Temperature Dependence of Drift Mobility in Bismuth Germanium Oxide and Bismuth Silicon Oxide

摘要

We have measured the temperature dependence of the electron mobility between approx 200 K and 300 K in undoped and 0.3percent Fe-doped Bi_(12)GeO_(20) (BGO) and undoped Bi_(12)SiO_(20) (BSO) using a time-of-flight (TOF) technique. We were able to measure electron current transients over a wide temperature range. We found that mobilities calculated from the observed transit times were independent of sample thickness and applied voltage, but depended approximately exponentially on temperature. The hole current transients were very weak and featureless, so we were unable to measure mobilities for holes.