In-situ laminated growth method of perovskite scintillator composite film and product and application thereof
By stacking perovskite nanocrystals with polymer precursor solutions using an in-situ layering growth method, the uniformity and stability issues of perovskite scintillator films were solved, enabling high-resolution applications in EUV and X-ray multicolor imaging.
Patent Information
- Application Number
- CN202511244216.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2025-12-12
AI Technical Summary
Existing perovskite scintillator films suffer from poor uniformity and stability due to nanocrystal aggregation during long-term use, which affects imaging quality and lacks effective response to EUV and X-ray bands.
An in-situ stacked growth method was used to stack perovskite nanocrystals such as FAPbI3, CsPbI3, CsPbBr3 and Cs3Cu2I5 with polymer precursor solutions on the substrate surface to form a perovskite scintillator composite film. The strong interaction between the polymer matrix and the perovskite nanocrystals inhibited the agglomeration of nanocrystals and improved the uniformity and stability of the film.
High-resolution multicolor imaging of perovskite scintillator thin films in EUV and X-ray bands was achieved, improving the uniformity and stability of the films and making them suitable for EUV and X-ray multicolor curved surface imaging.
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Figure CN121108974A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of photoelectric materials, and particularly relates to an in-situ layer-by-layer growth method of a perovskite scintillator composite film, a product thereof and application. BACKGROUND
[0002] A multispectral camera can simultaneously capture the spectral response of multiple spectral bands, thereby realizing accurate characterization of target characteristics, and has broad application prospects in the fields of medical diagnosis, environmental science, national defense security and the like. However, the response bands of the current multispectral camera are very limited, mainly concentrated in the visible light to near-infrared region, and lack of response to the X-ray to EUV band. The multispectral camera with EUV and X-ray band response can effectively collect the information inside the object, and is suitable for distinguishing the subtle differences in material composition and density and other complex scenes. Perovskite nanocrystals can effectively absorb the energy in the X-ray to EUV band due to their high absorption coefficient and excellent scintillator characteristics, and generate characteristic photoluminescence. However, the perovskite scintillator film is usually prepared by a physical mixing method of encapsulating perovskite nanocrystals and a polymer matrix. The perovskite scintillator film prepared by the physical mixing method will inevitably have nanocrystal agglomeration phenomenon during long-term use, affecting the uniformity of the film, and ultimately leading to the damage of the imaging quality. SUMMARY
[0003] In view of the above technical problems, the application provides an in-situ layer-by-layer growth method of a perovskite scintillator composite film, a product thereof and application. The in-situ layer-by-layer growth method can effectively solve the above bottleneck and ensure the uniformity and stability of the film during long-term use. The method is suitable for perovskite scintillator film systems with EUV and different X-ray energy responses. By hetero-stacking multiple layers of films with different energy responses, four-channel EUV and X-ray multicolor curved surface imaging can be realized. This method not only optimizes the uniformity and stability of the perovskite scintillator film, but also promotes the development of perovskite in the field of EUV and X-ray multicolor curved surface imaging.
[0004] To achieve the above object, the application provides the following technical scheme:
[0005] An in-situ layer-by-layer growth method of a perovskite scintillator composite film, comprising the following steps:
[0006] FAPbI3@VmB1@polymer precursor solution, CsPbI3@VmB1@polymer precursor solution, CsPbBr3@VmB1@polymer precursor solution and Cs3Cu2I5@VmB1@polymer precursor solution are sequentially stacked on the surface of the substrate to prepare the perovskite scintillator composite film. Wherein, FA is formamidinium cation, and the molecular formula is: CH(NH2) 2+ .
[0007] Optionally, the polymers in the FAPbI3@VmB1@polymer precursor solution, CsPbI3@VmB1@polymer precursor solution, CsPbBr3@VmB1@polymer precursor solution, and Cs3Cu2I5@VmB1@polymer precursor solution are all selected from at least one of polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), and polyvinylidene fluoride (PVDF).
[0008] Optionally, the volume ratio of the FAPbI3@VmB1@polymer precursor solution, CsPbI3@VmB1@polymer precursor solution, CsPbBr3@VmB1@polymer precursor solution and Cs3Cu2I5@VmB1@polymer precursor solution is 1:1:1:1.
[0009] Optionally, the preparation process of the FAPbI3@VmB1@polymer precursor solution is as follows:
[0010] The polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain mixture 1;
[0011] FAI, PbI2, vitamin B1 (VmB1) powder and polar solvent are mixed and heated and stirred 2. Then, the mixture is added to the mixture 1 and heated and stirred 3 to obtain the FAPbI3@VmB1@polymer precursor solution.
[0012] Optionally, the preparation process of the CsPbI3@VmB1@polymer precursor solution is as follows:
[0013] The polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain the mixture 2;
[0014] CsI, PbI2, vitamin B1 (VmB1) powder and polar solvent are mixed and heated and stirred 2. Then, the mixture is added to the mixture 2 and heated and stirred 3 to obtain the CsPbI3@VmB1@polymer precursor solution.
[0015] Furthermore, the ratio of the CsI, PbI2, VmB1 powder to the polar solvent is 0.75 mmol: 0.5 mmol: 0.188 mmol: 2 mL.
[0016] Optionally, the preparation process of the CsPbBr3@VmB1@polymer precursor solution is as follows:
[0017] The polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain the mixture 3;
[0018] CsBr, PbBr2, vitamin B1 (VmB1) powder and polar solvent are mixed and heated and stirred for 2. Then, the mixture is added to the mixture and heated and stirred for 3 to obtain the CsPbBr3@VmB1@polymer precursor solution.
[0019] Furthermore, the ratio of the CsBr, PbBr2, VmB1 powders to the polar solvent is 0.75 mmol: 0.5 mmol: 0.188 mmol: 2 mL.
[0020] Optionally, the preparation process of the Cs3Cu2I5@VmB1@polymer precursor solution is as follows:
[0021] The polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain the mixture 4;
[0022] CsI, CuI, vitamin B1 (VmB1) powder and polar solvent are mixed and heated and stirred 2. Then, the mixture is added to the mixture 4 and heated and stirred 3 to obtain the Cs3Cu2I5@VmB1@polymer precursor solution.
[0023] Furthermore, the ratio of the CsI, CuI, VmB1 powder and the polar solvent is: 0.75 mmol: 0.5 mmol: 0.188 mmol: 2 mL.
[0024] Furthermore, the conditions for heating and stirring 1 are: heating temperature of 80–130°C; time of 2–60 min; stirring rate of 1600 r / min; and / or,
[0025] The conditions for heating and stirring 1 are: heating temperature of 80-130℃; time of 1-3 hours; stirring rate of 1600 r / min; and / or,
[0026] The conditions for heating and stirring 1 are as follows: heating temperature is 100-120℃; stirring speed is 1600r / min.
[0027] Furthermore, the ratio of the polymer solid powder to the polar solvent is 1g:3-5mL.
[0028] Furthermore, the polar solvent is N,N-dimethylformamide (DMF) or dimethyl sulfoxide solution (DMSO).
[0029] Optionally, the lamination process includes spin coating and annealing.
[0030] Furthermore, the spin coating conditions are: spin coating at a speed of 2000 r / min for 10 s.
[0031] Furthermore, the annealing conditions are as follows: annealing at 80-130℃ for 2-60 minutes.
[0032] A perovskite scintillator composite thin film was prepared by the above-described preparation method.
[0033] Applications of the aforementioned perovskite scintillator composite films in EUV and X-ray multicolor imaging.
[0034] Optionally, the response wavelength of the perovskite scintillator composite film in EUV and X-ray multicolor imaging is 0.02–13.5 nm.
[0035] Compared with the prior art, the present invention has the following advantages and technical effects:
[0036] This invention proposes an in-situ stacked growth method for perovskite scintillator composite films. Leveraging the strong interaction between perovskite nanocrystals and the polymer matrix, perovskite nanocrystal clustering is effectively suppressed, significantly improving the uniformity and stability of the perovskite scintillator film. Furthermore, this strategy is applicable to perovskite scintillator films with responses across various EUV to X-ray bands. Under EUV to X-ray excitation, perovskite scintillator films with different band responses exhibit different luminescence intensities and colors. By heterogeneously stacking perovskite scintillator films with different band responses and combining them with an imaging system, high-resolution multicolor images are achieved. The perovskite scintillator composite films prepared by this method demonstrate significant application advantages in EUV and X-ray multicolor surface imaging. Attached Figure Description
[0037] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:
[0038] Figure 1 This is a flowchart of the in-situ stacked growth method of the perovskite scintillator composite thin film of the present invention;
[0039] Figure 2 The UV-Vis absorption spectra and photoluminescence spectra under UV excitation of the perovskite scintillator films grown in situ under different systems in Examples 1-12 are shown.
[0040] Figure 3 Color coordinate diagrams of perovskite scintillator films grown in situ under different systems in Examples 1-12;
[0041] Figure 4 The ternary phase diagram for the photostability, thermal stability and air stability of the Cs3Cu2I5@VmB1@PVA perovskite scintillator film prepared in Example 1 is shown.
[0042] Figure 5 The radiative emission spectra of perovskite scintillator films in different systems;
[0043] Figure 6 Spatial resolution diagram of Cs3Cu2I5@VmB1@VA perovskite scintillator thin film;
[0044] Figure 7 This is a schematic diagram illustrating the application of the perovskite scintillator composite film grown in situ in Example 13 in the field of X-ray multicolor imaging.
[0045] Figure 8 Imaging images of Cs3Cu2I5@VmB1@PVA and FAPbI3@VmB1@PVA perovskite scintillator films under X-ray excitation at different energies;
[0046] Figure 9 The results of multicolor surface imaging of the perovskite scintillator composite thin film grown in situ under different energy X-ray irradiation in Example 13 are shown.
[0047] Figure 10 SEM images of the scintillator films prepared in Examples 1-4 and the film prepared in Comparative Example 1 are shown; where i is Cs3Cu2I5@PVA, ii is CsPbBr3@PVA, iii is CsPbI3@PVA, iv is FAPbI3@PVA, v is Cs3Cu2I5@VmB1@PVA, ui is CsPbBr3@VmB1@PVA, vi is CsPbI3@VmB1@PVA, and svii is FAPbI3@VmB1@PVA.
[0048] Figure 11 The graph shows a comparison of the fluorescence efficiency (left) and lifetime (right) of the scintillator films prepared in Examples 1-4 and the film prepared in Comparative Example 1. Detailed Implementation
[0049] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0050] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0051] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0052] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be obvious to those skilled in the art. This specification and embodiments are merely exemplary.
[0053] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0054] This invention discloses an in-situ stacked growth method for perovskite scintillator thin films, as well as its products and applications in EUV and X-ray multicolor surface imaging. The perovskite scintillator thin films prepared by the method of this invention improve the uniformity and stability of the perovskite scintillator while ensuring its excellent optical properties.
[0055] like Figure 1 As shown, the preparation of the in-situ stacked perovskite scintillator composite film consists of five stages. In the first stage, the polymer powder is dissolved in DMF / DMSO solvent after heating to form a colloidal solution. In the second stage, AX (FAI, CsI, CsBr) and BX (CuI) / BX2 (PbBr2, PbI2) are dissolved in DMF / DMSO solvent and then added to the colloidal solution. In the third stage, VmB1 powder is fully dissolved in DMF / DMSO solvent and added to the colloidal solution, and a uniformly dispersed precursor solution is obtained by heating and stirring. The fourth stage is the pre-curing stage of the perovskite scintillator film, in which the perovskite scintillator film is pre-cured during spin coating to form nanocrystal clusters. In the fifth stage, the pre-cured film is placed on a hot plate for heating and annealing, and the perovskite scintillator composite film is grown in situ on the substrate.
[0056] This invention discloses an in-situ stacking growth method for perovskite scintillator composite thin films, comprising the following steps:
[0057] (1) Polymer solution preparation: Mix polymer solid powder and polar solvent, heat and stir evenly to dissolve, and obtain a mixture;
[0058] The polymer powder is at least one of PVA, PMMA and PVDF;
[0059] The polar solvent is DMF or DMSO;
[0060] (2) Preparation of perovskite precursor solution: Dissolve AX powder, BX / BX2 powder and VmB1 powder in a polar solvent, and then add them to the mixture obtained in step (1) (i.e. the dissolved polymer solution) and heat and stir until there is no precipitate.
[0061] In the AX powder, A is Cs or FA, and X is Br or I;
[0062] In BX powder, B is Cu and X is I; or in BX2 powder, B is Pb and X is Br or I.
[0063] The polar solvent is DMF or DMSO;
[0064] When AX powder is FAI and BX2 powder is PbI2, the obtained product is FAPbI3@VmB1@polymer precursor solution;
[0065] When AX powder is CsI and BX2 powder is PbI2, the obtained product is CsPbI3@VmB1@polymer precursor solution;
[0066] When AX powder is CsBr and BX2 powder is PbBr2, the obtained product is a CsPbBr3@VmB1@polymer precursor solution.
[0067] When AX powder is CsI and BX powder is CuI, the obtained product is Cs3Cu2I5@VmB1@polymer precursor solution;
[0068] (3) Preparation of perovskite scintillator film: The perovskite precursor solution was coated on the substrate to form a film, and then annealed to obtain the perovskite scintillator film grown in situ.
[0069] (4) According to step (3), the above four precursor solutions are stacked sequentially on the substrate, so that the four perovskite scintillator films are stacked and grown in situ to obtain perovskite scintillator composite films with characteristic responses to EUV and X-rays of different energies.
[0070] In some optional embodiments, the ratio of polymer solid powder to polar solvent used in preparing the polymer solution is 1 g: 3-5 mL; the required dissolution temperature is 80-130 °C; the time is 2-60 min; and the stirring rate is 1600 r / min.
[0071] In some optional embodiments, when preparing the perovskite precursor solution, the ratio of AX, BX / BX2, VmB1, and the polar solvent is 0.75 mmol: 0.5 mmol: 0.188 mmol: 2 mL. Here, BX / BX2 represents one of these components.
[0072] In some optional embodiments, when preparing the perovskite precursor solution, the heating and stirring temperature is 80-130°C, the time is 1-3 hours, and the stirring rate is 1600 r / min.
[0073] In some optional embodiments, the preparation process of the perovskite scintillator thin film in step (3) is as follows:
[0074] The perovskite precursor solution was dropped onto the substrate surface;
[0075] Spin-coating at 2000 r / min for 10 s;
[0076] The annealing temperature is 80-130℃, and the time is 2-60 minutes.
[0077] This invention discloses a perovskite scintillator composite film prepared by the above-described in-situ stacked growth method.
[0078] This invention also discloses the application of perovskite scintillator composite films in EUV and X-ray multicolor surface imaging.
[0079] This invention utilizes heterogeneous stacking to prepare perovskite scintillator composite films with different energy responses, which can achieve EUV and X-ray multicolor surface imaging; the perovskite scintillator composite films have a response wavelength range of 0.02–13.5 nm in EUV and X-ray multicolor surface imaging.
[0080] The technical principle of this invention is as follows:
[0081] The perovskite scintillator composite film disclosed in this invention allows cations in the perovskite to act as Lewis acids and combine with Lewis base functional groups in the polymer matrix, forming Lewis acid-base pairs and generating interaction forces. During in-situ growth, the strong interaction forces between the polymer matrix and the perovskite nanocrystals effectively promote the uniform distribution of perovskite nanocrystals within the polymer matrix, thereby suppressing luminescence quenching induced by perovskite nanocrystal clusters. Therefore, the perovskite scintillator composite film prepared by the in-situ multilayer growth strategy of this invention exhibits excellent stability and uniformity.
[0082] Furthermore, during in-situ growth, the polymer matrix tightly encapsulates the perovskite nanocrystals; the outer polymer matrix exhibits excellent UV resistance, light resistance, and heat resistance, effectively preventing external environmental erosion of the internal perovskite nanocrystals. Therefore, the in-situ multilayered perovskite scintillator film demonstrates good photostability, airtightness, and thermal stability.
[0083] Unless otherwise specified, "room temperature" in this invention refers to 20-30℃.
[0084] All raw materials used in this invention were purchased from the market.
[0085] The technical solution of the present invention will be further illustrated by the following embodiments.
[0086] Example 1
[0087] A method for preparing a perovskite scintillator composite thin film, the specific steps of which are as follows:
[0088] I. Synthesis of Cs3Cu2I5@PVA@VmB1 precursor solution:
[0089] (1) In a glove box under nitrogen atmosphere, pour 1g of PVA polymer solid powder and 5mL of DMF solvent into a 40mL glass bottle and place a magnetic spool in it; place the mixed solution on a heating plate, set the temperature of the heating plate to 120℃, adjust the rotation speed to 1600r / min, heat and stir for 30min until a transparent solution is formed, and obtain a PVA / DMF polymer solution.
[0090] (2) In a glove box under nitrogen atmosphere, pour 0.75 mmol CsI, 0.5 mmol CuI, 0.188 mmol VmB1 and 2 mL LDM solvent into a 40 mL glass bottle and place a magnetic stir bar in it; place the mixed solution on a heating plate, set the temperature of the heating plate to 100 °C, adjust the speed to 1600 r / min, heat and stir for 3 h until the powder is completely dissolved;
[0091] (3) Add the solution obtained in step (2) to the PVA / DMF polymer solution prepared in step (1), filter it with a filter with a pore size of 0.22 μm, and add a magnetic particle; place the above solution on a heating plate, set the temperature of the heating plate to 120 °C, the stirring rate to 1600 r / min, heat and stir overnight to obtain a perovskite polymer precursor solution.
[0092] II. Preparation of Cs3Cu2I5@PVA@VmB1 scintillator thin films:
[0093] (1) Take 2 mL of perovskite polymer precursor solution and place it in a 5 mL glass bottle. Heat and stir at 100 °C for 10 min to disperse it evenly and obtain a mixture.
[0094] (2) Clean the quartz glass with acetone, isopropanol and deionized water in sequence using ultrasonic cleaning. After cleaning, blow it dry with an air gun to ensure that there is no dust or other contaminants on the surface of the quartz glass substrate.
[0095] (3) Use a micropipette to spin coat the obtained 75 μL perovskite polymer precursor solution onto a quartz glass substrate. Fix the glass substrate on a spin coater and spin coat at a speed of 2000 r / min for 10 s.
[0096] (4) Place the spin-coated wet film on a heating plate, set the heating plate temperature to 90℃, and anneal for 10 min to promote the in-situ crystallization of Cs3Cu2I5 nanocrystals in the PVA matrix and obtain the in-situ grown perovskite scintillator film (Cs3Cu2I5@VmB1@PVA).
[0097] Example 2
[0098] A method for preparing a perovskite scintillator thin film differs from Example 1 only in that “CsI” is replaced with an equimolar amount of “CsBr” and “CuI” is replaced with an equimolar amount of “PbBr2”, while the rest is the same as in Example 1 (CsPbBr3@VmB1@PVA).
[0099] Example 3
[0100] A method for preparing a perovskite scintillator thin film differs from Example 1 only in that “CsI” is replaced with an equimolar amount of “FAI” and “CuI” is replaced with an equimolar amount of “PbI2”, while the rest is the same as in Example 1 (FAPbI3@VmB1@PVA).
[0101] Example 4
[0102] A method for preparing a perovskite scintillator thin film differs from Example 1 only in that "CuI" is replaced with an equimolar amount of "PbI2", while the rest is the same as in Example 1 (CsPbI3@VmB1@PVA).
[0103] Examples 5-8
[0104] A method for preparing a perovskite scintillator thin film (Cs3Cu2I5@VmB1@PMMA) differs from Examples 1-4 only in that “PVA” is replaced with an equimolar amount of “PMMA”, otherwise the same as Examples 1-4.
[0105] Examples 9-12
[0106] A method for preparing a perovskite scintillator thin film (Cs3Cu2I5@VmB1@PVDF) differs from Examples 1-4 only in that “PVA” is replaced with an equimolar amount of “PVDF”, otherwise the same as Examples 1-4.
[0107] Example 13
[0108] An in-situ stacked growth method for a perovskite scintillator composite film is disclosed. The specific process is as follows: Following the preparation process and conditions described in Examples 1-4, films are sequentially prepared and stacked according to the order of FAPbI3@VmB1@PVA, CsPbI3@VmB1@PVA, CsPbBr3@VmB1@PVA, and Cs3Cu2I5@VmB1@PVA to ultimately obtain the perovskite scintillator composite film. Specifically, a FAPbI3@VmB1@PVA precursor solution is first spin-coated onto a substrate, followed by annealing to obtain a FAPbI3@VmB1@PVA scintillator film. Then, the next precursor solution is spin-coated onto the FAPbI3@VmB1@PVA scintillator film, followed by annealing, and this process is repeated in-situ to obtain the perovskite scintillator composite film.
[0109] Comparative Example 1
[0110] Compared to Examples 1-4, VmB1 was not added, but the other preparation processes and conditions were the same as in Examples 1-4.
[0111] The thin films prepared in Comparative Example 1 were: Cs3Cu2I5@PVA, CsPbBr3@PVA, FAPbI3@PVA, and CsPbI3@PVA.
[0112] Figure 2 Examples 1-12 show the UV-Vis absorption spectra and photoluminescence spectra of perovskite scintillator films grown in situ under different systems; [The remaining text appears to be a fragment and requires further context for accurate translation.] Figure 2 It can be seen that this in-situ growth strategy is applicable to a variety of perovskite-polymer systems; the perovskite scintillators prepared all exhibit unique characteristic emission.
[0113] Figure 3 The images show the color coordinates of the perovskite scintillator films grown in situ under different systems in Examples 1-12; Figure 3 It can be seen that the photoluminescence colors of the Cs3Cu2I5, CsPbBr3, CsPbI3 and FAPbI3 perovskite films grown in situ in the polymer are blue, green, red and red, respectively, covering the entire visible light region.
[0114] Figure 4The ternary phase diagram for the photostability, thermal stability, and air stability of the Cs3Cu2I5@VmB1@PVA perovskite scintillator film prepared in Example 1 is shown. Figure 4 It is evident that the in-situ grown perovskite quantum dot thin film obtained by this invention exhibits excellent photostability, airtightness, and thermal stability. Specifically, the Cs3Cu2I5@VmB1@PVA thin film retains 97% and 95% of its initial luminescence intensity after 720 hours of air and UV irradiation, respectively. Furthermore, the luminescence intensity of this film at 373K is maintained at 60% of its room temperature intensity.
[0115] Figure 5 The radiative emission spectra of perovskite scintillator films in different systems; by Figure 5 It is known that the light yields of the Cs3Cu2I5@VmB1@PVA, CsPbBr3@VmB1@PVA, CsPbI3@VmB1@PVA, and FAPbI3@VmB1@PVA scintillator films obtained in this invention reach 55521 photons / MeV, 9688 photons / MeV, 2376 photons / MeV, and 2283 photons / MeV, respectively. Among them, the light yield of Cs3Cu2I5@VmB1@PVA is comparable to that of commercially available CsI:TI scintillators (produced by Shanghai Shuojie Crystal Materials Co., Ltd., where the manufacturer states the light yield of this scintillator as 56000 photons / MeV, but testing shows it to be 54000 photons / MeV); Bi4Ge3O 12 Purchased from Henan Nuobadi Materials Technology Co., Ltd.
[0116] Figure 6 Spatial resolution image of Cs3Cu2I5@VmB1@PVA perovskite scintillator film; from Figure 6 It can be seen that the Cs3Cu2I5@VmB1@PVA scintillator film obtained in this invention exhibits a thickness of 14 lp mm. -1 High spatial resolution.
[0117] Figure 7 This is a schematic diagram illustrating the application of the in-situ multilayered perovskite scintillator composite film of Example 13 in X-ray multicolor imaging; Figure 7 It is known that in X-ray multicolor imaging applications, four layers of perovskite scintillators are stacked sequentially in the order of FAPbI3@VmB1@PVA, CsPbI3@VmB1@PVA, CsPbBr3@VmB1@PVA, and Cs3Cu2I5@VmB1@PVA. Under EUV and X-ray excitation at different energies, the four perovskite scintillator films (i.e., perovskite scintillator composite films) exhibit different sensitivities and characteristic emissions. The characteristic emissions of the four films are recorded by a fiber optic spectrometer and camera, thereby enabling energy-responsive multispectral detection and multicolor surface imaging.
[0118] Figure 8 Imaging images of Cs3Cu2I5@VmB1@PVA and FAPbI3@VmB1@PVA perovskite scintillator films under X-ray excitation at different energies; by Figure 8 It is known that the FAPbI3@VmB1@PVA perovskite scintillator film can obtain more image information of skeletons (low-density objects) under low-energy irradiation. Conversely, the Cs3Cu2I5@VmB1@PVA perovskite scintillator film can obtain more image information of metals (high-density objects) under high-energy irradiation.
[0119] The perovskite scintillator films grown in situ using Examples 1-4 were selected for X-ray multicolor surface imaging applications. The specific steps are as follows:
[0120] (1) The perovskite scintillator films obtained in Examples 1-4 were sequentially stacked and grown in situ in the order of FAPbI3@VmB1@PVA, CsPbI3@VmB1@PVA, CsPbBr3@VmB1@PVA, and Cs3Cu2I5@VmB1@PVA. Then, the films and the target imaging object were respectively fixed using sample holders to ensure they were on the same horizontal plane.
[0121] (2) After the EUV light source (13.5 nm) and X-ray light sources of different wavelengths (0.0207 nm to 0.124 nm) penetrate the imaging object of the target, they are irradiated onto the stacked perovskite scintillator composite film. The scintillator composite film converts EUV and X-ray light into visible light in the blue to near-infrared band.
[0122] (3) The converted visible light is reflected by the silver-plated mirror and collected by the CCD camera.
[0123] (4) After exposure, the internal semiconductor of the CCD camera generates electron-hole pairs, producing an electrical signal. After amplification and processing, the signal is converted into a voltage signal output, and then converted into a digital signal by an analog-to-digital converter. This ultimately achieves four-channel multicolor imaging.
[0124] Figure 9 The results of multicolor surface imaging of the perovskite scintillator composite thin film grown in situ under different energy X-ray irradiation are shown in Example 13. Figure 9 It is known that the scintillator composite film based on four-layer perovskite heterostructure stack can effectively meet the application requirements of multicolor curved surface imaging. That is, the present invention applies the obtained in-situ stacked perovskite scintillator film to the field of X-ray imaging, realizing four-channel X-ray multicolor curved surface imaging.
[0125] Figure 10SEM images of the scintillator films prepared in Examples 1-4 and the film prepared in Comparative Example 1 are shown. Specifically, i-iv represent the film prepared in Comparative Example 1 without VmB1, and v-viii represent the scintillator films prepared in Examples 1-4 with VmB1. Specifically, i is Cs3Cu2I5@PVA, ii is CsPbBr3@PVA, iii is CsPbI3@PVA, iv is FAPbI3@PVA, v is Cs3Cu2I5@VmB1@PVA, ui is CsPbBr3@VmB1@PVA, vi is CsPbI3@VmB1@PVA, and vii is FAPbI3@VmB1@PVA. As can be seen from the images, the scintillator film prepared with VmB1 as a raw material has a larger scintillator size and more regular crystal lattice growth.
[0126] Figure 11 The graph shows a comparison of the fluorescence efficiency (left) and lifetime (right) of the scintillator films prepared in Examples 1-4 and the film prepared in Comparative Example 1. As can be seen from the graph, compared to Comparative Example 1, the scintillator films prepared in Examples 1-4 of this invention with the addition of VmB1 exhibit superior fluorescence intensity and lifetime; that is, the addition of VmB1 to the raw materials can significantly improve fluorescence intensity and lifetime.
[0127] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for in-situ stacked growth of perovskite scintillator composite thin films, characterized in that, Includes the following steps: The perovskite scintillator composite thin film was prepared by sequentially stacking FAPbI3@VmB1@polymer precursor solution, CsPbI3@VmB1@polymer precursor solution, CsPbBr3@VmB1@polymer precursor solution and Cs3Cu2I5@VmB1@polymer precursor solution on the substrate surface after each film was prepared.
2. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 1, characterized in that, The polymers in the FAPbI3@VmB1@polymer precursor solution, CsPbI3@VmB1@polymer precursor solution, CsPbBr3@VmB1@polymer precursor solution, and Cs3Cu2I5@VmB1@polymer precursor solution are all selected from at least one of polyvinyl alcohol, polymethyl methacrylate, and polyvinylidene fluoride.
3. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 1, characterized in that, The volume ratio of the FAPbI3@VmB1@ polymer precursor solution, CsPbI3@VmB1@ polymer precursor solution, CsPbBr3@VmB1@ polymer precursor solution, and Cs3Cu2I5@VmB1@ polymer precursor solution is 1:1:1:
1.
4. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 1, characterized in that, The preparation process of the FAPbI3@VmB1@polymer precursor solution is as follows: polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain mixture 1; FAI, PbI2, VmB1 powder and polar solvent are mixed and heated and stirred 2, and then added to the mixture 1 and heated and stirred 3 to obtain the FAPbI3@VmB1@polymer precursor solution; And / or, The preparation process of the CsPbI3@VmB1@polymer precursor solution is as follows: polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain a mixture 2; CsI, PbI2, VmB1 powder and polar solvent are mixed and heated and stirred 2, and then added to the mixture 2 and heated and stirred 3 to obtain the CsPbI3@VmB1@polymer precursor solution; And / or, The preparation process of the CsPbBr3@VmB1@ polymer precursor solution is as follows: polymer solid powder and a polar solvent are mixed and heated and stirred for 1 to obtain a mixture 3; CsBr, PbBr2, VmB1 powders and a polar solvent are mixed and heated and stirred for 2, then added to the mixture 3 and heated and stirred for 3 to obtain the CsPbBr3@VmB1@ polymer precursor solution; and / or, The preparation process of the Cs3Cu2I5@VmB1@ polymer precursor solution is as follows: the polymer solid powder and polar solvent are mixed and heated and stirred 1 to obtain a mixture 4; the CsI, CuI, VmB1 powder and polar solvent are mixed and heated and stirred 2, and then added to the mixture 4 and heated and stirred 3 to obtain the Cs3Cu2I5@VmB1@ polymer precursor solution.
5. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 4, characterized in that, The ratios of the amounts of FAI, PbI2, VmB1 powder and polar solvent, the ratios of the amounts of CsI, PbI2, VmB1 powder and polar solvent, the ratios of the amounts of CsBr, PbBr2, VmB1 powder and polar solvent, and the ratios of the amounts of CsI, CuI, VmB1 powder and polar solvent are all 0.75 mmol: 0.5 mmol: 0.188 mmol: 2 mL.
6. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 4, characterized in that, The conditions for heating and stirring 1 are: heating temperature of 80–130°C; time of 2–60 min; stirring rate of 1600 r / min; and / or, The conditions for heating and stirring 2 are: heating temperature of 80-130℃; time of 1-3 hours; stirring rate of 1600 r / min; and / or, The conditions for heating and stirring 3 are as follows: heating temperature is 100-120℃; stirring speed is 1600r / min.
7. The in-situ stacked growth method of a perovskite scintillator composite thin film according to claim 1, characterized in that, Each precursor solution film preparation process includes spin coating and annealing steps; The spin coating conditions are: spin coating at a speed of 2000 r / min for 10 s; The annealing conditions are as follows: annealing at 80-130℃ for 2-60 minutes.
8. A perovskite scintillator composite thin film, characterized in that, It is prepared by the in-situ laminated growth method according to any one of claims 1-7.
9. The application of the perovskite scintillator composite thin film as described in claim 8 in EUV and X-ray multicolor imaging.
10. The application of the perovskite scintillator composite thin film according to claim 9 in EUV and X-ray multicolor imaging, characterized in that, The perovskite scintillator composite film has a response wavelength of 0.02–13.5 nm in EUV and X-ray multicolor imaging.