X-ray Luminescence And Imaging Based On Copper Halide Scintillator

X-ray has irreplaceable advantages in scientific research,medical diagnosis,quality inspection,security and other fields because of its non-destructive penetration.Different ways of interaction between X-ray and matter produce different characteristic particles.Through the analysis of characteristic particles,the internal structure information of matter can be restored,which is the mechanism of X-ray detection.According to different detection strategies,X-ray detector can be classified to direct detector and indirect detector.The former directly detects the carrier changes after X-ray penetration,while the latter first converts high-energy x-ray photons into low-energy visible photons,and then detects or images the X-ray by photodiode or photodetector array.The traditional direct x-ray detector uses silicon,germanium,CdTe and other semiconductor materials as the energy conversion layers.Although it has certain advantages in sensitivity and response speed,it faces the problems of low X-ray absorption efficiency,thermal noise,leakage current and so on,and the preparation process is more complex and the cost is higher.Because of the energy conversion and re-detection process of the indirect detector,both the scintillation characteristics of the scintillator itself and the matching with the detector affect the detection quality,which requires higher optical properties of the scintillators.The current scintillator materials can not get a better balance in the cost and scintillation characteristics.An ideal scintillator should have the following characteristics:high X-ray stopping power,high light yield,fast scintillation response rate,high stability,free of self-absorption,and nontoxicity.In fact,no scintillator can fulfill all these requirements.However,the materials based on low dimensional copper halides show large Stokes shift,low self-absorption,short PL decay time,and environmental friendliness in the past fluorescence studies,which may be considered as a potential scintillator material.In this paper,the synthesis and preparation methods of high-quality copper halide materials are first studied,and then further the luminescence mechanism and photoluminescence characteristics are explored by monitoring the changes of photoluminescence spectra and time resolved photoluminescence spectra from low temperature to high temperature.Then,the scintillation characteristics are verified by experiments on the home-build system,and the experimental results show that both of them have high X-ray absorption efficiency,high light yield,low detection limit and short photoluminescence decay time.Through the panel and CT imaging experiments,the high spatial resolution and clear mage quality of scintillator film based on copper halide were realized,which confirmed the application potential of the material in industrial and medical detection.This paper also studies the benefits of flexible scintillator film based on copper halide on reducing the vignetting effect and non-uniform projection of the imaging system,and puts forward a solution to improve the quality of X-ray imaging based on.In this paper,the photoluminescence and scintillation performance of copper halides CsCu2I3 and Cs3Cu2I5 are studied in detail.A method for preparing high-quality scintillator thin films is proposed.Imaging and flexibility experiments are carried out.The crystal structure,optical properties and optical applications of CsCu2I3 and Cs3Cu2I5 are studied.This paper complements the research gap in this field,and provides a possible solution for the preparation of high-quality scintillator thin films in large area in the future,which is of great significance.