Thermally stimulated current studies of bismuth germanium oxide crystal

Abstract

Thermally stimulated current (TSC) from nominally undoped Bi 12GeO20 (BGO) crystals was measured as a function of the uv excitation temperature and time. The results were compared with the previous work on Bi12SiO 20 (BSO). The correlation in trapping kinetics among the three major traps observed previously in BSO appears to hold also for BGO; i.e., the shallowest trap acts as a precursor state for electrons to be trapped into the deeper traps. However, an additional finding on the temperature dependence of trap density in the TSC curves of BGO indicates that the simple model proposed earlier is not strictly valid and further study is required.