Photoconductive processes in Al2O3 films

摘要

Photocurrents have been measured in pyrolytic Al2O3 films on silion using strongly absorbed vacuum uv radiation. These currents show a behavior similar to that observed in SiO2 films; namely, there is a primary photocurrent component and a secondary component which results after the trapping of holes in the oxide enhances tunnel injection of electrons from the silicon electrode. The electron injection is observed with smaller applied fields in Al2O3 because of the trap‐assisted tunneling mechanism known to be active in this material. Interpretation of the results is complicated by the presence of both electron and hole traps. Nevertheless, two limiting models are proposed to provide a qualitative explanation.