Electrical characteristics of an aluminum/amorphous selenium rectifying contact

Abstract

Rectifying contacts can be obtained between aluminum and amorphous selenium thin films. It is shown that the interfacial oxide layer makes a decisive contribution to the diode behavior. It is shown that, under forward bias, three regions are visible on the ln I vs V plots. A phenomenological model is proposed to explain these three different domains. It is suggested that under low bias the space charge width increases because of the trapping of carriers at the interface of Al/a-Se. At the saturation of this effect, a recombination process dominates. At high forward bias a series resistance effect becomes dominant. The reverse bias leakage region is due to tunneling of majority carriers via gap states.