AFTERGLOW AND THERMOLUMINESCENCE PROPERTIES OF LU2SIO5-CE SCINTILLATION CRYSTALS

The afterglow and thermoluminescence (TL) properties of several Ce3+ doped Lu2SiO5 crystals are reported. Both properties are caused by the presence of charge traps in the crystals. At least six different glow peaks are observed in the TL glow curve. Each is related to a specific charge trap. The parameters for these charge traps, such as the trap depth and the frequency factor, were obtained from first-order kinetics peak analysis of the TL gloW curve. A charge trap with a depth of 1.0 eV is responsible for the afterglow observed at room temperature. Ce3+ ions appear to be the luminescence centres in the recombination process of the trapped charge carriers. It will be shown that optical excitation in the 5d levels of Ce3+ produces trap filling. The possible nature of the charge traps will be discussed.