Defect Research in Cs2LiYCl6:Ce Crystal Scintillators

• Published in: Journal of electronic materials Vol. 52; no. 3; pp. 1958 - 1967
• Main Authors: Zhu, Mengqi, Wang, Biao, Jia, Xinhui, Zhang, Yutong, Li, Jing, Wang, Jiyang
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2023; Springer Nature B.V
• Subjects: Bridgman method; Carrier mobility; Cerium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cooling rate; Crack propagation; Crystal defects; Crystal growth; Density; Doppler effect; EFG (crystal growth); Electronics and Microelectronics; High temperature; Instrumentation; Materials Science; Optical and Electronic Materials; Original Research Article; Raw materials; Red shift; Scintillation counters; Solid State Physics; Spectra; Temperature distribution; Cs; Ce; trap-state density; morphology; LiYCl; radioluminescence spectra; scintillator; crystal growth; segregation
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-022-10147-2

As a promising material for dual γ -ray and neutron detection, Cs 2 LiYCl 6 :Ce (CLYC:Ce) has been increasingly studied and developed. In this work, CLYC:Ce is grown by two different growth methods, edge-defined film-fed growth (EFG) and the vertical Bridgman method. The phase segregation, macroscopic morphology, microscopic defects, trap-state density and radioluminescence spectra of CLYC:Ce are recorded and analyzed in detail. Because of the different raw material ratios, different second phases appear in the crystal growth process, which shows the phase segregation in the crystal. In the process of crystal growth, there are obvious cracks, bubbles, and inclusion and agglomeration phenomena in the crystal. We speculate that the reasons for these issues include inadequate mixing of the melt, the mismatch of temperature field and the excessive growth rate or excessive cooling rate. The high-quality CLYC:Ce has high carrier mobility (21.3390 cm 2 V −1  s −1 ) and ultra-low trap-state density (4.0681 × 10 8  cm −3 ). According to the radioluminescence spectra, only peaks in the range of 330–450 nm exist in the whole temperature range, corresponding to Ce 3+ component luminescence. With the increase in temperature, the emission peaks show a slight red-shift and the full width at half maximum (FWHM) generally shows an increasing trend. In the high-temperature region, the intensity of the main peak at 360 nm gradually decreases, while the intensity of the weak peak at 435 nm gradually increases.