A TEA2PbI4 perovskite single crystal, a preparation method and application thereof

Abstract

This invention relates to the field of perovskite single crystal materials, specifically to a TEA2PbI4 perovskite single crystal, its preparation method, and its applications. The preparation method includes a slow-cooling solution growth method, controlling the crystallization conditions to obtain TEA2PbI4 perovskite single crystals with high crystal quality and high carrier mobility. Based on this, the surface of the single crystal is modified by tungsten (W) ion implantation to enhance its photoelectric properties. The modified single crystal is used to fabricate an X-ray detector, which exhibits high sensitivity, low detection limit, and excellent signal-to-noise ratio characteristics in X-ray detection.

Description

Technical Field

[0001] This invention relates to the field of perovskite single crystal material technology, specifically to a TEA2PbI4 perovskite single crystal, its preparation method, and its application. Background Technology

[0002] X-ray detection technology plays a crucial role in medical diagnosis, industrial non-destructive testing, and security inspection, with the demand for medical X-ray detectors in medical diagnosis growing rapidly. Perovskite materials, due to their excellent carrier transport properties and high effective atomic number, are the preferred materials for high-energy radiation detection. However, the poor stability, numerous defects, and low carrier mobility of polycrystalline perovskite films limit their practical application in photodetectors. In contrast, single-crystal perovskite exhibits superior photoelectric properties; its high atomic number, high resistivity, and long carrier migration lifetime result in a higher radiation attenuation coefficient and carrier collection efficiency, making it more suitable for X-ray detectors.

[0003] Three-dimensional (3D) perovskite materials are prone to spontaneous phase transitions at room temperature and are unstable in humid environments, limiting their application in atmospheric environments. In contrast, two-dimensional (2D) thiophene-based perovskite materials, through the separation of the inorganic framework by organic cations, significantly suppress ion migration and improve environmental stability. Simultaneously, the rigid structure of the thiophene ring and the coordination ability of sulfur atoms enhance interlayer interactions and reduce defect state density. Furthermore, ion implantation technology enables high-purity doping, precisely controlling ion concentration and depth distribution, avoiding potential damage to single crystals caused by solvent engineering and interface engineering, thereby increasing the intrinsic carrier concentration of the single crystal and significantly enhancing the photoelectric properties of perovskite materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a TEA2PbI4 perovskite single crystal, its preparation method, and its applications. A perovskite single crystal material with high crystallinity and high carrier mobility is obtained through a slow-cooling solution growth method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing TEA2PbI4 perovskite single crystals includes the following preparation steps:

[0007] S1. Mix 2-thiophene ethylamine with hydroiodic acid and stir until homogeneous to obtain a first solution containing 2-thiophene ethylamine and hydroiodic acid; add lead oxide powder to the mixed solution of hydroiodic acid and hypophosphorous acid and stir until dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid.

[0008] S2. Mix the first solution and the second solution from step S1, and stir to obtain a pale yellow mixture containing a small amount of precipitate;

[0009] S3. Add anhydrous ethanol to the pale yellow mixture in step S2 and stir until the precipitate is completely dissolved to obtain a pale yellow clear precursor solution;

[0010] S4. Place the precursor solution from step S3 in an oil bath container, which is pre-placed on a hot plate and its temperature is kept consistent with the temperature of the hot plate; then heat the oil bath container to 80-85°C and keep it at that temperature for a predetermined time, and then slowly cool it to room temperature in two stages to obtain orange-yellow blocky TEA2PbI4 perovskite single crystals.

[0011] S5. The perovskite single crystal is cleaned and dried multiple times, and then its surface is polished to obtain a bright thiophene-based lead iodide perovskite TEA2PbI4 single crystal.

[0012] In step S1, the volume ratio of 2-thiopheneethylamine to hydroiodic acid solution in the first solution is 1:2-4.

[0013] In the second solution of step S1, the volume ratio of hydroiodic acid to hypophosphoric acid is 4-6:1.

[0014] Preferably, the stirring operations in steps S1, S2 and S3 are all carried out at a temperature of 50-70°C, and the stirring time in steps S1 and S2 is 60-180 minutes.

[0015] Preferably, in step S1, the ratio of the hydroiodic acid and hypophosphite mixed solution to lead oxide in the second solution is: 2-3 mmol of lead oxide is added for every 3-6 mL of mixed solution.

[0016] Preferably, in step S3, the volume ratio of anhydrous ethanol to the pale yellow mixture is 1:3-6.

[0017] Preferably, in step S4, the heating rate to 80-85℃ is 5℃ / h, and the holding time is 60-120 minutes; the cooling process is divided into two stages: the first stage cools down to 50℃ at a cooling rate of 1-3℃ / h; the second stage cools down from 50℃ to 25℃ at a cooling rate of 0.2-0.4℃ / h.

[0018] Preferably, in step S5, the obtained perovskite single crystal is cleaned 3-5 times with toluene or chlorobenzene; the drying temperature is 30-50℃ and the drying time is 2 hours; the polishing treatment uses 12000-grit fine sandpaper to polish the surface of the single crystal.

[0019] A TEA2PbI4 perovskite single crystal was prepared by the above-described preparation method.

[0020] An application of a TEA2PbI4 perovskite single crystal in ion implantation and its detector includes the following steps:

[0021] S11. The bright thiophene-based lead iodide perovskite TEA2PbI4 single crystal prepared in step S5 is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface.

[0022] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 4 × 10⁻⁶. 15 ions / cm 2 Up to 2×10 17 ions / cm 2 We obtained W-modified TEA2PbI4 perovskite single crystals.

[0023] S13. The single crystal after ion implantation undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 80-120 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention utilizes a controlled-temperature solution growth method to successfully prepare high-performance TEA2PbI4 perovskite single crystals. These crystals exhibit excellent environmental stability, maintaining structural integrity and stable performance even under harsh environmental conditions. They also possess superior optical properties, combining a suitable optical bandgap with strong light absorption. Furthermore, this method is simple, low-cost, and allows for flexible experimental conditions, demonstrating good scalability and application prospects.

[0026] 2. This invention employs ion implantation technology to modify TEA2PbI4 perovskite single crystals and successfully applies it to X-ray detectors. By implanting W ions, the electrical properties of the material are effectively modulated, increasing the intrinsic carrier concentration and thus significantly enhancing the overall performance of the X-ray detector. This method not only greatly improves the detector's response speed and long-term operational stability but also effectively suppresses dark current, thereby improving detection sensitivity and the minimum detection limit. Attached Figure Description

[0027] Figure 1 This is a process flow diagram for preparing TEA2PbI4 perovskite single crystals according to the present invention.

[0028] Figure 2 This is a single crystal structure diagram of the TEA2PbI4 perovskite single crystal of the present invention;

[0029] Figure 3This is a photograph of the TEA2PbI4 perovskite single crystal of the present invention;

[0030] Figure 4 The XRD diffraction patterns of TEA2PbI4 perovskite single crystal, powder, and theoretically simulated XRD patterns prepared in Example 1 of this invention are shown.

[0031] Figure 5 The photoluminescence spectra of a TEA2PbI4 perovskite single crystal before and after ion implantation in Example 1 of this invention;

[0032] Figure 6 The image shows the IV diagrams in the dark state of the TEA2PbI4 perovskite single crystal X-ray detector and the TEA2PbI4 perovskite single crystal X-ray detector prepared by ion implantation in Example 1 of the present invention.

[0033] Figure 7 In Example 1 of this invention, the TEA2PbI4 perovskite single-crystal X-ray detector was exposed to 10.7 μGy before and after W ion implantation. air ·s -1 Comparison of X-ray response current stability at a dose rate and a bias voltage of 50V;

[0034] Figure 8 This is a comparison chart of the detection sensitivity of the TEA2PbI4 perovskite single crystal X-ray detector before and after W ion implantation in Example 1 of the present invention. Detailed Implementation

[0035] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] Please see Figure 1-8 The present invention provides a technical solution:

[0037] TEA2PbI4 perovskite is a 2D perovskite with an RP phase structure and the general structural formula (C4H3SC2H4(NH3))2PbI4. It belongs to the monoclinic crystal system with space group Cc, and its lattice parameters are a = 12.284 Å, b = 12.325 Å, c = 31.381 Å, α = γ = 90°, β = 90.972°. The single-crystal structure of (C4H3SC2H4(NH3))2PbI4 is shown in the attached figure. Figure 2 As shown, the inorganic layer is composed of Pb 2+ With 6 I - [PbI6] with coordination structure 2-Octahedrons connected by common vertices extend infinitely in space to form a structure, while monoamine TEA... + Then with the inorganic layer I - They interact through hydrogen bonds.

[0038] Example 1

[0039] This embodiment provides a method for preparing TEA2PbI4 perovskite single crystals, which is implemented according to the following steps:

[0040] S1. Mix 2-thiopheneethylamine and hydroiodic acid solution at a volume ratio of 1:2 and stir at 50°C for 60 minutes to obtain a first solution containing 2-thiopheneethylamine and hydroiodic acid; add lead oxide powder to a mixed solution of hydroiodic acid and hypophosphorous acid at a volume ratio of 4:1 and stir at 50°C for 60 minutes until completely dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid; wherein, the feeding ratio of the mixed solution of hydroiodic acid and hypophosphorous acid to lead oxide is 2 mmol of lead oxide for every 3 mL of the mixed solution;

[0041] S2. Mix the first solution and the second solution from step S1 at 50°C and stir for 60 minutes to obtain a pale yellow mixture containing a small amount of precipitate;

[0042] S3. Add anhydrous ethanol to the pale yellow mixture obtained in step S2, with a volume ratio of anhydrous ethanol to pale yellow mixture of 1:3. Stir at 60°C until the precipitate is completely dissolved to obtain a pale yellow and clear precursor solution.

[0043] S4. The precursor solution obtained in step S3 is transferred to an oil bath container, which is pre-placed on a hot plate and kept at the same initial temperature as the stirring and dissolving stage; then the oil bath container is heated to 85°C at a rate of 5°C / h and held at this temperature for 60 minutes; then it is slowly cooled to room temperature in two stages: the first stage is from 85°C to 50°C at a cooling rate of 1°C / h; the second stage is from 50°C to 25°C at a cooling rate of 0.2°C / h, finally obtaining orange-yellow blocky TEA2PbI4 perovskite single crystals;

[0044] S5. The obtained perovskite single crystal was cleaned three times with toluene, then dried at 30°C for 2 hours, and then its surface was polished with 12000-grit sandpaper to obtain a bright TEA2PbI4 thiophene-based lead iodide perovskite single crystal.

[0045] Example 2

[0046] This embodiment provides a method for preparing TEA2PbI4 perovskite single crystals, which is implemented according to the following steps:

[0047] S1. Mix 2-thiopheneethylamine and hydroiodic acid solution at a volume ratio of 1:3 and stir at 50°C for 90 minutes to obtain a first solution containing 2-thiopheneethylamine and hydroiodic acid; add lead oxide powder to a mixed solution of hydroiodic acid and hypophosphorous acid at a volume ratio of 4:1 and stir at 50°C for 100 minutes until completely dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid; wherein, the feeding ratio of the mixed solution of hydroiodic acid and hypophosphorous acid to lead oxide is 2 mmol of lead oxide for every 3 mL of the mixed solution;

[0048] S2. Mix the first solution and the second solution from step S1 at 50°C and stir for 90 minutes to obtain a pale yellow mixture containing a small amount of precipitate;

[0049] S3. Add anhydrous ethanol to the pale yellow mixture obtained in step S2. The volume ratio of anhydrous ethanol to the pale yellow mixture is 1:4. Stir at 50°C until the precipitate is completely dissolved to obtain a pale yellow and clear precursor solution.

[0050] S4. The precursor solution obtained in step S3 is transferred to an oil bath container, which is pre-placed on a hot plate and kept at the same initial temperature as the stirring and dissolving stage; then the oil bath container is heated to 85°C at a rate of 5°C / h and held at this temperature for 60 minutes; then it is slowly cooled to room temperature in two stages: the first stage is from 85°C to 50°C at a cooling rate of 1.5°C / h; the second stage is from 50°C to 25°C at a cooling rate of 0.2°C / h, finally obtaining orange-yellow blocky TEA2PbI4 perovskite single crystals;

[0051] S5. The obtained perovskite single crystal was cleaned three times with toluene, then dried at 30°C for 2 hours, and then its surface was polished with 12000-grit sandpaper to obtain a bright TEA2PbI4 thiophene-based lead iodide perovskite single crystal.

[0052] Example 3

[0053] This embodiment provides a method for preparing TEA2PbI4 perovskite single crystals, which is implemented according to the following steps:

[0054] S1. Mix 2-thiopheneethylamine and hydroiodic acid solution at a volume ratio of 1:4 and stir at 60°C for 150 minutes to obtain a first solution containing 2-thiopheneethylamine and hydroiodic acid; add lead oxide powder to a mixed solution of hydroiodic acid and hypophosphorous acid at a volume ratio of 4:1 and stir at 60°C for 120 minutes until completely dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid; wherein, the feeding ratio of the mixed solution of hydroiodic acid and hypophosphorous acid to lead oxide is 2 mmol of lead oxide for every 3 mL of the mixed solution;

[0055] S2. Mix the first solution and the second solution from step S1 at 60°C and stir for 150 minutes to obtain a pale yellow mixture containing a small amount of precipitate;

[0056] S3. Add anhydrous ethanol to the pale yellow mixture obtained in step S2, with a volume ratio of anhydrous ethanol to pale yellow mixture of 1:5, and stir at 70°C until the precipitate is completely dissolved to obtain a pale yellow and clear precursor solution.

[0057] S4. The precursor solution obtained in step S3 is transferred to an oil bath container, which is pre-placed on a hot plate and kept at the same initial temperature as the stirring and dissolving stage; then the oil bath container is heated to 85°C at a rate of 5°C / h and held at this temperature for 90 minutes; then it is slowly cooled to room temperature in two stages: the first stage is from 85°C to 50°C at a cooling rate of 2°C / h; the second stage is from 50°C to 25°C at a cooling rate of 0.3°C / h, finally obtaining orange-yellow blocky TEA2PbI4 perovskite single crystals;

[0058] S5. The obtained perovskite single crystal was cleaned three times with toluene, then dried at 30°C for 2 hours, and then its surface was polished with 12000-grit sandpaper to obtain a bright TEA2PbI4 thiophene-based lead iodide perovskite single crystal.

[0059] Example 4

[0060] This embodiment provides a method for preparing TEA2PbI4 perovskite single crystals, which is implemented according to the following steps:

[0061] S1. Mix 2-thiopheneethylamine and hydroiodic acid solution at a volume ratio of 1:2 and stir at 60°C for 180 minutes to obtain a first solution containing 2-thiopheneethylamine and hydroiodic acid; add lead oxide powder to a mixed solution of hydroiodic acid and hypophosphorous acid at a volume ratio of 5:1 and stir at 70°C for 120 minutes until completely dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid; wherein, the feeding ratio of the mixed solution of hydroiodic acid and hypophosphorous acid to lead oxide is 3 mmol of lead oxide for every 4 mL of the mixed solution;

[0062] S2. Mix the first solution and the second solution from step S1 at 70°C and stir for 120 minutes to obtain a pale yellow mixture containing a small amount of precipitate;

[0063] S3. Add anhydrous ethanol to the pale yellow mixture obtained in step S2, with a volume ratio of anhydrous ethanol to pale yellow mixture of 1:3, and stir at 70°C until the precipitate is completely dissolved to obtain a pale yellow and clear precursor solution.

[0064] S4. The precursor solution obtained in step S3 is transferred to an oil bath container, which is pre-placed on a hot table and kept at the same initial temperature as the stirring and dissolving stage; then the oil bath container is heated to 80°C at a rate of 5°C / h and held at this temperature for 120 minutes; then it is slowly cooled to room temperature in two stages: the first stage is from 80°C to 50°C at a cooling rate of 3°C / h; the second stage is from 50°C to 25°C at a cooling rate of 0.4°C / h, finally obtaining orange-yellow blocky TEA2PbI4 perovskite single crystals;

[0065] S5. The obtained perovskite single crystal was cleaned 5 times with chlorobenzene, then dried at 40°C for 2 hours, and then polished with 12000-grit sandpaper to obtain a bright TEA2PbI4 thiophene-based lead iodide perovskite single crystal.

[0066] Example 5

[0067] This embodiment provides a method for preparing TEA2PbI4 perovskite single crystals, which is implemented according to the following steps:

[0068] S1. Mix 2-thiopheneethylamine and hydroiodic acid solution at a volume ratio of 1:3 and stir at 70°C for 120 minutes to obtain a first solution containing 2-thiopheneethylamine and hydroiodic acid; add lead oxide powder to a mixed solution of hydroiodic acid and hypophosphorous acid at a volume ratio of 6:1 and stir at 60°C for 180 minutes until completely dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid; wherein, the feeding ratio of the mixed solution of hydroiodic acid and hypophosphorous acid to lead oxide is 2.5 mmol of lead oxide for every 6 mL of the mixed solution;

[0069] S2. Mix the first solution and the second solution from step S1 at 60°C and stir for 180 minutes to obtain a pale yellow mixture containing a small amount of precipitate;

[0070] S3. Add anhydrous ethanol to the pale yellow mixture obtained in step S2, with a volume ratio of anhydrous ethanol to pale yellow mixture of 1:6, and stir at 60°C until the precipitate is completely dissolved to obtain a pale yellow and clear precursor solution.

[0071] S4. The precursor solution obtained in step S3 is transferred to an oil bath container, which is pre-placed on a hot plate and kept at the same initial temperature as the stirring and dissolving stage; then the oil bath container is heated to 83°C at a rate of 5°C / h and held at this temperature for 90 minutes; then it is slowly cooled to room temperature in two stages: the first stage is from 83°C to 50°C at a cooling rate of 2°C / h; the second stage is from 50°C to 25°C at a cooling rate of 0.4°C / h, finally obtaining orange-yellow blocky TEA2PbI4 perovskite single crystals;

[0072] S5. The obtained perovskite single crystal was cleaned four times with chlorobenzene, then dried at 50°C for 2 hours, and then its surface was polished with 12000-grit sandpaper to obtain a bright TEA2PbI4 thiophene-based lead iodide perovskite single crystal.

[0073] Application Example 1

[0074] This embodiment provides an ion implantation modification method for TEA2PbI4 perovskite single crystals and its application in X-ray detectors. The modification and application are based on the TEA2PbI4 perovskite single crystals prepared in Example 1, and are implemented according to the following steps:

[0075] S11. The prepared orange-yellow blocky TEA2PbI4 perovskite single crystal is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface;

[0076] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 4 × 10⁻⁶. 15 ions / cm², to obtain W-modified TEA2PbI4 perovskite single crystals;

[0077] S13. The ion-implanted single crystal undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 80 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0078] Application Example 2

[0079] This embodiment provides an ion implantation modification method for TEA2PbI4 perovskite single crystals and its application in X-ray detectors. The modification and application are based on the TEA2PbI4 perovskite single crystals prepared in Example 2, and are implemented according to the following steps:

[0080] S11. The prepared orange-yellow blocky TEA2PbI4 perovskite single crystal is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface;

[0081] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 5 × 10⁻⁶. 15 ions / cm², to obtain W-modified TEA2PbI4 perovskite single crystals;

[0082] S13. The ion-implanted single crystal undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 90 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0083] Application Example 3

[0084] This embodiment provides an ion implantation modification method for TEA2PbI4 perovskite single crystals and its application in X-ray detectors. The modification and application are based on the TEA2PbI4 perovskite single crystals prepared in Example 3, and are implemented according to the following steps:

[0085] S11. The prepared orange-yellow blocky TEA2PbI4 perovskite single crystal is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface;

[0086] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 5 × 10⁻⁶. 16 ions / cm², to obtain W-modified TEA2PbI4 perovskite single crystals;

[0087] S13. The ion-implanted single crystal undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 100 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0088] Application Example 4

[0089] This embodiment provides an ion implantation modification method for TEA2PbI4 perovskite single crystals and its application in X-ray detectors. The modification and application are based on the TEA2PbI4 perovskite single crystals prepared in Example 4, and are implemented according to the following steps:

[0090] S11. The prepared orange-yellow blocky TEA2PbI4 perovskite single crystal is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface;

[0091] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 2×10⁻⁶. 17 ions / cm², to obtain W-modified TEA2PbI4 perovskite single crystals;

[0092] S13. The ion-implanted single crystal undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 120 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0093] Application Example 5

[0094] This embodiment provides an ion implantation modification method for TEA2PbI4 perovskite single crystals and its application in X-ray detectors. The modification and application are based on the TEA2PbI4 perovskite single crystals prepared in Example 5, and are implemented according to the following steps:

[0095] S11. The prepared orange-yellow blocky TEA2PbI4 perovskite single crystal is subjected to surface polishing treatment to obtain a single crystal material with a smooth surface;

[0096] S12. Perform W element ion implantation on the polished single crystal surface, with an implantation dose range of 2×10⁻⁶. 16 ions / cm², to obtain W-modified TEA2PbI4 perovskite single crystals;

[0097] S13. The ion-implanted single crystal undergoes surface cleaning and secondary polishing. Subsequently, gold electrodes are deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes is 100 nm, and the area of ​​a single electrode is 20 mm². 2 .

[0098] Performance testing:

[0099] Appendix Figure 3 The image shows a photograph of the TEA2PbI4 perovskite single crystal of this invention. As can be seen from the photograph, the size of the TEA2PbI4 perovskite single crystal of this invention is 2 mm × 10 mm.

[0100] Appendix Figure 4 The figures show the XRD diffraction patterns of the TEA2PbI4 perovskite single crystal and powder prepared in Example 1 of this invention, and the theoretical simulation results. The figures show that the XRD diffraction peak positions of the prepared TEA2PbI4 perovskite single crystal and powder are consistent with the theoretical simulation results, indicating that the obtained product is indeed the TEA2PbI4 perovskite material with the target structure. The single crystal sample has sharp diffraction peaks and no obvious impurity peaks, indicating high crystallinity, good phase purity, and the absence of significant impurities or a second phase.

[0101] Appendix Figure 5 The images show the photoluminescence spectra of TEA2PbI4 perovskite single crystals before and after ion implantation in Example 1 of this invention. The TEA2PbI4 perovskite single crystal implanted with W ions exhibits a significant PL emission peak at 522 nm, with a significantly higher intensity than the unimplanted sample. This phenomenon indicates that W ion implantation effectively improves the carrier recombination efficiency of the material.

[0102] Appendix Figure 6The image shows the dark-state IV diagrams of a TEA2PbI4 perovskite single-crystal X-ray detector and a TEA2PbI4 perovskite single-crystal X-ray detector prepared by ion implantation in Example 1 of this invention. After ion implantation, the dark current of the TEA2PbI4 perovskite single-crystal X-ray detector is significantly reduced, indicating that ion implantation introduces deep-level defects or increases the resistivity of the material, effectively suppressing the generation of thermally excited charge carriers. This improvement effectively enhances its detection performance.

[0103] Appendix Figure 7 In Example 1 of this invention, the TEA2PbI4 perovskite single-crystal X-ray detector was exposed to 10.7 μGy before and after W ion implantation. air ·s -1 A comparison of X-ray response current stability at a dose rate and a bias voltage of 50V is shown in the figure. As can be seen from the figure, after ion implantation, the TEA2PbI4 perovskite single-crystal X-ray detector exhibits highly repeatable response characteristics in multiple switching cycle tests, demonstrating the device's excellent operational stability.

[0104] Appendix Figure 8 This is a comparison of the detection sensitivity of the TEA2PbI4 perovskite single-crystal X-ray detector before and after ion implantation in Application Example 1 of this invention. After ion implantation, the detection sensitivity of the TEA2PbI4 perovskite single-crystal X-ray detector under the same conditions is higher than that of the unimplanted TEA2PbI4 perovskite single-crystal X-ray detector, indicating that ion implantation of the single crystal enhances its detection sensitivity.

[0105] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a TEA2PbI4 perovskite single crystal, characterized in that, The preparation steps include the following: S1. Mix 2-thiophene ethylamine with hydroiodic acid and stir until homogeneous to obtain a first solution containing 2-thiophene ethylamine and hydroiodic acid; add lead oxide powder to the mixed solution of hydroiodic acid and hypophosphorous acid and stir until dissolved to obtain a second solution containing lead oxide, hydroiodic acid and hypophosphorous acid. S2. Mix the first solution and the second solution from step S1, and stir to obtain a pale yellow mixture containing a small amount of precipitate; S3. Add anhydrous ethanol to the pale yellow mixture in step S2 and stir until the precipitate is completely dissolved to obtain a pale yellow clear precursor solution; S4. Place the precursor solution from step S3 in an oil bath container, which is pre-placed on a hot plate and its temperature is kept consistent with the temperature of the hot plate; then heat the oil bath container to 80-85°C and keep it at that temperature for a predetermined time, and then slowly cool it to room temperature in two stages to obtain orange-yellow blocky TEA2PbI4 perovskite single crystals. S5. The perovskite single crystal is repeatedly cleaned and dried, and then its surface is polished to obtain a bright thiophene-based lead iodide perovskite (TEA2PbI4) single crystal. The prepared bright thiophene-based lead iodide perovskite (TEA2PbI4) single crystal is then further polished to obtain a single crystal material with a smooth surface. W element ion implantation is then performed on the polished single crystal surface, with an implantation dose range of 4 × 10⁻⁶. 15 ions / cm 2 Up to 2×10 17 ions / cm 2 We obtained W-modified TEA2PbI4 perovskite single crystals. In step S1, the volume ratio of 2-thiopheneethylamine to hydroiodic acid solution in the first solution is 1:2-4. In the second solution of step S1, the volume ratio of hydroiodic acid to hypophosphoric acid is 4-6:

1.

2. The method of claim 1, wherein the TEA2PbI4 perovskite single crystal is prepared by the method, characterized in that, The stirring operations in steps S1, S2 and S3 are all carried out at a temperature of 50-70℃, and the stirring time in steps S1 and S2 is 60-180 minutes.

3. The method for preparing a TEA2PbI4 perovskite single crystal according to claim 1, characterized in that, In step S1, the ratio of the hydroiodic acid and hypophosphite mixed solution to lead oxide in the second solution is: 2-3 mmol of lead oxide is added for every 3-6 mL of mixed solution.

4. The method of claim 1, wherein the TEA2PbI4 perovskite single crystal is prepared by the method, characterized in that, In step S3, the volume ratio of anhydrous ethanol to the pale yellow mixture is 1:3-6.

5. The method for preparing a TEA2PbI4 perovskite single crystal according to claim 1, characterized in that, In step S4, the heating rate to 80-85℃ is 5℃ / h, and the holding time is 60-120 minutes; the cooling process is divided into two stages: the first stage is cooling down to 50℃ at a cooling rate of 1-3℃ / h; the second stage is cooling down from 50℃ to 25℃ at a cooling rate of 0.2-0.4℃ / h.

6. The method of claim 1, wherein the TEA2PbI4 perovskite single crystal is prepared by the method, characterized in that, In step S5, the obtained perovskite single crystal is cleaned 3-5 times with toluene or chlorobenzene; the drying temperature is 30-50℃ and the drying time is 2 hours; the polishing treatment uses 12000-grit fine sandpaper to polish the surface of the single crystal.

7. A TEA2Pbl4 perovskite single crystal, characterized in that, It is prepared by the preparation method described in any one of claims 1-6.

8. The application of a TEA2PbI4 perovskite single crystal in a detector according to claim 7.

9. Use according to claim 8, characterized in that, The application includes the following steps: The ion-implanted single crystal underwent surface cleaning and secondary polishing. Subsequently, gold electrodes were deposited on both the front and back surfaces of the material to form a vertically structured perovskite X-ray detector. The thickness of the deposited gold electrodes was 80-120 nm, and the area of ​​a single electrode was 20 mm². 2 .

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