Electrical conduction in single crystal trigonal selenium

Abstract

Experiments are described which provide conclusive evidence for space charge conduction in homogeneous single crystals of trigonal selenium. From measurements of thermal activation energies for both ohmic and space charge limited currents over a broad temperature range localized levels have been calculated to lie at approximately 0.09, 0.21 and 0.47 eV from the valence band. Supporting data on thermally stimulated currents and ac conductivity have further established that conduction processes in this elemental semiconductor must be understood in terms of the normal energy band picture.