A dual-mode asymmetric P-I-N perovskite radiation detector and a preparation method thereof

Abstract

A dual-mode asymmetric P-I-N perovskite radiation detector and its fabrication method are disclosed, belonging to the field of radiation detector technology. The method first involves preparing a perovskite single-crystal precursor solution. A small amount of this solution is used for seed crystal growth at a constant temperature, with the seed crystal serving as the seed for CsPbBr3 single-crystal growth on a P-type substrate. Next, a MAPbBr3 solution is prepared, and MAPbBr3 single crystals are grown to form the I layer. Finally, MAPbBr3 (Bi) is prepared... 3+ A doped solution was used to grow MAPbBr3 (Bi) as the N-layer. 3+ A dual-mode asymmetric P-I-N perovskite radiation detector is obtained by fabricating top and bottom electrodes using a doped single crystal. This invention utilizes the forward conduction and reverse cutoff characteristics of the P-I-N structure. When a negative voltage is applied to the N layer for forward bias, X-rays incident on the P layer are used for radiation detection, exciting the photoconductivity gain and achieving a sensitivity far exceeding that of CsPbBr3 single crystals; simultaneously, MAPbBr3 (Bi 3+ The doped single crystal has a natural shielding effect on soft X-rays, enabling high-sensitivity detection of hard X-rays in the I layer when X-rays are incident on the N layer with positive pressure and reverse P-I-N bias.

Description

Technical Field

[0001] This invention belongs to the field of radiation detector technology, specifically relating to a dual-mode asymmetric PIN perovskite radiation detector and its fabrication method. Background Technology

[0002] The space radiation environment is exceptionally complex, filled with high-flux soft X-rays from solar flares, highly penetrating high-energy hard X-rays from space, and gamma rays, posing serious threats to the safety of spacecraft electronic systems and the health of astronauts. Therefore, developing radiation detection terminals with energy discrimination, direction recognition, high sensitivity, and extremely low power consumption is a major strategic requirement in the field of deep space exploration. Lead halide perovskite single crystals, with their heavy atomic composition, long charge carrier diffusion distance, and low-cost solution-processable characteristics, have become revolutionary candidate materials for next-generation high-performance high-energy ray detectors. In recent years, X-ray detectors based on perovskite single crystals have reached or even surpassed the sensitivity and detection limit levels of traditional commercial scintillators and semiconductor detectors. However, facing the extreme and variable space environment, traditional perovskite detectors exhibit inherent deficiencies in functional singularity and long-term operational stability. This mismatch between the demands of application scenarios and the performance of existing devices has become an important research direction driving innovation in the architecture of space radiation detectors.

[0003] Traditional perovskite X-ray detectors typically employ symmetrical photoconductive configurations. A key challenge with this type of device is its reliance on a continuously applied high bias voltage to extract photogenerated carriers. Under the combined effects of long-term high voltage and radiation fields, the relatively weak lattice binding within the perovskite readily induces long-range disordered migration of halide ions and vacancies, leading to severe ion polarization and space charge shielding at the heterojunction interface. This results in drastic fluctuations in dark current, baseline drift, and a significant decrease in detection sensitivity over time, ultimately compromising the device's long-term operational stability. In space applications, simultaneously achieving high-sensitivity transient alarms for weak soft X-rays and radiation dose monitoring for hard X-rays is clearly beyond the capabilities of traditional detection modes driven by a single DC high voltage. The contradiction between high sensitivity and long-term stability, as well as multi-spectral detection, has become a formidable technological hurdle.

[0004] To simultaneously overcome the "stability-high sensitivity" dilemma of perovskite detectors and endow them with dual-mode detection capabilities, constructing a macroscopically asymmetric PIN all-perovskite crystal configuration has become a highly promising solution. This asymmetric architecture, by introducing extreme thickness asymmetry, creates a natural X-ray energy filtering and direction decoupling mechanism in physical space. This leads to distinctly different dual-mode detection mechanisms: utilizing the thick-layer "dead zone" filtering effect to achieve sustained high-sensitivity detection of hard X-rays under a high reverse bias voltage of the PIN structure; and utilizing the photoconductivity gain mechanism through the forward bias voltage of the PIN structure to excite high-sensitivity detection of both soft and hard X-rays in the P-layer. This mechanism, through the synergistic regulation of structural asymmetry and ion dynamics, achieves a comprehensive leap in device performance, providing a perfect solution to breaking the inherent contradiction of "multi-band discrimination - ultra-low power consumption - extremely high stability" in space radiation detection. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-mode asymmetric PIN perovskite radiation detector and its fabrication method.

[0006] The method for fabricating a dual-mode asymmetric PIN perovskite radiation detector according to the present invention comprises the following steps:

[0007] 1) Weigh CsBr and PbBr2 powders with a molar ratio of 1:2, dissolve them in DMSO (dimethyl sulfoxide) solution, stir at 40~60℃ for 12~15h until the powder is completely dissolved, let stand and remove the precipitate to obtain a clear CsPbBr3 solution, i.e. perovskite single crystal precursor solution.

[0008] 2) A small amount of the precursor solution obtained in step 1) is drawn out with a syringe and seeded crystals are grown in the small amount of solution at a constant temperature. Then, a seed crystal with good shape, no cracks and transparent is selected and placed in a crystal growth bottle containing the remaining perovskite single crystal precursor solution. The bottle cap is loosened to allow the solvent to evaporate slowly until a CsPbBr3 single crystal with a thickness of 2~4mm is grown. The crystal is taken out, dried with a nitrogen gun, and annealed in an oven and gradually cooled to room temperature to obtain a CsPbBr3 single crystal as a P-type substrate.

[0009] 3) Take out the grown CsPbBr3 single crystal, blow off the residual solution on its surface with a nitrogen gun, and polish the surface of the CsPbBr3 single crystal with DMSO polishing liquid containing diamond powder to smooth the bottom surface that has pitted due to the container during natural growth; then, take an appropriate amount of PDMS encapsulating adhesive into the crystal growth bottle, immerse the lower half of the CsPbBr3 single crystal in PDMS, and place the crystal growth bottle on a hot stage at 70~80℃ for 10~20min to solidify the encapsulating adhesive to isolate the heterojunction growth solution;

[0010] 4) Weigh MABr and PbBr2 powders in a molar ratio of 1:1, dissolve them in DMF (N,N-dimethylformamide) solution, stir at room temperature for 12-15 hours until the powder is completely dissolved, remove the precipitate after standing to obtain a clear MAPbBr3 solution; then inject it into the crystal growth bottle of step 3), and grow a MAPbBr3 single crystal heterojunction at a constant temperature with the cap of the crystal growth bottle loosened; when the thickness of the in-situ grown MAPbBr3 single crystal heterojunction is 1.5-3.0 mm, take out the crystal, blow off the residual solution on the surface with a nitrogen gun, and anneal in an oven to gradually cool to room temperature, thereby growing a MAPbBr3 single crystal heterojunction as the I layer, i.e., the PI layer crystal, on the (001) surface of the CsPbBr3 single crystal as the P-type substrate.

[0011] 5) Polish the PI layer crystal obtained in step 4) with DMF polishing slurry containing diamond powder. Remove the excess crystal at the edge of the MAPbBr3 single crystal heterolayer that is epitaxially grown around the crystal until it is a regular cube of the same size as the CsPbBr3 single crystal substrate, which is beneficial to the growth of the next N-layer single crystal. Then, take an appropriate amount of PDMS encapsulant into the crystal growth bottle, place the MAPbBr3 crystal with the darker color of the PI layer crystal facing upward, and immerse the lower half of the PI layer crystal in PDMS. Place the crystal growth bottle on a hot plate and heat at 70~80℃ for 10~20 minutes to solidify the encapsulant to isolate the heterojunction growth solution.

[0012] 6) Weigh MABr and PbBr2 powders in a molar ratio of 1:1, and BiBr3 powder at 0.01% molar amount of PbBr2. Dissolve them in DMF (N,N-dimethylformamide) solution and stir magnetically at room temperature for 12-15 hours until the powders are completely dissolved to obtain clear MABr3 (BiBr2). 3+ The doped solution was then injected into the crystal growth flask in step 5), and homojunction interface growth was carried out at a constant temperature with the cap loosened; when the in-situ grown MAPbBr3 (Bi 3+ When the thickness of the doped single-crystal homojunction is 45~55μm, the crystal is removed, the residual solution on the surface is blown off with a nitrogen gun, and then annealed in an oven and gradually cooled to room temperature, thereby obtaining MAPbBr3 (Bi) as the N layer on the (001) surface of the PI layer crystal. 3+ Doped single-crystal homojunction, i.e., PIN three-layer crystal.

[0013] 7) Polish the PIN three-layer crystal obtained in step 6) with DMF polishing slurry containing diamond powder, and grind away the excess crystal at the edge to a regular cube with the same size as the CsPbBr3 single crystal substrate to form an asymmetric PIN perovskite crystal.

[0014] 8) The N-layer MAPbBr3(Bi) of the asymmetric PIN perovskite crystal obtained in step 7) 3+ A Cr electrode is prepared on the doped upper surface and the P-layer CsPbBr3 lower surface to obtain the dual-mode asymmetric PIN perovskite radiation detector.

[0015] Furthermore, in step 2), the isothermal temperature for seed crystal growth is 75~80℃, and the growth time is 2~3h; the isothermal temperature for growing CsPbBr3 single crystal is 75~80℃, and the growth time is 4~6 days.

[0016] In step 4), the isothermal temperature for heterojunction interface growth is 55~65℃.

[0017] In step 6), the isothermal temperature for the growth of the homojunction interface is 55~65℃.

[0018] A second aspect of the present invention is to provide a dual-mode asymmetric PIN perovskite radiation detector, which is prepared by the above method.

[0019] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0020] (1) N-layer MAPbBr3 (Bi 3+ After crystal doping, the asymmetric PIN structure exhibits the characteristic of being unresponsive to soft X-rays. Utilizing the high atomic number of perovskite, the N layer can filter out all soft X-rays in the incident irradiation, while hard X-rays can pass through the N layer and generate a photoelectric effect in the I layer, thereby achieving the function of hard X-ray detection without filters.

[0021] (2) When the N-layer is positively biased, the asymmetric PIN structure has good rectification characteristics and low noise and stability under high voltage.

[0022] (3) By utilizing the forward conduction and reverse cutoff characteristics of the PIN structure, when the N layer is negatively biased, the P layer is exposed to X-rays for radiation detection, which excites the photoconductivity gain and obtains a sensitivity much higher than that of CsPbBr3 single crystal.

[0023] (4) The dual-mode asymmetric PIN perovskite radiation detector prepared by the present invention can be further applied in space exploration. Attached Figure Description

[0024] Figure 1 These are local SEM images of the PIN perovskite crystal prepared in Example 1 of the present invention. The left image is the SEM image near the NI contact interface, and the right image is the SEM image near the IP contact interface.

[0025] like Figure 1 As shown, the PIN perovskite crystal is continuous at the Ni and I interfaces and on the surface of the epitaxially grown portion without internal grain boundaries, indicating that the in-situ epitaxially grown N and I layers and the CsPbBr3 crystal serving as the substrate are all single crystals.

[0026] Figure 2 This is a schematic diagram of the dual-mode asymmetric PIN perovskite radiation detector structure prepared in Example 1 of the present invention;

[0027] like Figure 2 As shown, asymmetric area metal electrodes are used to concentrate the electric field distribution inside the device and improve charge collection efficiency.

[0028] Figure 3 The image shows the dark current-voltage curve of the perovskite radiation detector prepared in Example 1 of this invention. The horizontal axis represents voltage (unit: volts), and the vertical axis represents dark current (unit: amperes). The curve was measured by an IV test system (which consists of a Keithley 2901B instrument, probe, and data acquisition software). During the test, a voltage was applied to the electrodes at both ends of the device in the dark state, and the current value was read at the same time.

[0029] like Figure 3 As shown, the asymmetric PIN perovskite radiation detector prepared in Example 1 exhibits good stability and voltage withstand capability, and still demonstrates good rectification performance under high voltage conditions. In the 20-30V range, a concave peak appears due to negative differential conductivity caused by ion migration.

[0030] Figure 4 This is a fitting graph of the N-face detection sensitivity of the perovskite radiation detector prepared in Example 1 of the present invention; measured by a radiation testing system (the system consists of a Keithley 2901B instrument, a MOXTEK microfocus X-ray source (model TUB00154-9I-W06), a probe station, and data acquisition software).

[0031] like Figure 4 As shown in the figure, the horizontal axis represents time (in seconds), and the vertical axis represents the detector current (in amperes). The test data was obtained from the radiation testing system. During the test, a voltage was applied across the device, the current was measured using a source meter, the X-ray source was turned on, and the device was irradiated with different dose rates while the device current was measured. The X-ray energy used in the test was 75 keV. Figure (a) shows the N-face (MAPbBr3 Bi) of the perovskite radiation detector under a bias voltage of 200V. 3+ (Doped surface) for 84.53 μGy s -1 238.8 μGy s -1 406.4 μGy s -1The X-ray dose response current curves. The current response value increases with increasing dose rate; (b) shows the current response value of the perovskite radiation detector N-face (MAPbBr3 Bi) at a bias voltage of 200V. 3+ (Doped surface) for 892.1 μGy s -1 731.1 μGy s -1 570.1 μGy s -1 The X-ray response current curve for the dose rate. The current response value increases with increasing dose rate; Figure (c) shows the sensitivity fitting plot of the perovskite radiation detector at a bias voltage of 200V. The radiation detection sensitivity of the perovskite radiation detector is the net photocurrent density (unit: μC Gy) representing the detector's photoresponse per unit dose rate. -1 cm -2 Sensitivity was calculated from the slope obtained by fitting the dose rate to the net photocurrent density at different corresponding doses using a first-order term curve. (c) Figure shows that the asymmetric PIN perovskite radiation detector prepared in Example 1 has good hard X-ray response capability, can still work stably under high pressure, and exhibits high sensitivity performance.

[0032] Figure 5 The fitting graph of the detection sensitivity of the P-face of the perovskite radiation detector prepared in Example 1 of the present invention; measured by the radiation testing system (the system consists of a Keithley 2901B instrument, a MOXTEK microfocus X-ray source (model TUB00154-9I-W06), a probe station, and data acquisition software).

[0033] like Figure 5 As shown in the figure, the horizontal axis represents time (in seconds), and the vertical axis represents the detector current (in amperes). The test data were obtained from the radiation testing system. During the test, a voltage was applied across the device, the current was measured using a source meter, the X-ray source was turned on, and the device was irradiated with different dose rates while the device current was measured. Figure (a) shows the effect of a 200V bias voltage on the P-plane (CsPbBr3 crystal plane) of the perovskite radiation detector at 84.53 μGy / s. -1 238.8 μGy s -1 406.4 μGy s -1 The X-ray dose response current curves. The current response value increases with increasing dose rate; (b) shows the response of the perovskite radiation detector P-plane (CsPbBr3 crystal plane) to 570.1 μGy s at a bias of 200 V. -1 731.1 μGy s -1 892.1 μGy s -1The X-ray dose response current curve. The current response value increases with increasing dose rate; Figure (c) shows the sensitivity fitting plot of the perovskite radiation detector at a bias voltage of 200V. The radiation detection sensitivity of the perovskite radiation detector (unit: μCGy) -1 cm -2 ) represents the net photocurrent density of the detector's photoresponse at a unit dose rate. Sensitivity is calculated from the slope obtained by fitting a curve of the dose rate and the net photocurrent density at different corresponding doses. Figure (c) shows that the asymmetric PIN perovskite radiation detector prepared in Example 1 has good X-ray response capability, can still work stably under high voltage, and exhibits high sensitivity performance. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the implementation of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] 1) Weigh 1.278 g of cesium bromide (CsBr) and 4.404 g of lead bromide (PbBr2) powder (the molar ratio of CsBr to PbBr2 is 1:2), add them to a glass bottle containing 10 mL of dimethyl sulfoxide (DMSO), and place a magnetic stir bar in the bottle; place the glass bottle on a magnetic stirring table, heat at 55 °C and stir magnetically for 12 h until the powder is completely dissolved, let stand and remove the precipitate to obtain a clear CsPbBr3 solution, i.e., perovskite single crystal precursor solution;

[0037] 2) Take 2 mL of the precursor solution obtained in step 1) into a small bottle using a syringe. Place the small solution in a constant temperature oven at 78°C and loosen the cap to allow the solvent to evaporate slowly for the growth of CsPbBr3 seed crystals. After 2 hours, select a seed crystal with a good shape, no cracks, and transparency and place it in a crystal growth bottle containing the remaining perovskite single crystal precursor solution. Place the bottle in a constant temperature oven at 78°C and loosen the cap to allow the solvent to evaporate slowly for the growth of CsPbBr3 single crystals for 5 days until a CsPbBr3 single crystal with a thickness of about 3 mm is grown. Take it out, dry it with a nitrogen gun, and anneal it in an oven and gradually cool it to room temperature to obtain a CsPbBr3 single crystal as a P-type substrate.

[0038] 3) Take out the grown CsPbBr3 single crystal, blow off the residual solution on its surface with a nitrogen gun, and polish the surface of the CsPbBr3 single crystal with DMSO polishing liquid containing diamond powder to smooth the bottom surface that has pitted due to the container during natural growth; then, take an appropriate amount of PDMS encapsulating adhesive into the crystal growth bottle, immerse the lower half of the CsPbBr3 single crystal in PDMS, and then place the crystal growth bottle on a hot plate at 80°C for 10 minutes to solidify the encapsulating adhesive to isolate the heterojunction growth solution.

[0039] 4) Take 0.672 g of methylamine bromide (MABr) and 2.202 g of lead bromide (PbBr2) powder (MABr to PbBr2 molar ratio of 1:1), add them to a glass bottle, add 5 mL of dimethylamide (DMF), and place a magnetic stir bar inside. Place the glass bottle on a magnetic stirring table and stir magnetically for 12 h at room temperature until the powder is completely dissolved. After standing, remove the precipitate to obtain a clear MAPbBr3 solution. Then pour the solution into the crystal growth bottle from step 3), place it in a constant temperature oven, and loosen the cap at 60°C to grow a MAPbBr3 single-crystal heterojunction in situ. When the thickness of the in-situ grown MAPbBr3 single-crystal heterojunction is 2.0 mm... When the crystal is mm, it is taken out, the residual solution on the surface is blown off with a nitrogen gun, and it is annealed in an oven and gradually cooled to room temperature, so as to grow a MAPbBr3 single crystal heterojunction as the I layer, i.e., the PI layer crystal, on the CsPbBr3 single crystal (001) surface as the P-type substrate.

[0040] 5) Polish the PI layer crystal obtained in step 4) using DMF polishing slurry containing diamond powder to remove excess crystals from the edges of the MAPbBr3 heterolayer that grew epitaxially around the crystal, reducing them to a regular cube of the same size as the CsPbBr3 single crystal substrate. This facilitates the growth of the next N-layer single crystal. Then, place an appropriate amount of PDMS encapsulant in the crystal growth bottle, with the darker MAPbBr3 crystal of the PI layer facing upwards, and immerse the lower half of the PI layer crystal in PDMS. Then, place the crystal growth bottle on a hot plate and heat at 80°C for 10 minutes to solidify the encapsulant to isolate the heterojunction growth solution.

[0041] 6) Take 0.672 g of methylamine bromide (MABr), 2.202 g of lead bromide (PbBr2) powder (MABr to PbBr2 molar ratio of 1:1), and 0.0003 g of BiBr3 powder, add them to a glass bottle, add 5 mL of dimethylamide (DMF), and place a magnetic stir bar in the bottle; place the glass bottle on a magnetic stirring table and stir at room temperature for 12 h until the powder is completely dissolved. After standing, remove the precipitate to obtain clear MAPbBr3 (BiBr3). 3+The solution was then injected into the crystal growth flask in step 5), and the homojunction interface was grown at a constant temperature of 60°C with the cap loosened; when the in-situ grown MAPbBr3(Bi) 3+ When the homojunction thickness is 50 μm, the crystal is removed, the residual solution on the surface is blown away with a nitrogen gun, and then annealed in an oven and gradually cooled to room temperature, thereby obtaining MAPbBr3 (Bi) as the N layer on the surface of the PI layer crystal (001). 3+ Single-crystal homojunction, i.e., PIN three-layer crystal;

[0042] 7) Polish the PIN three-layer crystal obtained in step 6) with DMF polishing slurry containing diamond powder, and grind away the excess crystal at the edge to a regular cube with the same size as the CsPbBr3 single crystal substrate to form an asymmetric PIN perovskite crystal.

[0043] 8) The N-layer MAPbBr3(Bi) of the asymmetric PIN perovskite crystal obtained in step 7) 3+ A Cr electrode is prepared on the upper surface of the N-layer (doped) and the lower surface of the P-layer CsPbBr3 (the area of ​​the Cr electrode on the N-layer surface is 3mm*3mm and the electrode thickness is 100nm; the area of ​​the Cr electrode on the P-layer surface is 0.1mm*0.1mm and the electrode thickness is 100nm), thereby obtaining the dual-mode asymmetric PIN perovskite radiation detector.

[0044] The above embodiments are merely illustrative examples of the technical solutions of the present invention. The perovskite unipolar barrier photodetector and its fabrication method involved in this invention are not limited to the content described in the above embodiments, but are defined by the scope of the claims. Any modifications, supplements, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. A method for fabricating a dual-mode asymmetric PIN perovskite radiation detector, comprising the following steps: 1) Weigh CsBr and PbBr2 powders with a molar ratio of 1:2, dissolve them in DMSO solution, stir at 40~60℃ for 12~15h until the powder is completely dissolved, let stand and remove the precipitate to obtain a clear CsPbBr3 solution, i.e. perovskite single crystal precursor solution. 2) A small amount of the precursor solution obtained in step 1) is drawn out with a syringe and seeded crystals are grown in the small amount of solution at a constant temperature. Then, a seed crystal with good shape, no cracks and transparent is selected and placed in a crystal growth bottle containing the remaining perovskite single crystal precursor solution. The bottle cap is loosened to allow the solvent to evaporate slowly until a CsPbBr3 single crystal with a thickness of 2~4mm is grown. The crystal is taken out, dried with a nitrogen gun, and annealed in an oven and gradually cooled to room temperature to obtain a CsPbBr3 single crystal as a P-type substrate. 3) Take out the grown CsPbBr3 single crystal, blow off the residual solution on its surface with a nitrogen gun, and polish the surface of the CsPbBr3 single crystal with DMSO polishing liquid containing diamond powder to smooth the bottom surface that has pitted due to the container during natural growth; then, take an appropriate amount of PDMS encapsulating adhesive into the crystal growth bottle, immerse the lower half of the CsPbBr3 single crystal in PDMS, and place the crystal growth bottle on a hot stage at 70~80℃ for 10~20min to solidify the encapsulating adhesive to isolate the heterojunction growth solution; 4) Weigh MABr and PbBr2 powders with a molar ratio of 1:1, dissolve them in DMF solution, stir at room temperature for 12-15 hours until the powder is completely dissolved, remove the precipitate after standing to obtain a clear MAPbBr3 solution; then inject it into the crystal growth bottle of step 3), and grow MAPbBr3 single crystal heterojunction at a constant temperature with the cap of the crystal growth bottle loosened; when the thickness of the in-situ grown MAPbBr3 single crystal heterojunction is 1.5-3.0 mm, take out the crystal, blow off the residual solution on the surface with a nitrogen gun, and anneal in an oven to gradually cool to room temperature, thereby growing a MAPbBr3 single crystal heterojunction as the I layer, i.e., the PI layer crystal, on the (001) crystal surface of the CsPbBr3 single crystal as the P-type substrate; 5) Polish the PI layer crystal obtained in step 4) with DMF polishing slurry containing diamond powder to remove excess crystals at the edges of the MAPbBr3 single crystal heterolayer that are epitaxially grown around the crystal until a regular cube of the same size as the CsPbBr3 single crystal substrate is formed; then, take an appropriate amount of PDMS encapsulant into the crystal growth bottle, place the MAPbBr3 crystal with the darker color of the PI layer crystal facing upwards, and immerse the lower half of the PI layer single crystal in PDMS. Place the crystal growth bottle on a hot plate and heat at 70~80℃ for 10~20 minutes to solidify the encapsulant to isolate the heterojunction growth solution; 6) Weigh MABr and PbBr2 powders in a molar ratio of 1:1, and BiBr3 powder at 0.01% molar amount of PbBr2. Dissolve them in DMF (N,N-dimethylformamide) solution and stir magnetically at room temperature for 12-15 hours until the powders are completely dissolved to obtain clear MABr3 (BiBr2). 3+ The doped solution was then injected into the crystal growth flask in step 5), and homojunction interface growth was carried out at a constant temperature with the cap loosened; when the in-situ grown MAPbBr3 (Bi 3+ When the thickness of the doped homojunction is 45~55μm, the crystal is removed, the residual solution on the surface is blown off with a nitrogen gun, and then annealed in an oven and gradually cooled to room temperature, thereby obtaining MAPbBr3 (Bi) as the N layer on the (001) crystal plane of the PI layer crystal. 3+ Doped single-crystal homojunction, i.e., PIN three-layer crystal; 7) Polish the PIN three-layer crystal obtained in step 6) with DMF polishing slurry containing diamond powder, and grind away the excess single crystal at the edge to a regular cube with the same size as the CsPbBr3 single crystal substrate to form an asymmetric PIN perovskite crystal. 8) The N-layer MAPbBr3(Bi) of the asymmetric PIN perovskite crystal obtained in step 7) 3+ A Cr electrode is prepared on the doped upper surface and the P-layer CsPbBr3 lower surface to obtain the dual-mode asymmetric PIN perovskite radiation detector.

2. The method for fabricating a dual-mode asymmetric PIN perovskite radiation detector as described in claim 1, characterized in that: In step 2), the isothermal temperature for seed crystal growth is 75~80℃, and the growth time is 2~3h; the isothermal temperature for growing CsPbBr3 single crystal is 75~80℃, and the growth time is 4~6 days.

3. The method for fabricating a dual-mode asymmetric PIN perovskite radiation detector as described in claim 1, characterized in that: In step 4), the isothermal temperature for heterojunction interface growth is 55~65℃.

4. The method for fabricating a dual-mode asymmetric PIN perovskite radiation detector as described in claim 1, characterized in that: In step 6), the isothermal temperature for the growth of the homojunction interface is 55~65℃.

5. A dual-mode asymmetric PIN perovskite radiation detector, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 4.

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