Gain mechanism in GaN Schottky ultraviolet detectors

Schottky barrier GaN ultraviolet detectors, both in vertical and in lateral configuration, as well as in a metal-semiconductor-metal geometry were implemented. All devices exhibit a high gain at both reverse and forward bias. The photoresponse in the forward bias is in the positive current direction. We attribute the gain to trapping of minority carriers at the semiconductor-metal interface. The excellent agreement between the calculated responsivity and the experiment indicates that the model is valid for all device structures under study, and represents a unified description of gain mechanism in GaN Schottky detectors. (C) 2001 American Institute of Physics.