Photoeffects in potassium tantalate

摘要

Photoeffects in high‐resistivity samples of potassium tantalate having blocking metallic electrical contacts have been measured. We have observed photoconductive gains greater than unity and a rather broad spectral response. Examination of the photocurrent‐voltage characteristic and the results of a series of photomasking experiments reveals that the photocurrent is limited by the junction resistance at low bias, and that a transition to bulk‐ (surface) limited conduction occurs as the bias is increased. We have evidence that multiple photomechanisms exist in this material. In the bulk‐limited (high bias) regime, photodesorption of the surface is a contributing photomechanism.