Ultraviolet photoresponse of ZnO nanostructured AlGaN/GaN HEMTs

Abstract

We present the first active visible blind ultraviolet (UV) photodetector based on zinc oxide (ZnO) nanostructured AIGaN/GaN high electron mobility transistors (HEMTs). The ZnO nanorods (NRs) are selectively grown on the gate area by using hydrothermal method. It is shown that ZnO nanorod (NR)-gated UV detectors exhibit much superior performance in terms of response speed and recovery time to those of seed-layer-gated detectors. It is also found that the best response speed (similar to 10 and similar to 190 ms) and responsivity (similar to 1.1 x 10(5) A/W) were observed from detectors of the shortest gate length of 2 mu m among our NR-gated devices of three different gate dimensions, and this responsivity is about one order higher than the best performance of ZnO NR-based UV detectors reported to date. (C) 2016 Elsevier Ltd. All rights reserved.