Thermally stimulated conductivity in semi-insulating gallium arsenide at low and intermediate electric fields

Abstract

A method of producing and investigating trapping effects in semiconductors and insulators has been devised which uses the variation of applied electric field strength during the measurement of thermally stimulated conductivity. Experiments on chromium-, oxygen-, and iron-doped semi-insulating gallium arsenide crystals have shown that a change in the electric field may shift existing peaks, excite new peaks, or induce the enhancement, broadening, narrowing or quenching of the existing peaks in the thermally stimulated conductivity spectrum. At relatively high fields, current instabilities were sometimes observed in the region of a peak. It is suggested that these changes are caused mainly by the modification of the capture cross section of the traps.