A self-powered ultraviolet photodiode using an amorphous InGaZnO/p-silicon nanowire heterojunction

Abstract

This study proposes a novel photodetector (PD) that uses an amorphous InGaZnO (IGZO)/silicon nanowires (SiNWs) heterojunction, in which the IGZO functions as an ultraviolet (UV) light absorption layer and the nanowires provide carrier conduction paths and light trapping centers. The p-n heterojunction shows excellent rectification characteristics in the dark and distinctive photovoltaic behavior under UV illumination. A high responsivity of 0.53 A/W at 380 nm and a quick response time of less than 0.2 ms are achieved. The device exhibits self-powering characteristics under UV illumination due to the amorphous phase of IGZO. The architecture, which combines a wide-bandgap a-IGZO (~3.5 eV) with a narrow-bandgap SiNWs, means that the photo-detection spectra extend from UV to near-infrared. This study demonstrates that the a-IGZO/SiNWs PD is suitable for applications that require high response speeds, broadband detection and self-sufficient functionality.