p-GaN/n-IGZO self-powered ultraviolet photodetector with ultralow dark current and high sensitivity

Self-powered ultraviolet (UV) photodetector has attracted growing research interest for applications in biological and human related fields with a low power consumption. However, typical construction strategies of hetero-junction require materials with high crystal quality to realize high device performance with low dark current, which normally necessitates costly thin film epitaxy process. In our study, a high sensitivity self-powered UV photodetector with an ultralow dark current has been proposed by constructing p-GaN/n-IGZO heterojunction via a facile room temperature sputtering of IGZO thin film on commercially available p-GaN/sapphire substrate. By implementing UV-Ozone surface treatment to introduce an ultrathin oxide layer in the junction interface, dark current of the photodetector can be as low as 0.45 pA, which leads to a high detectivity of 1.9 x 1013 Jones with a rise time of 0.92 ms and a decay time of 11.61 ms when operating in self-powered mode. Our work has put forward a facile and cost-effective route for developing highly sensitive UV detecting devices with a low dark current and a low power consumption, which paves the path to advances in green industry of UV optoelectronics.

Automated summary

In this research, a high sensitivity self-powered UV photodetector with low dark current and low power consumption was developed by constructing a heterojunction on a commercially available substrate. The detector exhibited excellent performance with a dark current as low as 0.45 pA, a detectivity of 1.9 x 1013 Jones, and fast response times. This work provides a cost-effective approach for the development of highly sensitive UV detecting devices.