A large-area metal halide thick film for X-ray detection, its preparation method and application

Abstract

This invention belongs to the field of scintillator material technology. It discloses a large-area metal halide thick film for X-ray detection, its preparation method, and its application. The preparation method includes the following steps: (1) mixing A-site ion halide, B-site ion halide, and solvent to obtain solution a; (2) mixing solution a with a polymer to obtain solution b; (3) coating solution b onto a substrate and annealing to obtain a large-area metal halide thick film. The method described in this invention enables large-area, low-temperature, in-situ growth of nanocrystals of different metal halides. This prevents light scattering and uneven distribution of the nanocrystals while providing sufficient film thickness to absorb X-rays, thus achieving a high-quality, non-agglomerated large-area metal halide thick film. Furthermore, the large-area metal halide thick film prepared by this process also possesses high transparency, is not easily broken, and exhibits excellent environmental stability, better meeting market demands for scintillator materials.

Description

Technical Field

[0001] This invention relates to the field of scintillator materials technology, and in particular to a large-area metal halide thick film for X-ray detection, its preparation method and application. Background Technology

[0002] Scintillator materials, capable of converting ionizing radiation into visible or ultraviolet light, are widely used in various fields such as interstellar particle detection, security inspection, and nuclear cameras. However, the preparation temperatures of commercially available traditional scintillator CsI crystals and cerium-activated glasses are relatively high, which severely hinders the development of scintillator materials in integration and large-area fabrication.

[0003] Research indicates that solution-based methods are one of the most promising approaches to achieving controllable scintillator area and thickness. Among these, organic dye solutions (such as C...) 18 H 14 C 20 H 14 N 20 C 15 H 11 NO has been used as a scintillator material in neutron detection. However, due to the low atomic number of its internal components, its absorption capacity for high-energy particles is weak, resulting in poor detection performance. Furthermore, organic dye solutions are inherently susceptible to photobleaching and oxygen quenching, significantly limiting the application scenarios and scope of detection. In recent years, metal halides, due to their inclusion of heavy metal ions, have become the best candidate materials for X-ray detection. Among them, single-crystal metal halides have gained favor among researchers due to their low trap density, strong X-ray absorption capacity, and excellent environmental stability. However, the complex and expensive single-crystal growth process makes achieving area-tunable fabrication challenging, inhibiting their application in large-scale detection. Therefore, how to fabricate large-area metal halides using a simple and low-cost method is currently key to the development of X-ray detection. Summary of the Invention

[0004] The purpose of this invention is to provide a large-area metal halide thick film for X-ray detection, its preparation method and application, in order to solve the problems that existing methods for preparing metal halide films cannot achieve controllability of film thickness and area, and that the preparation process is complex and costly.

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

[0006] This invention provides a method for preparing a large-area metal halide thick film for X-ray detection, comprising the following steps:

[0007] (1) Mix the A-site ion halide, the B-site ion halide and the solvent to obtain solution a;

[0008] (2) Mix solution a with the polymer to obtain solution b;

[0009] (3) The solution b is coated on the substrate and then annealed at low temperature to obtain a large area metal halide thick film;

[0010] The A-site ion halide is one or more of benzyltriphenylphosphine halide and cesium halide; the B-site ion halide is one or more of manganese halide, cuprous halide, and lead halide.

[0011] Preferably, in step (1), the solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, water, methanol, toluene, acetonitrile, acetic acid, hydrobromic acid, hydroiodic acid, hydrochloric acid, nitric acid, and hypophosphoric acid; in solution a, the concentration of the A-site ion halide is 0.1–2 mmol / mL; and the concentration of the B-site ion halide is 0.1–1 mmol / L.

[0012] Preferably, in step (2), the polymer is one or more of polyvinylpyrrolidone, polyvinyl alcohol, polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene chloride, polylactic acid, polyethylene glycol, polybutyl acrylate, and polyimide; and the concentration of the polymer in solution b is 50-200 mg / mL.

[0013] Preferably, in steps (1) and (2), the mixing temperature is 40-80°C and the mixing time is 6-8h.

[0014] Preferably, in step (3), the substrate is a glass plate.

[0015] Preferably, in step (3), the coating thickness is 300-600 μm and the coating speed is 1-5 mm / s.

[0016] Preferably, in step (3), the temperature of the low-temperature annealing is 60 to 140°C, and the time of the low-temperature annealing is 0.5 to 4 hours.

[0017] The present invention also provides a method for preparing a large-area metal halide thick film for X-ray detection.

[0018] The present invention also provides the application of the large-area metal halide thick film in X-ray imaging or radiation protection.

[0019] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) The large-area metal halide thick film obtained by the present invention has high crystallinity, excellent mechanical strength and stability, and the transparency of the film layer is significantly improved, which is beneficial to the improvement of the final X-ray imaging resolution.

[0021] (2) The low-temperature preparation method of large-area metal halide thick film described in this invention can effectively prevent high-temperature damage to external integrated circuit boards or coupled photodetectors;

[0022] (3) The large-area metal halide thick film of the present invention has the advantages of strong universality, good uniformity, easy industrial preparation, simple manufacturing process and low cost; and has detection performance far superior to commercial bismuth germanate (BGO) crystal and other materials. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 The images show actual images of the large-area metal halide thick film obtained in Example 1 under visible light and X-ray irradiation. The left image is the actual image under visible light, and the right image is the actual image under X-ray irradiation.

[0025] Figure 2 The images shown are actual images of the large-area metal halide thick film obtained in Example 2 under visible light and X-ray irradiation. The left image is the actual image under visible light, and the right image is the actual image under X-ray irradiation.

[0026] Figure 3 The images shown are actual images of the large-area metal halide thick film obtained in Example 3 under visible light and X-ray irradiation. The upper image is the actual image under visible light, and the lower image is the actual image under X-ray irradiation.

[0027] Figure 4 The images shown are actual images of the large-area metal halide thick film obtained in Example 4 under visible light and X-ray irradiation. The left image is the actual image under visible light, and the right image is the actual image under X-ray irradiation.

[0028] Figure 5 The images show actual images of the large-area metal halide thick film obtained in Example 5 under visible light and X-ray irradiation. The left image is the actual image under visible light, and the right image is the actual image under X-ray irradiation.

[0029] Figure 6 The images show the XRD patterns of the large-area metal halide thick films obtained in Examples 1-5.

[0030] Figure 7 PL images of the large-area metal halide thick films obtained in Examples 1-5;

[0031] Figure 8 This is a comparison diagram of the RL (Radar) of the large-area metal halide thick film obtained in Example 1 and commercial bismuth germanate (BGO) crystals.

[0032] Figure 9 The images show the actual charger and the large-area metal halide thick film obtained in Example 1 at different integration times.

[0033] Figure 10 This is a characterization diagram of the long-term stability of the large-area metal halide thick film obtained in Example 1. Detailed Implementation

[0034] This invention provides a method for preparing a large-area metal halide thick film for X-ray detection, comprising the following steps:

[0035] (1) Mix the A-site ion halide, the B-site ion halide and the solvent to obtain solution a;

[0036] (2) Mix solution a with the polymer to obtain solution b;

[0037] (3) The solution b is coated on the substrate and then annealed at low temperature to obtain a large area metal halide thick film;

[0038] The A-site ion halide is one or more of benzyltriphenylphosphine halide and cesium halide; the B-site ion halide is one or more of manganese halide, cuprous halide, and lead halide.

[0039] In step (1) of the present invention, benzyltriphenylphosphine halide is preferably one or more of benzyltriphenylphosphine bromide, benzyltriphenylphosphine iodide, and benzyltriphenylphosphine chloride; cesium halide is preferably one or more of cesium iodide, cesium bromide, and cesium chloride; manganese halide is preferably one or more of manganese chloride, manganese iodide, and manganese bromide; cuprous halide is preferably one or more of cuprous bromide, cuprous chloride, and cuprous iodide; and lead halide is preferably one or more of lead bromide, lead chloride, and lead iodide.

[0040] In step (1) of the present invention, the solvent is preferably one or more of N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, water, methanol, toluene, acetonitrile, acetic acid, hydrobromic acid, hydroiodic acid, hydrochloric acid, nitric acid, and hypophosphoric acid; in solution a, the concentration of the A-site ion halide is preferably 0.1-2 mmol / mL, more preferably 0.25-1 mmol / mL, and even more preferably 0.45-0.8 mmol / mL; the concentration of the B-site ion halide is preferably 0.1-1 mmol / L, more preferably 0.125-0.6 mmol / mL, and even more preferably 0.3-0.5 mmol / mL.

[0041] In step (2) of the present invention, the polymer is preferably one or more of polyvinylpyrrolidone, polyvinyl alcohol, polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene chloride, polylactic acid, polyethylene glycol, polybutyl acrylate and polyimide; in solution b, the concentration of the polymer is preferably 50-200 mg / mL, more preferably 80-150 mg / mL, and more preferably 100 mg / mL.

[0042] In steps (1) and (2) of the present invention, the mixing temperature is preferably 40-80°C, more preferably 50-70°C, and even more preferably 60°C; the mixing time is preferably 6-8h, more preferably 6.5-7.5h, and even more preferably 7h.

[0043] In step (3) of the present invention, the substrate is preferably a glass plate; the glass plate is a transparent glass plate.

[0044] In step (3) of the present invention, the coating is performed by scraping on an automatic scraping machine; the coating thickness is preferably 300-600 μm, more preferably 350-550 μm, and even more preferably 400-500 μm; the coating speed is preferably 1-5 mm / s, more preferably 2-4 mm / s, and even more preferably 3 mm / s.

[0045] In step (3) of the present invention, the temperature of low-temperature annealing is preferably 60-120°C, more preferably 75-110°C, and even more preferably 90-100°C; the time of low-temperature annealing is preferably 0.5-4h, more preferably 1-3h, and even more preferably 2h.

[0046] In step (3) of this invention, the purpose of annealing is to remove the solvent, and the annealing temperature is determined according to the boiling point of the solvent.

[0047] The method described in this invention enables low-temperature in-situ growth of nanocrystals of different ionic halides. This method prevents light scattering and uneven distribution of the nanocrystals while providing sufficient film thickness to absorb X-rays, thus achieving high-quality, non-agglomerated large-area metal halide thick films. Furthermore, the large-area metal halide thick films prepared by this process possess high transparency, are not easily broken, and exhibit excellent environmental stability, better meeting market demands for scintillator materials.

[0048] The present invention also provides a method for preparing a large-area metal halide thick film for X-ray detection.

[0049] The present invention also provides the application of the large-area metal halide thick film in X-ray imaging or radiation protection.

[0050] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0051] Example 1

[0052] (1) 20 mmol of benzyltriphenylphosphine bromide (C 25 H 22 PBr (denoted as BPPBr), 10 mmol of manganese bromide (MnBr2), 10 mL of methanol, 8 mL of N,N-dimethylformamide (DMF) and 2 mL of dimethyl sulfoxide (DMSO) were mixed at 60 °C for 8 h to obtain solution a;

[0053] (2) Mix 20 mL of solution a obtained in step (1), 1 g of polyvinylpyrrolidone (PVP) and 1 g of polyvinylidene fluoride (PVDF) at 60 °C for 8 h to obtain solution b;

[0054] (3) 20 mL of solution b was dropped onto a glass plate and coated into a film using an automatic coating tool. The coating thickness was 600 μm and the coating speed was 3 mm / s. After coating, the film was annealed at 70 °C for 1 h to obtain BPP2MnBr4, which is a large-area metal halide thick film.

[0055] The resulting large-area metal halide thick film measures 30cm x 22cm.

[0056] The resulting large-area metal halide thick film under visible light and X-ray irradiation is shown in the following images. Figure 1 As shown. By Figure 1 It can be seen that the large-area metal halide thick film obtained in this embodiment has high transparency, no cracks, and emits green light under X-ray irradiation.

[0057] The XRD patterns and PL images of the obtained large-area metal halide thick films are as follows: Figure 6 and Figure 7 As shown.

[0058] The RL comparison diagram of the obtained large-area metal halide thick film and the commercial bismuth germanate (BGO) crystal (model BGOD18T08-01) produced by Shanghai Shuojie Crystal Materials Co., Ltd. is shown below. Figure 8 As shown. By Figure 8 It can be seen that the obtained large-area metal halide thick film has a detection performance far superior to that of commercial bismuth germanate (BGO) crystals and other materials.

[0059] The resulting large-area metal halide thick film images of the charger at different integration times are shown below. Figure 9 As shown.

[0060] The stability of the obtained large-area metal halide thick film is as follows: Figure 10 As shown. By Figure 10 It can be seen that the obtained large-area metal halide thick film does not show significant performance degradation after being placed in a normal temperature and pressure atmospheric environment for more than 2 months, which means it has excellent environmental stability.

[0061] Example 2

[0062] (1) 20 mmol of benzyltriphenylphosphine bromide (C 25 H 22 PBr (denoted as BPPBr), 10 mmol of manganese chloride (MnCl2), 10 mL of methanol, 8 mL of N,N-dimethylformamide (DMF) and 2 mL of dimethyl sulfoxide (DMSO) were mixed at 60 °C for 8 h to obtain solution a;

[0063] (2) Mix 20 mL of solution a obtained in step (1), 1 g of polyvinylpyrrolidone (PVP) and 1 g of polyvinylidene fluoride (PVDF) at 60 °C for 8 h to obtain solution b;

[0064] (3) 20 mL of solution b was dropped onto the glass and coated into a film using an automatic coating tool. The coating thickness was 600 μm and the coating speed was 3 mm / s. After coating, the film was annealed at 70 °C for 1 h to obtain BPP2MnBr2Cl2, which is a large-area metal halide thick film.

[0065] The resulting large-area metal halide thick film under visible light and X-ray irradiation is shown in the following images. Figure 2 As shown. By Figure 2 It can be seen that the large-area metal halide thick film obtained in this embodiment has high transparency, no cracks, and emits green light under X-ray irradiation.

[0066] The XRD patterns and PL images of the obtained large-area metal halide thick films are as follows: Figure 6 and Figure 7 As shown.

[0067] Example 3

[0068] (1) Add 20 mmol of benzyltriphenylphosphine chloride (C 25 H 22 PCl (denoted as BPPCl), 10 mmol of manganese chloride (MnCl2), 10 mL of methanol, 8 mL of N,N-dimethylformamide (DMF) and 2 mL of dimethyl sulfoxide (DMSO) were mixed at 60 °C for 8 h to obtain solution a;

[0069] (2) Mix 20 mL of solution a obtained in step (1), 1 g of polyvinylpyrrolidone (PVP) and 1 g of polyvinylidene fluoride (PVDF) at 60 °C for 8 h to obtain solution b;

[0070] (3) 20 mL of solution b was dropped onto the glass and coated into a film using an automatic coating tool. The coating thickness was 600 μm and the coating speed was 3 mm / s. After coating, the film was annealed at 70 °C for 1 h to obtain BPP2MnCl4, which is a large-area metal halide thick film.

[0071] The resulting large-area metal halide thick film under visible light and X-ray irradiation is shown in the following images. Figure 3 As shown. By Figure 3 It can be seen that the large-area metal halide thick film obtained in this embodiment has high transparency, no cracks, and emits green light under X-ray irradiation.

[0072] The XRD patterns and PL images of the obtained large-area metal halide thick films are as follows: Figure 6 and Figure 7 As shown.

[0073] Example 4

[0074] (1) Mix 10 mmol of cesium bromide (CsBr), 5 mmol of lead bromide (PbBr2) and 40 mL of N,N-dimethylformamide (DMF) at 40 °C for 8 h to obtain solution a;

[0075] (2) Mix 40 mL of solution a obtained in step (1), 1 g of polyvinylpyrrolidone (PVP) and 1 g of polyvinylidene fluoride (PVDF) at 60 °C for 8 h to obtain solution b;

[0076] (3) 20 mL of solution b was dropped onto a glass plate and coated into a film using an automatic coating tool. The coating thickness was 500 μm and the coating speed was 3 mm / s. After coating, the film was annealed at 120 °C for 2 h to obtain CsPbBr3, which is a large-area metal halide thick film.

[0077] The resulting large-area metal halide thick film has a length × width of 25cm × 25cm.

[0078] The resulting large-area metal halide thick film under visible light and X-ray irradiation is shown in the following images. Figure 4 As shown. By Figure 4 It can be seen that the large-area metal halide thick film obtained in this embodiment has high transparency, no cracks, and emits green light under X-ray irradiation.

[0079] The XRD patterns and PL images of the obtained large-area metal halide thick films are as follows: Figure 6 and Figure 7 As shown.

[0080] Example 5

[0081] (1) Mix 9 mmol of cesium chloride (CsCl), 6 mmol of cuprous chloride (CuCl), 10 mL of deionized water and 10 mL of N,N-dimethylformamide (DMF) at 40 °C for 8 h to obtain solution a;

[0082] (2) Mix 20 mL of solution a obtained in step (1), 0.5 g of polyvinylpyrrolidone (PVP) and 0.5 g of polyvinylidene fluoride (PVDF) at 60 °C for 8 h to obtain solution b;

[0083] (3) 20 mL of solution b was dropped onto a glass plate and coated into a film using an automatic coating tool. The coating thickness was 500 μm and the coating speed was 3 mm / s. After coating, the film was annealed at 90 °C for 2 h to obtain Cs3Cu2Cl5, which is a large-area metal halide thick film.

[0084] The resulting large-area metal halide thick film has a length × width of 15cm × 15cm.

[0085] The resulting large-area metal halide thick film under visible light and X-ray irradiation is shown in the following images. Figure 5 As shown. By Figure 5 It can be seen that the large-area metal halide thick film obtained in this embodiment has high transparency, no cracks, and emits blue light under X-ray irradiation.

[0086] The XRD patterns and PL images of the obtained large-area metal halide thick films are as follows: Figure 6 and Figure 7 As shown.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a large-area metal halide thick film for X-ray detection, characterized in that, Includes the following steps: (1) Mix the A-site ion halide, the B-site ion halide and the solvent to obtain solution a; (2) Mix solution a with the polymer to obtain solution b; (3) The solution b is coated on the substrate and then annealed at low temperature to obtain a large area metal halide thick film; The A-site ion halide is benzyltriphenylphosphine halide; the B-site ion halide is one or more of manganese halide, cuprous halide, and lead halide; In solution a, the concentration of the A-site ion halide is 0.1–2 mmol / mL; the concentration of the B-site ion halide is 0.1–1 mmol / L. In solution b, the concentration of the polymer is 50–200 mg / mL.

2. The method for preparing a large-area metal halide thick film for X-ray detection according to claim 1, characterized in that, In step (1), the solvent is one or more of N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, water, methanol, toluene, acetonitrile, acetic acid, hydrobromic acid, hydroiodic acid, hydrochloric acid, nitric acid, and hypophosphoric acid.

3. The method for preparing a large-area metal halide thick film for X-ray detection according to claim 2, characterized in that, In step (2), the polymer is one or more of the following: polyvinylpyrrolidone, polyvinyl alcohol, polymethyl methacrylate, polyvinylidene fluoride, polyvinylidene chloride, polylactic acid, polyethylene glycol, polybutyl acrylate, and polyimide.

4. The method for preparing a large-area metal halide thick film for X-ray detection according to any one of claims 1 to 3, characterized in that, In steps (1) and (2), the mixing temperature is 40-80°C and the mixing time is 6-8h.

5. The method for preparing a large-area metal halide thick film for X-ray detection according to claim 4, characterized in that, In step (3), the substrate is a glass plate.

6. The method for preparing a large-area metal halide thick film for X-ray detection according to claim 5, characterized in that, In step (3), the coating thickness is 300-600 μm and the coating speed is 1-5 mm / s.

7. The method for preparing a large-area metal halide thick film for X-ray detection according to claim 5 or 6, characterized in that, In step (3), the temperature of low-temperature annealing is 60-120℃, and the time of low-temperature annealing is 0.5-4h.

8. The large-area metal halide thick film prepared by the method for preparing large-area metal halide thick films for X-ray detection according to any one of claims 1 to 7.

9. The application of the large-area metal halide thick film of claim 8 in X-ray imaging or radiation protection.

Images