GaN Metal-Semiconductor-Metal Ultraviolet Photodetectors with Ir∕Pt Contact Electrodes

Nitride-based ultraviolet metal-semiconductor- metal photodetectors with Ir/ Pt and Ni/ Au Schottky electrodes were fabricated. It was found that room-temperature effective Schottky barrier height was 0.79 eV for Ir/ Pt on GaN. It was also found that we could achieve a 60 times smaller dark current and a 20 times larger photocurrent to dark current contrast ratio by using Ir/ Pt contact electrodes. With a 5 V applied bias and an incident light wavelength of 350 nm, it was found that measured responsivity was 0.132 A/ W for the detector with Ir/ Pt contact electrodes. (c) 2006 The Electrochemical Society.