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CN-117586767-B - Multistage laminated scintillator based on perovskite quantum dot wave-shifting effect and preparation method thereof

CN117586767BCN 117586767 BCN117586767 BCN 117586767BCN-117586767-B

Abstract

The invention relates to the field of radiation detection, and provides a multistage laminated scintillator based on a perovskite quantum dot wave-shifting effect, which aims to solve the problem that the external quantum yield of a scintillator is reduced due to the self-absorption effect in the crystal of the existing ultrafast scintillator in contradictory relation between the luminous efficiency and the detection efficiency, and comprises a scintillator and perovskite quantum dots, wherein the scintillator is N layers, the N layers of the scintillator are taken as ray absorption layers, the perovskite quantum dots are N+1 layers, the N+1 layers of the perovskite quantum dots are taken as wavelength conversion layers, the N+1 layers of the perovskite quantum dots and the N layers of the scintillator are sequentially and alternately stacked to form the multistage laminated scintillator, the outer surface of the multistage laminated scintillator is provided with a transparent organic polymer packaging layer, the self-absorption of photons in the scintillator can be effectively reduced, the overall external quantum yield is improved, and the problem that the luminous efficiency and the detection efficiency of the scintillator are difficult to be considered is solved.

Inventors

  • WANG FANGBAO
  • HE SHIYI
  • CHEN LIANG
  • LI YANG
  • ZHANG SILONG
  • OUYANG XIAOPING

Assignees

  • 西北核技术研究所

Dates

Publication Date
20260505
Application Date
20231102

Claims (8)

  1. 1. Multistage stromatolite scintillator based on perovskite quantum dot shift effect, including scintillator (1) and perovskite quantum dot (2), its characterized in that: the scintillator (1) is N layers, the N layers of the scintillator (1) are taken as a ray absorption layer, the perovskite quantum dots (2) are N+1 layers, and the N+1 layers of the perovskite quantum dots (2) are taken as a wavelength conversion layer; the N+1 layer perovskite quantum dots (2) and the N layer scintillators (1) are sequentially and alternately stacked to form a multi-layer scintillator; the outer surface of the multilayer scintillator is provided with a transparent organic polymer packaging layer (3); The scintillator (1) is any one of ZnO, gaN, cuI or a doping modified scintillator material taking any one of ZnO, gaN, cuI as a substrate; The perovskite quantum dots (2) are CsPbX 3 quantum dots, wherein X is Cl, br, I or a combination of any two of the above.
  2. 2. The multi-layered stacked scintillator based on the perovskite quantum dot shift effect according to claim 1, wherein the thickness of each layer of the scintillator (1) is 0.2mm-0.5mm.
  3. 3. The multi-level stacked scintillator based on the wave-shifting effect of perovskite quantum dots according to claim 2, wherein the thickness of each layer of perovskite quantum dots (2) is 200nm-400nm.
  4. 4. The multi-level stacked scintillator based on perovskite quantum dot wave-shifting effect as claimed in claim 3, wherein the encapsulation layer (3) is an epoxy resin seal layer.
  5. 5. The multi-level stacked scintillator based on perovskite quantum dot wave-shifting effect as claimed in claim 4, wherein the number of layers N of the scintillator (1) satisfies the following formula: Wherein I out is the intensity of emergent light, N is the number of layers of the scintillator (1), I represents the ith layer of the scintillator (1) from the radiation direction of rays, I a is the initial intensity of incident X rays, mu is the absorption coefficient of the scintillator (1) to the X rays, d is the thickness of each layer of the scintillator (1), a 4 is the transmission efficiency of converted light passing through each layer of the scintillator (1) and the perovskite quantum dots (2), and the converted light refers to light re-emitted after the perovskite quantum dots (2) absorb the light emitted by the scintillator (1).
  6. 6. The method for preparing the multi-stage laminated scintillator based on the perovskite quantum dot wave-shifting effect as claimed in any one of claims 1 to 5, which is characterized by comprising the following steps: Step one, polishing the surface of a crystal of a scintillator (1), and cleaning and drying the polished crystal of the scintillator (1); Adding the perovskite quantum dots (2) into an organic solution for dissolution and filtration, and then adding the organic solution into an organic ligand solution to form a precursor solution of the perovskite quantum dots (2); Uniformly spraying a precursor solution of the perovskite quantum dots (2) on the surface of the scintillator (1) by adopting a thin film electrostatic spraying mode, and then placing the sprayed scintillators (1) in a laminated manner to form a multi-layer scintillator (1); And fourthly, drying the multilayer scintillator (1) after lamination placement, and then placing the dried multilayer scintillator (1) in a transparent organic polymer packaging material for curing to finally form the multi-stage lamination scintillator based on the perovskite quantum dot wave-shifting effect.
  7. 7. The method for preparing the multi-stage laminated scintillator based on the perovskite quantum dot wave-shifting effect according to claim 6, wherein in the second step, the organic solution is a dimethylamide solvent; the organic ligand solution is dodecylbenzene sulfonic acid.
  8. 8. The method for preparing the multi-stage laminated scintillator based on the perovskite quantum dot wave-shifting effect, which is characterized in that in the third step, a thin film electrostatic spraying mode is adopted to spray the two sides of the first layer of scintillator (1), the other layers of scintillators (1) are sprayed on one side, and the spraying surfaces of the adjacent scintillators (1) are laminated with the non-spraying surfaces.

Description

Multistage laminated scintillator based on perovskite quantum dot wave-shifting effect and preparation method thereof Technical Field The invention relates to the field of radiation detection, in particular to a multi-stage laminated scintillator based on perovskite quantum dot wave-shifting effect and a preparation method thereof. Background Scintillators are one of the most widely used materials in nuclear radiation detection, and have the advantage of being difficult to replace in the fields of radiation imaging, transient pulse radiation measurement and the like. The luminous yield and decay time are important parameter indexes for measuring the performance of the scintillator material, and reflect the efficiency of the scintillator material for converting radiation into a detectable light signal and the response speed of the scintillator material to transient pulse radiation respectively, and the conventional scintillator material is generally faced with the trade-off between the luminous yield and the decay time, namely, the fast response scintillator, such as ZnO, gaN, cuI, and the like, and the luminous efficiency of the fast response scintillator is generally lower. One important reason for the low luminous efficiency of the scintillator is that the excitation spectrum and the absorption spectrum of the ultra-fast scintillator have a large overlapping area, so that light emitted by the absorption rays is absorbed by the scintillator in the process of transmitting to the outside, a serious self-absorption phenomenon is caused, and the external quantum yield of the scintillator is greatly reduced. The self-absorption degree of the scintillator can be reduced by reducing the thickness of the scintillator, but for high-energy rays, due to the strong penetrating capacity, a detection volume with enough thickness is needed to realize higher detection efficiency, so that the existing ultra-fast scintillator faces contradiction between external quantum efficiency and detection efficiency. How to effectively solve the contradictory relation between the luminous efficiency and the detection efficiency of the ultra-fast scintillator and improve the overall external quantum yield is the key for optimizing the ultra-fast scintillator. Disclosure of Invention The invention provides a multi-stage laminated scintillator based on perovskite quantum dot wave-shifting effect and a preparation method thereof, which are used for solving the problem that the luminous efficiency and the detection efficiency of the existing ultra-fast scintillator are difficult to be compatible. The design concept of the invention is that perovskite quantum dot materials are introduced into a scintillator material as interlayers or coatings to form a multi-stage laminated conversion structure, short wavelength light generated by radiation absorption of the scintillator is converted into long wavelength light through the wavelength conversion function of the perovskite, and self-absorption of photons in the scintillator can be effectively reduced, so that the overall external quantum yield is improved, and the contradiction relation between the luminous efficiency and the detection efficiency of the ultra-fast scintillator is effectively solved. In order to achieve the above purpose, the technical solution provided by the present invention is as follows: The multi-stage laminated scintillator based on the perovskite quantum dot wave-shifting effect comprises a scintillator and perovskite quantum dots, and is characterized in that: the scintillator is N layers, the N layers of scintillators are taken as ray absorption layers, the perovskite quantum dots are N+1 layers, and the N+1 layers of perovskite quantum dots are taken as wavelength conversion layers; the N+1 layers of perovskite quantum dots and the N layers of scintillators are sequentially and alternately stacked to form a plurality of layers of scintillators; the outer surface of the multilayer scintillator is provided with a transparent organic polymer packaging layer. Further, the scintillator is any one of ZnO, gaN, cuI or a ZnO, gaN, cuI-based doped modified scintillator material. Further, the thickness of the scintillator of each layer is 0.2mm-0.5mm. Further, the perovskite quantum dots are CsPbX 3 quantum dots, wherein X is Cl, br, I or any two of them in combination. Further, the thickness of each layer of perovskite quantum dots is 200nm-400nm. Further, the packaging layer is an epoxy resin sealing layer. Further, the number of layers N of the scintillator satisfies the following formula: Wherein I out is the intensity of emergent light, N is the number of layers of scintillators, I represents the ith layer of scintillators from the radiation direction of rays, I a is the initial intensity of incident X rays, mu is the absorption coefficient of the scintillators to the X rays, d is the thickness of each layer of scintillators, a 4 is the transmission efficiency of converte