electron transport layer materials and hole transport layer materials depends on their matching degree with the energy level of the perovskite heterojunction layer and the specific detector performance requirements, which is not limited in the present invention.

[0032] In an embodiment of the present invention, the first electrode material can be selected from any one of a conductive silicon wafer, an ITO or FTO conductive glass grown on a glass substrate, and a conductive metal, and the second electrode material can be selected from any one of a conductive metal. Among them, the conductive metal can be selected from single-layer metals such as gold, silver, platinum, etc., and can also be selected from multi-layer metals such as chromium / gold. It should be noted that the thickness of each structural layer in the muon detector based on the perovskite heterojunction is set according to the actual application requirements. For example, the thickness of the perovskite heterojunction layer is 1-10mm, the thickness of the electron transport layer is 5-80nm, the thickness of the hole transport layer is 5-80nm, the thickness of the first electrode layer is 40-150nm, and the thickness of the second electrode layer is 40-150nm. The present invention does not limit this.

[0033] Specifically, the preparation method of the muon detector based on perovskite heterojunction provided by the present invention is as follows.

[0034] Step 1: Dissolve lead bromide (PbBr2) and methylamine bromide (MABr) in N,N-dimethylformamide (DMF) at a molar ratio of 0.7-1:1, shake and filter into a container, and place a silicon wafer or conductive glass of appropriate size at the bottom of the container. The silicon wafer or conductive glass serves as the growth substrate of the perovskite crystal and can be removed after the perovskite single crystal is grown, or it can be left as the first electrode layer.

[0035] Step 2: Dissolve lead bromide (PbBr2) and methylamine bromide (MABr) in N,N-dimethylformamide (DMF) at a molar ratio of 0.7-1:1, filter into a container after shaking, place the entire container on a hot table, and keep it warm at 60-80°C for 20-50 minutes. A large number of MAPbBr3 seed crystals will appear in the container, and select crystals with regular morphology for subsequent single crystal growth.

[0036] Step 3: Take a MAPbBr3 seed crystal and place it on the silicon wafer in the container in step 1, and place the entire container on a hot table. Keep it warm at 20-40°C for 10-40 minutes to allow the MAPbBr3 seed crystal to partially dissolve. Then, raise the temperature from 40-70°C to 75-90°C within 2-150 hours to obtain a MAPbBr3 single crystal.

[0037] Step 4: Lead bromide (PbBr2), PbX2 (X is one or more of Cl or I), ABr (A is FA + 、MA + , Cs + One or more of the above), wherein the molar ratio of PbX2 to lead bromide is 0-1:1, and the ratio of the molar amount of ABr to the molar sum of PbX2 and lead bromide is 0.7-1:1, dissolved in a mixed solution of a certain ratio of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) containing bromoacetic acid (C2H3BrO2). After shaking, filter into a container, and place a silicon wafer or conductive glass of appropriate size at the bottom of the container.

[0038] Step 5: Place the MAPbBr3 single crystal in step 3 onto the silicon wafer in the container, and place the entire container on a hot plate and keep it at 60-70°C for 5-15 minutes, then slowly heat it to 75-80°C within 200-600 minutes to obtain APbBr n X 1-n Single crystal. MAPbBr3 single crystal and APbBr n X 1-n Single crystal composition MAPbBr3 / APbBr n X 1-n Perovskite heterojunction layer.

[0039] Step 6: Spin coating or thermal evaporation on MAPbBr3 / APbBr n X 1-n The electron transport layer and the hole transport layer are prepared on the upper and lower surfaces of the perovskite heterojunction layer.

[0040] Step 7: Away MAPbBr3 / APbBr in the electron transport layer and hole transport layer n X 1-n Electrode materials are deposited on the upper and lower surfaces of the perovskite heterojunction layer to obtain a first electrode layer and a second electrode layer, thereby obtaining a muon detector based on the perovskite heterojunction.

[0041] The present invention is further described below by examples and related test experiments. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is obvious that one or more embodiments may also be implemented without these specific details. And, in the absence of conflict, the details in the following embodiments may be combined into other feasible embodiments at will. All instruments, consumables and reagents in the following examples, if not otherwise specified, may be obtained from commercial sources.

[0042] Example 1

[0043] In this Example 1, a muon detector based on a perovskite heterojunction was prepared according to the following method, and muon detection was performed.

[0044] Step 1: Weigh 0.32248 g of methyl ammonium bromide (MABr) and 0.88082 g of lead bromide (PbBr2) and put them into a 5 mL small glass bottle. Take 2 mL of N,N-dimethylformamide (DMF) and inject it into the mixed powder of MABr and PbBr2 to form a first precursor solution. After shaking for 8 hours, use a polytetrafluoroethylene filter membrane with a pore size of 0.22 μm to filter the first precursor solution and transfer the solution to a 20 mL small glass bottle, and place a silicon wafer of appropriate size at the bottom of the glass bottle.

[0045] Step 2: Take a small MAPbBr3 seed crystal with regular morphology and place it on the silicon wafer in the glass bottle, and place the entire glass bottle on a hot plate and keep it warm at 40°C for 20 minutes. After the insulation is completed, the hot plate is heated from 70°C to 75°C within 210 minutes to obtain a MAPbBr3 perovskite layer.

[0046] Step 3: Weigh 0.02500 g of bromoacetic acid (C2H3BrO2) and dissolve it in 1 mL of dimethyl sulfoxide (DMSO). Shake until the solution changes color significantly to obtain a ligand solution.

[0047] Step 4: Weigh 0.32248 g of methyl ammonium bromide (MABr), 0.85439 g of lead bromide (PbBr2) and 0.02047 g of lead chloride (PbCl2) and put them into a 5 mL small glass bottle. Take 1900 mL of N,N-dimethylformamide (DMF) and 100 μL of the ligand solution in step 3 and inject them into the mixed powder to form a mixed solution. After shaking for 8 hours, filter the mixed solution through a polytetrafluoroethylene filter membrane with a pore size of 0.22 μm and transfer the mixed solution to a 20 mL small glass bottle. Place a silicon wafer of appropriate size at the bottom of the glass bottle.

[0048] Step 5: Place the MAPbBr3 perovskite layer in step 2 onto the silicon wafer in step 4 and keep it at 70°C for 10 min, then increase the temperature from 70°C to 75°C within 300 min to obtain MAPbBr 2.94 Cl 0.06 After the heating is completed, the MAPbBr3 perovskite layer and the MAPbBr 2.94 Cl 0.06 Perovskite layer composition MAPbBr3 / MAPbBr 2.94 Cl 0.06 Perovskite heterojunction layer.

[0049] Step 6: When the heating time is over, quickly use tweezers to remove the Figure 2 MAPbBr3 / MAPbBr 2.94 Cl 0.06 The perovskite heterojunction layer was taken out, and the solution on the surface of the perovskite heterojunction was blown dry with a nitrogen gun.

[0050] Step 7: Prepare MAPbBr3 / MAPbBr 2.94 Cl 0.06 The C60 / BCP electron transport layer and molybdenum oxide (MoO) were prepared on the upper and lower surfaces of the perovskite heterojunction layer by spin coating or vacuum thermal evaporation. x ) hole transport layer.

[0051] Step 8: Vacuum thermal evaporation of 80 nm gold was performed on the surface of the prepared electron transport layer and hole transport layer. The resulting structure is: Au / MoOx / MAPbBr3 / MAPbBr 2.94 Cl 0.06 / C60 / BCP / Au perovskite heterojunction-based muon detector.

[0052] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A muon detector based on a perovskite heterojunction, characterized in that: include: A first electrode layer, a perovskite heterojunction layer, and a second electrode layer stacked from bottom to top; The perovskite heterojunction layer includes a MAPbBr3 perovskite layer and an APbBr n X 1-n Perovskite layer, 0<n≤3, A includes at least one of formamidinium ion, methylamine ion, and cesium ion, and X includes at least one of chloride ion and iodide ion; The heavy atoms in the perovskite heterojunction layer are ionized into electron-hole pairs under the action of muons, and the electrons and holes migrate to generate electrical signals to detect the muons.

2. The detector according to claim 1, characterized in that: Also includes: An electron transport layer and a hole transport layer, wherein the electron transport layer and the hole transport layer are independent and located on different sides of the perovskite heterojunction layer.

3. A method for preparing a detector as claimed in any one of claims 1 to 2, characterized in that: include: Preparation of MAPbBr3 perovskite layer by solution method; APbBr3 is grown on the surface of the MAPbBr3 perovskite layer. n X 1-n perovskite layer, the MAPbBr3 perovskite layer and the APbBr n X 1-n The perovskite layer constitutes a perovskite heterojunction layer; Depositing a first electrode material on one side of the perovskite heterojunction layer to form a first electrode layer, and depositing a second electrode material on the other side of the perovskite heterojunction layer to form a second electrode layer, thereby obtaining a muon detector based on the perovskite heterojunction; Wherein, 0<n≤3, A includes at least one of formamidinium ion, methylamine ion and cesium ion, and X includes at least one of chloride ion and iodide ion.

4. The method according to claim 3, characterized in that The method of preparing the MAPbBr3 perovskite layer by a solution method comprises: Adding methylamine bromide and lead bromide to N,N-dimethylformamide at a molar ratio of 1:0.7-1 and mixing well to obtain a first precursor solution; A MAPbBr3 seed crystal is placed in the first precursor solution, and a MAPbBr3 perovskite layer is grown by heating, wherein the MAPbBr3 is a single crystal.

5. The method according to claim 4, characterized in that The MAPbBr3 seed crystal is obtained by the following method: The first precursor solution is heated at 60-80° C. for 20-50 min for crystallization, and crystals with regular morphology are selected as MAPbBr3 seed crystals.

6. The method according to claim 4, characterized in that The step of placing the MAPbBr3 seed crystal in the first precursor solution and growing the MAPbBr3 perovskite layer by heating comprises: The MAPbBr3 seed crystal is placed in the first precursor solution, kept at 20-40°C for 0-40 minutes, and then heated from 40-70°C to 75-90°C within 2-150 hours to obtain a MAPbBr3 perovskite layer.

7. The method according to claim 3, characterized in that The APbBr3 perovskite layer is grown on the surface of the MAPbBr3 perovskite layer. n X 1-n The perovskite layer consists of: Adding lead bromide, PbX2, and ABr into N,N-dimethylformamide in proportion and mixing evenly to obtain a second precursor solution; Adding bromoacetic acid into dimethyl sulfone and mixing well to obtain a ligand solution; The MAPbBr3 perovskite layer is added to a mixed solution formed by the second precursor solution and the ligand solution and heated to grow APbBr n X 1-n Perovskite layer, the APbBr n X 1-n It is a single crystal.

8. The method according to claim 7, characterized in that The molar ratio of PbX2 to lead bromide is 0-1:1; The ratio of the molar amount of ABr to the molar sum of PbX2 and lead bromide is 0.7-1:1; The concentration of the bromoacetic acid in the ligand solution is 15-30 mg / mL.

9. The method according to claim 7, characterized in that: The MAPbBr3 perovskite layer is added to a mixed solution formed by the second precursor solution and the ligand solution and heated to grow APbBr3 n X 1-n The perovskite layer consists of: The first perovskite layer is added to the mixed solution formed by the second precursor solution and the ligand solution, and after being kept at 60-70°C for 5-15 minutes, the temperature is slowly raised to 75-80°C within 200-600 minutes to obtain APbBr n X 1-n Perovskite layer.

10. The method according to any one of claims 4 to 9, characterized in that: Before depositing a first electrode material on one side of the perovskite heterojunction layer to form a first electrode layer and depositing a second electrode material on the other side of the perovskite heterojunction layer to form a second electrode layer, the method further comprises: An electron transport layer material is deposited on one side of the perovskite heterojunction layer to form an electron transport layer, and a hole transport layer material is deposited on the other side of the perovskite heterojunction layer to form a hole transport layer.

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