Preparation And Properties Of High-performance CsPbBr₃ Perovskite Scintillator Materials

X-ray is a common type of high-energy radiation.Due to its high photon energy and strong penetrability,X-rays are widely used in the fields of medical diagnosis,radiotherapy,industrial flaw detection,safety inspection,aerospace navigation and scientific research materials analysis.Among them,the scintillator,as a conversion device that converts X-ray photon signals into electrical signals,is the core component of X-ray detectors,and it is also the core scientific and technological research technology facing the country.Generally speaking,scintillators are composed of high-density heavy elements.However,traditional scintillators are generally large-scale inorganic crystals that can only grow in a high-temperature environment,which greatly increases production costs and preparation difficulties.In addition,due to the low efficiency or the limitation of the afterglow effect,the luminescence of most traditional scintillators is difficult to adjust in the visible spectrum.As the performance of traditional scintillators reaches the limit,and the requirements for x-ray imaging and detection technology are getting higher and higher,therefore,the exploration and research of new scintillators has become an urgent problem.Halide perovskite has become an excellent luminescent material due to its high photoluminescence quantum yield（PLQY）,easily coordinated luminescence color and simple manufacturing process.At the same time,halide perovskites are particularly equipped with high atomic number（Z）and high-quality elements,such as Pb and Br atoms.For X-ray absorption,the absorption cross section increases with the increase of Z4.It also means that compared with the usual scintillator material halide perovskite has a good ionizing radiation absorption capacity.In addition,the halide perovskite also has the characteristics of fast decay time and low detection limit,making it outstanding in X-ray detection and imaging capabilities.It is also due to these excellent properties that it has recently been considered the most promising scintillating material.Radiography and other fields.However,the all-inorganic perovskite nanocrystalline material will produce a large number of intrinsic defects during the synthesis process.The existence of intrinsic defects makes its stability in the X-ray environment and other optical properties poor.Therefore,in order to realize its commercial application,we still need to further design its structure,design and synthesize a scintillator with X-ray imaging performance.The specific content is:（1）First,based on the all-inorganic perovskite（CsPbBr3）prepared by the solution method,a wet chemical annealing method with a relatively easy-to-control process is used to improve the crystal structure.The defect content of the obtained NCs is obviously reduced and the structure is more complete.The annealed samples have higher thermal stability,light stability and water stability.The prepared CsPbBr3 NCs was encapsulated into a transparent scintillator using PMMA.Preliminarily explore the application of perovskite materials as scintillator materials.（2）Organic materials encapsulate perovskite nanocrystals as scintillator materials,but its transparency and uniformity are difficult to guarantee.At the same time,the environmental weather resistance of organic materials is not excellent.Therefore,Eu³⁺ion doped in situ grown in our transparent amorphous matrix,the mixed CsPbBr3 quantum dots form a translucent glass ceramic（GC）scintillator,and the glass phase is used as the encapsulation of the perovskite quantum dot emitter.Prepared a more uniform transparent perovskite ceramic scintillator,creating the recording resolution of the perovskite type scintillator,exceeding the typical commercial Cs I（TI）scintillator with 10.0 pl/mm.In addition,we also explored its Stability of long-term use at low doses.（3）On the basis of the former,we further discussed the possibility of long-term use of translucent glass ceramic（GC）scintillators formed by Lu³⁺ion-doped CsPbBr3 quantum dots under high doses.Discuss and study the mechanism of crystal damage caused by high-energy radiation.When judging that radiation damage is inevitable under high-dose radiation,a special thermal annealing repair method is designed to extend and enhance the service life of the scintillator.Thus,a high-performance X-ray scintillator is prepared.