GaN-based Schottky barrier ultraviolet photodetector with a 5-pair AlGaN-GaN intermediate layer

A GaN-based Schottky barrier diode (SBD) with a 5-pair AlGaN-GaN intermediate layer for ultraviolet (UV) photodetector (PD) was fabricated and investigated. It was found that we could achieve a smaller dark leakage current and noise level by using the 5-pair AlGaN-GaN intermediate layer. For our device biased at -5V, the responsivity at 360 nm was found to be 0.26 A/W and the UV-to-visible rejection ratio was estimated to be 1.83 x 10(4). At the same bias, it was found that minimum noise equivalent power and normalized detectivity of our device were 1.00 x 10(-9) W and 1.45 x 10(9) cm Hz 0.5 W-1, respectively. This indicates a simple and effective way to fabricate high-performance PDs for UV detection. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim