Effect of NH3 plasma treatment on the transient characteristics of ZnO nanorod-gated AlGaN/GaN high electron mobility transistor-based UV sensors

Abstract

In this work, we examine the effect of NH3 plasma post-treatment on the ultraviolet (UV) photo-response transient characteristics of zinc oxide (ZnO) nanorod (NR)-gated AlGaN/GaN high electron mobility transistor (HEMT) photodetectors. The recovery time of the detectors (180ms) was significantly reduced to 80ms by the NH3 plasma-treatment for 180s, while no significant reduction in response time upon UV illumination is measured from the plasma-treated devices. The photoluminescence and X-ray diffraction reveals that continuous improvement in crystalline quality of NRs is observed with the plasma duration up to 180s. The X-ray photoelectron spectroscopy measurement shows that the surface band bending of ZnO crystals is lowered with the corresponding plasma treatment.