Growth Process and Optical Properties of Cs2ZrCl6 Doped with Ce3+ and Li+ Crystals

Cs2ZrCl6 (CZC) has very promising scintillation properties in the application of gamma-ray spectroscopy. So far, undoped crystals of this composition have been studied, but the growth of the large-scale doped single crystals has not been reported so far. In this paper, a process improvement strategy is reported. Large-scale Cs2ZrCl6:Ce,Li (CZC:Ce,Li) single crystals with excellent energy resolution are obtained by appropriately adjusting the temperature gradient and growth rate. CZC:Ce,Li single crystals doped with 0.5, 1.5, and 3.0 mol % Ce3+ were grown by the Bridgman method. After the phase purity of the sample was determined by X-ray diffraction analysis, the crystal defects were determined by the energy-dispersive X-ray spectroscopy, and the crystal growth process was improved on this basis. The transmission spectrum confirmed the improvement of crystal quality. The energy resolution of CZC:Ce,Li crystals grown by the improved process is 4.3%, which confirmed that the improved process is conducive to the growth of bulk doped CZC single crystals, and hence, our results provide a basis for the growth of large-scale doped CZC single crystals.