Reduction of dark current in AlGaN/GaN Schottky barrier photodetectors with a low-temperature-grown GaN cap layer

摘要

AlGaN/GaN-based ultraviolet (UV) Schottky barrier photodetectors (PDs) with and without the LT GaN cap layer were both fabricated. It was found that we could achieve a lower leakage current from sample A. With incident light wavelength of 320 nm and a -1 V reverse bias, the measured responsiviyy was around 0.03 A/W and 0.015 AAV for samples with and without the LT GaN cap layer, respectively. The response speed of the sample A was also found to be faster.