6533b7defe1ef96bd127659a

RESEARCH PRODUCT

Formation of luminescence centres under excitation with electron beams in PbWO 4 and ZnWO 4 crystals

subject

description

The leading edge of intrinsic luminescence pulse in PbWO 4 and ZnWO 4 single crystals is studied. The rise of luminescence intensity is observed after excitation with electron beam pulse. The luminescence rise is shown tobe a result of luminescence center formation via electron-hole recombination within spatially correlated pairs. An electron of a geminate electron-hole pair of PbWO 4 crystal self-traps and stimulates self-trapping of a hole at a close distance. In the ZnWO 4 crystal a hole of a geminate electron-hole pair self-traps and stimulates self-trapping of the electron producing a W 5 + center at a short distance. The rise-time of luminescence depends on spatial separation of recombining components. It is short even at 80 K (100 ns in PbWO 4 and 10 ns in ZnWO 4 ). The reasons for different rise time and different spatial distribution of electron and hole self-trapped centers are discussed.