Preparation And Performance Of Novel Scintillators Based On CsPbBr₃ Nanocrystals

Scintillation material is a kind of material that can absorb high energy ionizing radiation(?,?,?,X-ray,etc.)into ultraviolet or visible light energy conversion luminescent materials,plays an extremely important role in nuclear physics,atomic energy,nuclear medicine imaging,industrial detection,neutron detection,environmental monitoring,and other fields.With the rapid development of X-ray imaging and detection technology,the performance of traditional scintillators is difficult to meet the demand,so the exploration of new scintillators has become an urgent problem to be solved.In recent years,the halide perovskite quantum dot CsPbX₃(X=Br,Cl,I)has been regarded as the most promising new scintillation material due to its advantages such as fast attenuation,low detection limit,and color tunability,which has attracted researchers'wide attention.However,the stability of halide perovskite quantum dots is poor,and they are susceptible to environmental factors such as light and heat,which severely restrict their practical applications.Therefore,the development of halide perovskite quantum dot scintillators with excellent stability,high light yield,fast attenuation,and low cost has important academic significance and practical value.This article first summarizes the basic principles and performance requirements of scintillators,investigates and summarizes the research progress of scintillators at home and abroad in recent years.On this basis,taking CsPbBr₃ nanocrystals as the research object,the glass matrix is used to coat the nanocrystals,which effectively improves the stability of the halide perovskite nanocrystals.In addition,a new type of CsPbBr₃ nanocrystalline scintillation material coated with polystyrene and borosilicate glass was prepared,and its properties were characterized.(1)CsPbX₃(X=Br,Cl,I)quantum dots are used as a new wave-shifting agent,and the scintillation material2,5-diphenyloxazole(PPO)is dispersed in n-hexane to make the wavelength-tunable(red/Green/Blue)New organic liquid scintillator.Due to the efficient energy transfer effect between the CsPbBr₃ quantum dots and the scintillation material PPO,the radioluminescence(XEL)intensity of the scintillator under X-ray irradiation is improved.At the same time,in order to solve the problem of poor stability of CsPbBr₃ quantum dots in organic solvents,a new type of scintillator of polystyrene-encapsulated CsPbBr₃ quantum dots was prepared by thermal polymerization,and its scintillation performance was systematically characterized.(2)To solve the defects of polymers that are easy to age and not resistant to high temperature,a new type of scintillation material of CsPbBr₃ nanocrystalline encapsulated by borosilicate glass was prepared by the high-temperature melting method.The effects of heat treatment temperature and time on material properties were studied,the stability of CsPbBr₃ nanocrystals after packaging was tested,and the scintillation properties of the prepared new scintillation materials were systematically characterized.(3)In order to solve the problem that part of the X-ray energy absorbed by the glass matrix cannot be effectively transferred to the CsPbBr₃ nanocrystals,a new type of scintillation of CsPbBr₃ nanocrystals encapsulated by Ce³⁺doped borosilicate glass was prepared by introducing Ce³⁺into the borosilicate glass matrix.material.It is found that the introduction of Ce³⁺can effectively transfer the X-ray energy absorbed by the glass matrix to CsPbBr₃,thereby improving the XEL and quantum efficiency(QE)of glass-ceramics.At the same time,the optimal doping concentration of Ce³⁺was studied,and the performance changes of scintillation materials before and after doping were analyzed and compared.