Voltage contrast imaging of barriers in ceramic semiconductors

Abstract

Potential barriers responsible for nonlinear conduction in ZnO ceramic semiconductors (cersems) have been observed by both the intensity and Y-modulation voltage contrast secondary electron microscopy techniques. The barriers exist at a grain-intergranular interface and extend into the conducting ZnO grains. The applied voltage is distributed uniformly across the barriers. No electrical shorting of the barriers has been observed at fields exceeding the breakdown.