Perovskite composite film scintillator for neutron gamma discrimination and preparation method and application thereof

Abstract

The invention discloses a perovskite composite film scintillator for neutron gamma discrimination and a preparation method and application thereof, and relates to the technical field of nuclear radiation mixed field detection. The composite film scintillator comprises an organic carrier, a perovskite material and a plastic film, the perovskite material is embedded in the organic carrier and is coupled with the plastic film; wherein the organic carrier is a plastic matrix, and the mass ratio of the organic carrier to the plastic matrix is 40-80%. The preparation method of the perovskite composite film scintillator comprises the following steps: dissolving raw materials in N, N-dimethylformamide, heating and stirring to obtain a precursor solution, and cooling to normal temperature to obtain a primary solution; and paving a plastic film on a substrate, dropwise adding the preliminary solution to enable the preliminary solution to be uniformly attached to the surface of the plastic film, and performing annealing treatment and cooling to obtain the perovskite composite film scintillator. The perovskite composite film scintillator which has the characteristics of high efficiency, stability, flexibility and low cost is developed, and the application bottleneck of the existing neutron gamma discrimination technology is broken through.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation mixed field detection, in particular to a perovskite composite film scintillator for neutron-gamma discrimination, a preparation method and application thereof. BACKGROUND

[0002] The detection and discrimination technology of neutrons and gamma rays has important application value in the fields of nuclear radiation detection, nuclear safety monitoring and high-energy physics experiments. Traditional scintillator materials have many limitations in their application in this field, making it difficult to meet the detection needs in complex scenarios. On the one hand, although organic liquid scintillators can detect neutrons and gamma rays to some extent, the preparation process often involves toxic solvents, which not only have complex process and poor environmental friendliness, but also have high cost. Moreover, due to the material properties, it is difficult to achieve flexible and large-area preparation, and it cannot meet the needs of flexible devices in special scenarios. On the other hand, inorganic crystal scintillators represented by NaI(Tl) and CsI(Tl) have high detection efficiency, but their preparation usually relies on complex processes such as Bridgman method under high temperature and high pressure, which has the defects of high energy consumption and long preparation period. Moreover, the material itself is brittle and difficult to process into flexible devices, which greatly limits its expansion in special application scenarios such as non-planar and bendable.

[0003] In recent years, perovskite materials have become a research hotspot in the field of radiation detection due to their excellent carrier transport performance, high luminous efficiency and adjustable band gap characteristics, providing a new direction for breaking through the bottleneck of traditional materials. However, existing research on perovskite materials has mainly focused on the optimization of the luminescence performance of a single excitation source (such as X-ray or ultraviolet light), and there is a significant shortcoming in the multi-modal excitation response capability, especially in responding to mixed radiation of neutrons and gamma rays. This cannot meet the actual needs of simultaneous detection of multiple particles or rays in nuclear radiation mixed fields. Moreover, traditional perovskite scintillators usually exist in the form of single crystals, and their preparation methods are complex and costly, making it difficult to achieve large-area and flexible preparation, which further limits their application in large-scale detection systems.

[0004] Although some studies have attempted to combine perovskite with a polymer matrix to prepare flexible thin film scintillators, most of these composite materials are still limited to the detection of X-rays or ultraviolet light. The core problem lies in the lack of effective capture and response capability for neutrons. From the perspective of detection principle, neutron detection usually relies on the presence of a large number of hydrogen atoms or other light elements in the material to achieve effective identification of neutrons through nuclear recoil effect. However, conventional perovskite materials and existing perovskite-polymer composite systems have inherent deficiencies in this regard, making it difficult to balance the performance of gamma ray detection and the need for neutron detection.

[0005] In summary, current technologies for detecting mixed neutron and gamma-ray fields still generally face key challenges such as complex material preparation, limited detection modes, insufficient flexibility, and low neutron detection efficiency. Developing a composite thin-film scintillator that combines high neutron detection efficiency, high gamma response capability, simple preparation, low cost, and good flexibility and stability to achieve efficient discrimination and simultaneous detection of neutrons and gamma rays has become a core technical challenge urgently needing to be solved in the field of radiation detection. This is of great significance for promoting technological progress in nuclear safety monitoring, radiation protection, and high-energy physics experiments. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a perovskite composite thin film scintillator for neutron-gamma discrimination, its preparation method and application. A perovskite composite thin film scintillator with high efficiency, stability, flexibility and low cost has been successfully developed, which effectively breaks through the application bottleneck of the existing neutron-gamma discrimination technology and has important practical value and promotion prospects in the field of nuclear technology.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A perovskite composite thin film scintillator for neutron gamma discrimination includes an organic carrier, a perovskite material, and a plastic film;

[0009] The perovskite material is embedded in an organic carrier and coupled to a plastic film; wherein the organic carrier is a plastic matrix, accounting for 40% to 80% by mass.

[0010] Furthermore, the perovskite material is selected from at least one of Cs3Cu2I5, CsCu2I3, CsPbBr3, and CsCuCl3.

[0011] Furthermore, the plastic film is selected from one of polyethylene film, polyester film, polypropylene film, polyvinyl chloride film, and polystyrene film.

[0012] Furthermore, the total thickness of the perovskite composite thin film scintillator is not less than 0.1 mm.

[0013] Furthermore, the plastic matrix accounts for 60% to 80% of the total mass.

[0014] On the other hand, the present invention also provides a method for preparing the above-mentioned perovskite composite thin film scintillator, comprising the following steps:

[0015] S1, the plastic matrix and the A-site source and B-site source of perovskite are mixed in a certain ratio to obtain a mixed raw material; wherein the A-site source is a Cs-containing halide and the B-site source is a Cu or Pb-containing halide.

[0016] S2, Dissolve the mixed raw materials in N,N-dimethylformamide, and obtain a stable and uniform precursor solution by heating and stirring;

[0017] S3, cool the precursor solution to room temperature to obtain a preliminary solution before coating;

[0018] S4, lay the cleaned plastic film on the substrate, drop the preliminary solution from step S3 onto the substrate, and coat the plastic film so that the preliminary solution is evenly adhered to the surface of the plastic film.

[0019] S5. The coated plastic film is annealed and cooled to obtain a perovskite composite film scintillator.

[0020] Furthermore, in step S2, the heating and stirring temperature is 60℃~70℃, and the stirring time is 10h~14h.

[0021] Furthermore, in step S4, the coating method is spin coating or blade coating.

[0022] Furthermore, in step S5, the annealing temperature is 60℃~80℃ and the time is 10min~20min.

[0023] The present invention also provides applications of the above-mentioned perovskite composite thin film scintillator, including its application in neutron gamma discrimination, nuclear radiation detection, nuclear safety monitoring or high-energy physics experiments.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) This invention employs an in-situ deposition method, which can rapidly prepare perovskite composite films under mild conditions, avoiding the complex process, high energy consumption, and long cycle problems of traditional single crystal growth methods (such as the Bridgman method). This method is simple, easy to control, and can achieve the preparation of large-size films with good uniformity, significantly reducing production costs and making it suitable for large-scale applications.

[0026] (2) The composite thin film scintillator in this invention cleverly combines the synergistic effect of organic and inorganic components. The hydrogen atoms in the organic plastic matrix provide an efficient neutron capture cross section, enhancing the fast neutron detection efficiency; while the high atomic number (high Z) elements in the inorganic perovskite effectively improve the detection sensitivity of gamma photons, thereby realizing synchronous detection and discrimination in the neutron-gamma mixed radiation field.

[0027] (3) The thin-film scintillator in this invention has good flexibility and mechanical strength, and can be used on curved or flexible substrates to adapt to complex application scenarios. At the same time, it exhibits excellent chemical and physical stability in air, is not prone to aging or damage, and extends its service life.

[0028] (4) Unlike traditional scintillators that only respond to a single radiation source, the composite film in this invention can respond to multiple excitation sources such as neutrons, gamma rays and X-rays at the same time, realizing multi-mode radiation detection, which is especially suitable for fields such as nuclear radiation mixed field detection, nuclear safety monitoring and high-energy physics experiments.

[0029] (5) This invention is not limited to a specific perovskite type and can be widely applied to various perovskite materials such as Cs3Cu2I5, CsCu2I3, CsPbBr3, and CsCuCl3. By coupling with plastic films (such as PE, PET, PP, etc.), the deficiency of insufficient neutron detection capability of pure perovskite films is effectively compensated. Its neutron detection efficiency is several times higher than that of uncomposite films, and it has high signal resolution capability.

[0030] (6) Experimental and simulation results (such as XRD, PL, SEM and Monte Carlo analysis) in this invention show that the composite film has the characteristics of good crystallinity, high luminous efficiency and clear signal discrimination, and has the advantages of high resolution, high detection efficiency and easy integration, providing a reliable material basis for the next generation of flexible and multifunctional radiation detectors. Attached Figure Description

[0031] Figure 1 A schematic diagram illustrating the discrimination principle of perovskite composite thin film scintillators;

[0032] Figure 2 This is a sample image of the perovskite composite film prepared in Example 1 under natural light;

[0033] Figure 3 This is a sample image of the perovskite composite film prepared in Example 1 under ultraviolet light;

[0034] Figure 4 The X-ray diffraction (XRD) pattern of the perovskite composite thin film prepared in Example 1;

[0035] Figure 5 A comparison diagram of neutron gamma signal pulses from a composite thin-film scintillator;

[0036] Figure 6 The X-ray diffraction (XRD) pattern of the perovskite composite thin film prepared in Example 2;

[0037] Figure 7 PL for the perovskite composite films prepared in Examples 1 and 2;

[0038] Figure 8 SEM images of the perovskite composite films prepared in Examples 1 and 2;

[0039] Figure 9 The X-ray diffraction (XRD) pattern of the perovskite composite thin film prepared in Example 3;

[0040] Figure 10 The X-ray diffraction (XRD) pattern of the perovskite composite thin film prepared in Example 4;

[0041] Figure 11 A comparison chart of neutron detection efficiency for Monte Carlo simulations of composite thin-film scintillators;

[0042] Figure 12 , 13 The perovskite films prepared for comparative examples 1 and 2 were in 241 Scatter plot of mixed radiation neutron gamma detected by Am-Be radioactive source;

[0043] Figures 14-16 The perovskite composite films prepared for Examples 1-3 are shown in 241 Scatter plot of mixed radiation neutron gamma detected by an Am-Be radioactive source. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0045] To address the issue that traditional perovskite materials in neutron-gamma discrimination technology typically require single-crystal applications, and that single-crystal preparation often relies on the Bridgman method—a method that is cumbersome, time-consuming, and energy-intensive—this invention proposes a method for preparing perovskite composite films using in-situ deposition. This method can obtain high-quality perovskite composite films in a very short time, and these films can be coupled with organic plastic films for neutron-gamma detection applications, exhibiting excellent neutron-gamma discrimination performance.

[0046] The perovskite composite thin-film scintillator for neutron-gamma discrimination provided by this invention includes an organic carrier and a perovskite material embedded therein, coupled with a plastic film; wherein the mass proportion of the plastic matrix is ​​40%~80%, preferably 60%~80%. If the mass proportion of the plastic matrix is ​​insufficient, the neutron capture efficiency of the composite thin-film scintillator will decrease, and the detection efficiency will be reduced; as the mass proportion of the plastic matrix increases, the neutron capture efficiency improves, but the light self-absorption effect of the material will also be correspondingly enhanced.

[0047] In this invention, perovskite material is incorporated into a plastic matrix as a single fluorescent substance. Its large Stokes shift ensures light migration and reduces light absorption, thereby improving light receiving efficiency. This mode not only leverages the perovskite's response to gamma particles but also utilizes its function as a fluorescent substance, significantly reducing fabrication difficulty and facilitating the preparation of large-size materials, thus expanding the detection coverage area. Furthermore, this scintillator possesses a certain degree of flexibility, making it suitable for a wide range of applications and a promising multimodal radiation detection scintillator material.

[0048] The aforementioned perovskite composite thin-film scintillator is composed of a plastic matrix, perovskite, and a plastic film, with a total thickness of not less than 0.1 mm. The perovskite material can be selected from Cs3Cu2I5, CsCu2I3, CsPbBr3, CsCuCl3, etc.; the plastic film material can be selected from polyethylene (PE) film, polyester (PET) film, polypropylene (PP) film, polyvinyl chloride (PVC) film, and polystyrene (PS) film.

[0049] This invention provides a method for preparing the above-mentioned perovskite composite thin film scintillator, comprising:

[0050] (1) Place the plastic matrix polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF) into a glass bottle with a magnetic rotor; place the A-site source and B-site source required for the synthesis of perovskite into the same glass bottle according to the molar ratio to obtain mixed raw materials; wherein, the A-site source is a Cs-containing halide (including CsI, CsBr, CsCl, etc.), and the B-site source is a Cu or Pb-containing halide (including CuI, CuCl, PbBr2, etc.), and the specific selection needs to match the chemical composition of the target perovskite material;

[0051] (2) The mixed raw materials in step (1) are dissolved in N,N-dimethylformamide (DMF) by heating and stirring to obtain a stable and uniform precursor solution;

[0052] (3) Cool the precursor solution in step (2) to room temperature at room temperature to obtain the preliminary solution before coating;

[0053] (4) The cleaned plastic film is laid on a substrate of sufficient size, high temperature resistance and uniform smoothness. A suitable amount of the preliminary solution obtained in step (3) is dripped on it. The solution is coated so that it is evenly attached to the surface of the plastic film. Then it is quickly transferred to a vacuum constant temperature drying oven and annealed for 10~20 minutes to form a film. Finally, it is taken out and cooled to room temperature to obtain a perovskite composite film scintillator for neutron gamma discrimination.

[0054] A schematic diagram of the discrimination principle of the perovskite composite thin film scintillator prepared in this invention is shown below. Figure 1 As shown in the figure, the basic structure of the scintillator, composed of a plastic matrix, perovskite, and plastic film, is clearly displayed, demonstrating its wide applicability to various materials.

[0055] The perovskite composite thin film scintillator prepared above can be used for the detection and discrimination of gamma rays and neutrons; it is suitable for detector scenarios with flexibility requirements; and it can also be applied to detectors in fields such as nuclear radiation detection, nuclear safety monitoring, and radiation mixing fields in high-energy physics experiments.

[0056] The following description, in conjunction with specific embodiments, provides further details.

[0057] Example 1

[0058] This embodiment provides a method for preparing a Cs3Cu2I5 perovskite composite thin film scintillator for neutron gamma discrimination, including the following steps:

[0059] (1) Weigh 3 mmol CsI, 2 mmol CuI, 1 g PMMA and 1 g PVDF respectively to obtain raw materials; dissolve the raw materials in DMF to obtain precursor solution.

[0060] (2) Heat the precursor solution to 60°C and stir it with a magnetic stirrer at 60°C for 12 hours to fully dissolve it, so as to obtain a stable and uniform precursor solution.

[0061] (3) Under room temperature conditions, the precursor solution in step (2) is cooled to room temperature to obtain the preliminary solution before coating; the 1 mm PE film is ultrasonically cleaned with ethanol ultrasonic cleaning solution for 5 min, and then dried with high-purity inert gas for 1 h to obtain a clean PE film.

[0062] (4) Lay the PE film on a quartz glass substrate of sufficient size, high temperature resistance and uniform smoothness, drop an appropriate amount of preliminary solution on it, and coat it so that the solution is uniformly attached to the surface of the plastic film; the coating method in this step is spin coating.

[0063] (5) Quickly transfer the plastic film from step (4) to a constant temperature forced-air oven and anneal at 60°C for 15 minutes to obtain the Cs3Cu2I5@PMMA / PVDF@PE composite film. Measurements show that the thickness of the plastic matrix containing the perovskite material in the finished composite film prepared in this embodiment is 0.1 mm.

[0064] Figure 2 This is a sample image of the perovskite composite film prepared in Example 1 under natural light. It can be directly observed that the film material has extremely strong flexibility, which provides a basis for its application in special scenarios such as non-planar and flexible materials. Figure 3 The image shows the perovskite composite film prepared in Example 1 under ultraviolet light, clearly demonstrating the excellent luminescence performance of the film and verifying its core characteristics as a scintillator material. Figure 4 The X-ray diffraction (XRD) pattern of the perovskite composite film prepared in this embodiment shows that the peaks are sharp and there are no obvious impurity peaks, indicating that the composite film has good crystallinity.

[0065] Figure 5This is a comparison diagram of neutron and gamma signal pulses in a composite thin-film scintillator (this diagram is universal; since the pulse signals of any neutron and gamma are different, each particle is represented by a pulse in this diagram for illustrative purposes). It can visually distinguish the differences between the pulse signals of neutrons and gamma rays, providing a signal basis for the effective differentiation between the two.

[0066] Example 2

[0067] This embodiment provides a method for preparing a CsCu2I3 perovskite composite thin film scintillator for neutron gamma discrimination, including the following steps:

[0068] (1) Weigh 1 mmol CsI, 2 mmol CuI, 0.5 g PMMA and 0.5 g PVDF respectively to obtain raw materials; dissolve the raw materials in DMF to obtain precursor solution.

[0069] (2) Heat the precursor solution to 60°C and stir it with a magnetic stirrer at 60°C for 12 hours to fully dissolve it, so as to obtain a stable and uniform precursor solution.

[0070] (3) Under room temperature conditions, the precursor solution in step (2) is cooled to room temperature to obtain the preliminary solution before coating; the 2 mm PE film is ultrasonically cleaned with ethanol ultrasonic cleaning solution for 5 min, and then dried with high-purity inert gas for 1 h to obtain a clean PE film.

[0071] (4) Lay the PE film on a quartz glass substrate of sufficient size, high temperature resistance and uniform smoothness, drop an appropriate amount of preliminary solution on it, and coat it so that the solution is uniformly attached to the surface of the plastic film; the coating method in this step is scraping.

[0072] (5) Quickly transfer the film from step (4) to a constant temperature forced-air oven for annealing. After annealing at 60°C for 15 minutes, the CsCu2I3@PMMA / PVDF@PE composite film can be obtained. According to the measurement, the thickness of the plastic matrix with embedded perovskite material in the finished composite film prepared in this embodiment is 0.12 mm.

[0073] Figure 6 The X-ray diffraction (XRD) pattern of the perovskite composite thin film prepared in Example 2 is shown below. Figure 4 The consistent trend demonstrates that composite films with different perovskite components can maintain good crystallinity under this preparation process. Figure 7 The PL spectra of the perovskite composite films prepared in Examples 1 and 2 show that their excitation wavelengths match the response range of most photomultiplier tubes, indicating that the thin-film scintillator has compatibility with practical detection applications. Figure 8SEM images of the perovskite composite films prepared in Examples 1 and 2 clearly show that the perovskite crystals are uniformly dispersed in the plastic matrix and tightly bonded to the matrix, verifying the excellent composite properties of the materials.

[0074] Example 3

[0075] This embodiment provides a method for preparing a CsPbBr3 perovskite composite thin film scintillator for neutron gamma discrimination, including the following steps:

[0076] (1) Weigh 1 mmol CsBr, 1 mmol PbBr2, 0.4 g PMMA and 0.6 g PVDF respectively to obtain the raw materials; dissolve the raw materials in DMF to obtain the precursor solution.

[0077] (2) Heat the precursor solution to 70°C and stir it with a magnetic stirrer at 70°C for 10 hours to fully dissolve it, so as to obtain a stable and uniform precursor solution.

[0078] (3) Under room temperature conditions, the precursor solution in step (2) is cooled to room temperature to obtain the preliminary solution before coating; the 1 mm PET film is ultrasonically cleaned with isopropanol ultrasonic cleaning solution for 10 min, and then dried with high-purity inert gas for 40 min to obtain a clean PET film.

[0079] (4) Lay the PET film on a sufficiently large, high-temperature resistant and uniformly smooth indium tin oxide glass substrate, drop an appropriate amount of preliminary solution on it, and coat it so that the solution is uniformly attached to the PET film; the coating method in this step is spin coating.

[0080] (5) Quickly transfer the film from step (4) to a constant temperature forced-air oven for annealing. After annealing at 80°C for 20 minutes, the CsPbBr3@PMMA / PVDF@PET film can be obtained. According to the measurement, the thickness of the plastic matrix with embedded perovskite material in the finished composite film prepared in this embodiment is 0.92 mm.

[0081] Figure 9 The X-ray diffraction (XRD) pattern of the perovskite composite film prepared in Example 3 further confirms the applicability of the process of the present invention to different perovskite materials, and the film crystallization quality is stable.

[0082] Example 4

[0083] This embodiment provides a method for preparing a CsCuCl3 perovskite composite thin film scintillator for neutron gamma discrimination, including the following steps:

[0084] (1) Weigh 1 mmol CsCl, 1 mmol CuCl, 0.5 g PMMA and 0.5 g PVDF respectively to obtain raw materials. Dissolve the raw materials in DMF to obtain a precursor solution.

[0085] (2) Heat the precursor solution to 65°C and stir it with a magnetic stirrer at 65°C for 14 hours to fully dissolve it, so as to obtain a stable and uniform precursor solution.

[0086] (3) Under room temperature conditions, the precursor solution in step (2) is cooled to room temperature to obtain the preliminary solution before coating; the 2 mm PS film is ultrasonically cleaned for 8 min with a mixed solution of ethanol and acetone (volume ratio 1:1), and then dried with high-purity inert gas for 50 min to obtain a clean PS film.

[0087] (4) Fix the PS film on a quartz glass substrate of sufficient size, high temperature resistance and uniform smoothness, drop an appropriate amount of preliminary solution on it, and coat it so that the solution is uniformly attached to the PS film; the coating method in this step is spin coating, the spin coating speed is 500 rpm and the time is 30s.

[0088] (5) Quickly transfer the film from step (4) to a constant temperature forced-air oven for annealing. After annealing at 70°C for 18 minutes, the CsCuCl3@PMMA / PVDF@PS composite film can be obtained. According to the measurement, the thickness of the plastic matrix with embedded perovskite material in the finished composite film prepared in this embodiment is 0.11 mm.

[0089] Figure 10 The X-ray diffraction (XRD) pattern of the perovskite composite film prepared in Example 4 further verifies the versatility of the preparation method of the present invention, showing that different perovskite-plastic film composite systems can form well-crystallized film materials.

[0090] Comparative Example 1

[0091] This comparative example provides a method for preparing a Cs3Cu2Cl5 perovskite composite thin film scintillator, including the following steps:

[0092] (1) Weigh 3 mmol CsCl, 2 mmol CuCl, 1 g PMMA and 1 g PVDF respectively to obtain raw materials; dissolve the raw materials in DMF to obtain precursor solution.

[0093] (2) Heat the precursor solution to 65°C and stir it with a magnetic stirrer at 65°C for 20 hours to fully dissolve it and obtain a stable homogeneous solution.

[0094] (3) Cool the uniform solution to room temperature at room temperature to obtain the preliminary solution before coating; drop an appropriate amount of the preliminary solution onto the quartz glass substrate and coat it so that the solution is uniformly attached to the substrate; the coating method in this step is spin coating, the spin coating speed is 500 rpm and the time is 30 s.

[0095] (4) The precursor film from step (4) was quickly transferred to a constant temperature forced-air oven for annealing. After annealing at 60°C for 20 min, a CsCuCl3@PMMA / PVDF composite film was obtained. According to the measurement, the thickness of the plastic matrix with embedded perovskite material in the finished composite film prepared in this comparative example was 0.10 mm.

[0096] Comparative Example 2

[0097] This comparative example provides a method for preparing a CsCu2I3 perovskite composite thin film scintillator, including the following steps:

[0098] (1) Weigh 1 mmol CsI, 2 mmol CuI, 1 g PMMA and 1 g PVDF respectively to obtain raw materials; dissolve the raw materials in DMF to obtain precursor solution.

[0099] (2) Heat the precursor solution to 65°C and stir it with a magnetic stirrer at 65°C for 20 hours to fully dissolve it and obtain a stable homogeneous solution.

[0100] (3) Cool the uniform solution to room temperature at room temperature to obtain the preliminary solution before coating; drop an appropriate amount of the preliminary solution onto the quartz glass substrate and coat it so that the solution is uniformly attached to the substrate; the coating method in this step is spin coating, the spin coating speed is 500 rpm and the time is 30 s.

[0101] (4) The precursor film from step (4) was quickly transferred to a constant temperature forced-air oven for annealing. After annealing at 60°C for 20 min, a CsCu2I3@PMMA / PVDF composite film was obtained. According to the measurement, the thickness of the plastic matrix with embedded perovskite material in the composite film prepared in this comparative example was 0.11 mm.

[0102] Figure 11 The diagram shows a comparison of neutron detection efficiency in Monte Carlo simulations of composite thin-film scintillators. The control group used the composite thin film prepared in Comparative Example 1, while the other two groups used composite thin films prepared in Examples 1 and 2, respectively. The results clearly show that adding the plastic film significantly improves neutron detection efficiency, demonstrating the crucial role of the plastic film in neutron capture.

[0103] Figure 12 and Figure 13The perovskite films prepared in Comparative Example 1 and Comparative Example 2, respectively, were... 241 The mixed radiation neutron-gamma scatter plot detected under the Am-Be radiation source shows that the composite system without the plastic film has difficulty effectively distinguishing between neutron and gamma ray signals, resulting in poor discrimination. In contrast, the perovskite composite films prepared in Examples 1-3 show mixed radiation neutron-gamma scatter plots under the same radiation source as shown in the image. Figure 14 (Example 1) Figure 15 (Example 2) Figure 16 As shown in (Example 3), it is similar to Figure 12 , 13 In stark contrast, the composite plastic film exhibits a clear clustering effect between neutron and gamma-ray signals, demonstrating significant signal discrimination capabilities.

[0104] The above embodiments are merely one of the preferred embodiments of the present invention and should not be used to limit the scope of protection of the present invention. Any modifications or refinements made to the main design concept and spirit of the present invention that are not of substantial significance, but solve the same technical problem as the present invention, should be included within the scope of protection of the present invention.

Claims

1. A perovskite composite thin-film scintillator for neutron gamma discrimination, characterized in that, Including organic carriers, perovskite materials, and plastic films; The perovskite material is embedded in an organic carrier and coupled to a plastic film; wherein the organic carrier is a plastic matrix, accounting for 40% to 80% by mass.

2. The perovskite composite thin-film scintillator for neutron gamma discrimination according to claim 1, characterized in that, The perovskite material is selected from at least one of Cs3Cu2I5, CsCu2I3, CsPbBr3, and CsCuCl3.

3. The perovskite composite thin-film scintillator for neutron gamma discrimination according to claim 1, characterized in that, The plastic film is selected from one of polyethylene film, polyester film, polypropylene film, polyvinyl chloride film, and polystyrene film.

4. The perovskite composite thin-film scintillator for neutron gamma discrimination according to claim 1, characterized in that, The total thickness of the perovskite composite thin film scintillator is not less than 0.1 mm.

5. The perovskite composite thin-film scintillator for neutron gamma discrimination according to claim 1, characterized in that, The plastic matrix accounts for 60% to 80% of the total mass.

6. A method for preparing a perovskite composite thin film scintillator as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1, the plastic matrix and the A-site source and B-site source of perovskite are mixed in a certain ratio to obtain a mixed raw material; wherein the A-site source is a Cs-containing halide and the B-site source is a Cu or Pb-containing halide. S2, Dissolve the mixed raw materials in N,N-dimethylformamide, and obtain a stable and uniform precursor solution by heating and stirring; S3, cool the precursor solution to room temperature to obtain a preliminary solution before coating; S4, lay the cleaned plastic film on the substrate, drop the preliminary solution from step S3 onto the substrate, and coat the plastic film so that the preliminary solution is evenly adhered to the surface of the plastic film. S5. The coated plastic film is annealed and cooled to obtain a perovskite composite film scintillator.

7. The method according to claim 6, characterized in that, In step S2, the heating and stirring temperature is 60℃~70℃, and the stirring time is 10h~14h.

8. The method according to claim 7, characterized in that, In step S4, the coating method is either spin coating or blade coating.

9. The method according to claim 8, characterized in that, In step S5, the annealing temperature is 60℃~80℃ and the time is 10min~20min.

10. The application of a perovskite composite thin film scintillator as described in any one of claims 1 to 5 in neutron gamma discrimination, nuclear radiation detection, nuclear safety monitoring, or high-energy physics experiments.

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