AlGaN/GaN/AlGaN ultraviolet photodetectors on Si

AlGaN/GaN/AlGaN ultraviolet photodetectors were grown on Si [111] substrates using an AlN buffer by metalorganic chemical vapor deposition. These detectors showed a high response in a narrow range of wavelength with a peak position at 365 nm. A peak responsivity of 24 A/W was obtained at 5.5 V bias. This high responsivity is mainly due to the high polarization electric-field in GaN layer of AlGaN/GaN/AlGaN heterojunction structure and the potential wells at AlGaN/GaN interfaces.