Tunable electronic band structure, luminescence properties and thermostability of (Gd1-xLax)2Si2O7:Ce scintillator by adjusting La/Gd ratio*

Mixed crystal strategy is an effective approach of improving the luminescence properties of optical materials and has been adopted widely in many systems. In this paper, the La-mixed Gd2Si2O7:Ce polycrystalline samples were successfully synthesized by a sol-gel method. The crystal structure and luminescence properties were confirmed and discussed by XRD, UV-Vis luminescence spectra, and XEL, respectively. The vacuum ultraviolet excitation spectra and thermoluminescence glow curves were also systematically investigated and discussed at varied temperature. A combination of the first-principles calculations and optical characterization experiments was employed to study the electronic band structure of host material, revealing that the band gap is narrowed and the 5d1 level of Ce3+ shifts to higher energy as the La content increases. The luminescence thermo-stability and activation energy were also measured and calculated. It indicates that thermo-stability is strongly dependent on the La concentration. An effective approach is developed to tune the electronic band structure, luminescence properties and thermostability of (Gd1-xLax)2Si2O7:Ce scintillator by adjusting La/Gd ratio. 0 2020 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

Automated summary

The mixed crystal strategy of improving luminescence properties has been widely adopted in many systems. In this study, La-mixed Gd2Si2O7:Ce polycrystalline samples were successfully synthesized and their crystal structure and luminescence properties were confirmed and discussed. It was found that the thermo-stability of luminescence is strongly dependent on the La concentration.