Al0.25Ga0.75N / GaN Schottky Barrier Photodetectors with an Al0.3Ga0.7N Intermediate Layer

Abstract

AlGaN/GaN Schottky barrier photodetectors (PDs) with and without a low temperature (LT) AlGaN intermediate layer (IML) were both fabricated and characterized. It was found that we can reduce dark leakage current by around 4 orders of magnitude and enhance UV-to-visible rejection ratio by around 2 orders of magnitude by using an LT AlGaN IML. With −5 V applied bias, we can achieve lower noise equivalent power and higher normalized detectivity of the PD, which were and , respectively, with an LT AlGaN IML.