Introduction

Abstract

When the section of the Dielectric Breakdown of the German Academy of Science in Berlin was created, we were to investigate the electrical behavior of single crystals, mainly cadmium sulfide at high-electric fields in the prebreakdown range. The only electrical tool we had at that time was the analysis of the current–voltage characteristics that started to show significant nonlinear deviations from the behavior at low fields. However, this characteristic is an insufficient tool to make important conclusions of the behavior of the field dependence of the carrier motion within the crystal. The measured current essentially integrates over all current channels within a crystal; and the field when dividing the applied voltage by the distance between the electrodes again is an averaged one that says little about the microscopic processes that create the nonlinearities of the current–voltage characteristics that we observed.