Properties of Charge Carrier Traps in Lu2O3:Tb,Hf Ceramic Storage Phosphors Observed by High-Pressure Spectroscopy and Photoconductivity

In this work, the kinetic study of charge carrier trapping processes, photocurrent excitation measurements, and high-pressure spectroscopy investigation of an optically stimulated luminescence (OSL) process in Lu2O3:Tb,Hf ceramics are presented. The OSL process was experimentally and theoretically treated to explain the OSL mechanism and kinetics. The obtained results allowed to propose an energetic structure of the system and a theoretical model that explains the charge exchange between Hf4+ and Tb3+ (upon charging the system). It was shown that the OSL took place via the conduction band and the depths of Hf traps were determined for the thermal (1.36 eV) and optical (2.95 eV) release and the significant difference between these two values was fully justified.