Pt/ZnGa2O4/p-Si Back-to-Back Heterojunction for Deep UV Sensitive Photovoltaic Photodetection with Ultralow Dark Current and High Spectral Selectivity

• DOI: 10.1021/acsami.1c23453
• Publication Date: 2022-01-24T16:58:42Z
• Authors: Dan Zhang; Zhuogeng Lin; Wei Zheng; Feng Huang
• Keywords: Photodetection; Ultraviolet

In this work, a strategy of constructing back-to-back heterojunction is proposed to fabricate Si-based photovoltaic photodetectors with high deep ultraviolet (DUV) spectral selectivity. By combining Pt thickness 4 nm ZnGa2O4/Si heterojunction, successfully constructed. Based on that, Pt/ZnGa2O4/p-Si DUV detector low dark current density (∼9.6 × 10-5 μA/cm2), large photo-to-dark ratio (PDCR, >105), and fast response speed (decay time <50 ms) fabricated. At 0 V bias, device displays photoresponsivity about 1.36 mA/W ultraviolet-visible (DUV-vis) rejection (R258 nm/R420 nm) ∼1.1 105, which are 1-2 orders magnitude higher than those most detectors reported currently. Even at working temperature 470 K, the detectivity can still reach ∼1.23 1010 Jones. addition, compared Au/ZnGa2O4/Si devices, PDCR Pt/ZnGa2O4/Si decrease by 2 increase 1 order magnitude, respectively. The enhanced performance be attributed Schottky barrier established between work function ZnGa2O4. This adopting structure hinder visible light photoresponse thus reduce provide reference for preparing excellent performance.