Facile method for reducing decay time in GaN-based ultraviolet photodetector using microheater

Abstract

Gallium nitride (GaN), a wide-bandgap III-V compound semiconductor, is currently regarded as a promising material for ultraviolet (UV) photodetectors. However, persistent photoconductivity (PPC) attributed to deep-level defects has been widely reported. This undesirable phenomenon is one of the most challenging issues and needs to be solved to commercialize the material as a reliable device in the future. In this study, a facile method is suggested to suppress the PPC for the rapid recovery of the dark-current level in GaN-based UV photodetectors by employing an additional microheater on the device. Through Joule heating, thermal energy is supplied to the GaN film to accelerate the carrier capture rate. For the transient current measurements, the decay time of the microfabricated device was calculated and compared after exposure to 365-nm UV illumination at various heater powers (thermal heating sources) simultaneously. As a result, a 99% decrease in decay time was measured (similar to 11501s for 0 W and similar to 84 s for 2.002 W). Based on these results, a facile method was developed in this study to suppress PPC in a reliable device by simple device heating. (C) 2020 Elsevier B.V. All rights reserved.