Preparation And Characterization Of All-Inorganic Halide Perovskite Scintillation Materials

Scintillator,as the core component of X-ray detection and imaging system,has been widely used in the fields of nuclear medicine imaging,safety detection,industrial nondestructive inspection,high energy physics and so on.With the development of X-ray detection technology,people are pursuing environmentally friendly scintillation conversion panel with high light yield,fast decay time,high stability and high spatial resolution.Traditional scintillation crystals have many problems such as complex preparation conditions,high cost and low imaging resolution.In recent years,all-inorganic halide perovskite materials have become a promising new scintillation material due to their advantages such as continuously adjustable luminescence wavelength,fast dacay time,low detection limit,strong X-ray cutoff ability.Among them,Cs Pb Br₃ scintillation film,which has been studied the most,has high spatial resolution of X-ray imaging,but seriously self-absorption and weak stability and the toxic element lead,limit its further development.Therefore,lead-free perovskite has gradually become the mainstream trend of research.The emerging cupric halide perovskite has high light yield,zero self-absorption,non-toxic and shows excellent scintillation and luminescence characteristics.Horizontal light dispersion of planar scintillation films usually results in lower imaging resolution.Based on the above questions,in this paper,the preparation of a new type of all-inorganic halide perovskite Cs₃Cu₂I₅ and Cs Cu₂I₃ powder,and combined with Polydimethylsiloxane（PDMS）template,A pixelated X-ray scintillation conversion panel based on Cs₃Cu₂I₅ and Cs Cu₂I₃ was designed and prepared.The scintillation and imaging performance of the new scintillation conversion panel were studied in depth,the results of the study are as following:1.Cs₃Cu₂I₅ powder with PLQY up to 94.23%was efficiently prepared by reverse-solvent method.After 100 days in the air,the luminous efficiency remained at 94%of the initial value.The light yield of the Cs₃Cu₂I₅ is up to 78,800 photons/Me V.Combined with the template assisted method and the negative pressure filling method,the pixelated Cs₃Cu₂I₅/PDMS array is prepared.The imaging spatial resolution was up to3.62 lp/mm,which is 2.66 times higher than that of the flat film（1.36 lp/mm）,and is close to the ultimate resolution of the TFT detector（4 lp/mm）.2.Cs Cu₂I₃ micron rod is prepared by reverse-solvent method,which shows fast fluorescence decay time（123 ns）,good stability,short afterglow and so on.The Cs Cu₂I₃ micron rod was filled into the PDMS template to obtain the Cs Cu₂I₃/PDMS array.Imaging tests of the spring capsule were performed under high-energy X-rays,and obtained a spatial resolution of 2.91 lp/mm.This work has a certain guiding significance for the design and preparation of scintillation conversion panel with fast dacay,good stability and high spatial resolution.