HOT HOLES IN IRRADIATED IONIC SOLIDS

The concept of hot holes as energy carriers in irradiated ionic solids, mainly in alkali halides, is reviewed. This concept has been rised to understand the transfer of a considerable portion of radiation-created heres to impurity centers on irradiation of alkali halides at low temperatures where self-trapped holes are practically immobile. It has further been used to handle the nm-to-mu m range bulk-to-surface energy transport in alkali halides and metal oxides irradiated by XUV (synchrotron) radiation. This transport may be considered as bore diffusion with the mean free path of about 10 nm, the diffusion length of about 100 nm and the diffusion time of about 1 ps, which is consistent with the model in which hot holes behave as band particles, their motion being limited by hole-phonon scattering. The holes having reached the crystal surface recombine with conduction electrons which leads to surface recombination luminescence and possibly to creation of surface defects.