【Domestic Papers】High-performance Type-Ⅰ Sn-doped-Ga₂O₃/SnSe₂ Heterojunction Photodetectors Enabled by Fowler-Nordheim Tunneling

      Researchers from the South China Normal University have published a dissertation titled "High-performance Type-Ⅰ Sn-doped-Ga₂O₃/SnSe₂ Heterojunction Photodetectors Enabled by Fowler-Nordheim Tunneling" in Applied Physics Letters.

Project Support

      This work was supported by the National Natural Science Foundation of China (No. 62474165, 11974122 and U22A2073), Science and Technology Major Project of Henan Province (231100230300), the Foundation of National Key Laboratory of Plasma Physics (Grant No. 6142A04240204), Henan Association for Science and Technology Youth Talent Support Program (2024HYTP024) and the Scientific Research Innovation Project of Graduate School of South China Normal University.

Abstract

      Gallium oxide (Ga₂O₃) is renowned for its exceptional physical and chemical properties, making it an ideal material for solar-blind photodetectors. In this study, Sn-doped-Ga₂O₃ microwires (MWs) were utilized to fabricate a type-I heterojunction photodetector with SnSe₂. The Sn-doped-Ga₂O₃ MW/SnSe₂ hybrid van der Waals heterojunction exhibits both direct tunneling and Fowler–Nordheim tunneling under positive voltages. By exploiting the Fowler–Nordheim tunneling mechanism at a 6 V bias, the device demonstrates outstanding performance under 254 nm illumination, achieving a rectification ratio of 10⁴–10⁵, an ultralow dark current of 0.11 pA, a responsivity of 81.82 A/W, a detectivity of 7.79 × 10¹⁴ Jones, and an exceptionally high external quantum efficiency of 4 × 10⁴%. These impressive characteristics make the heterojunction photodetector highly suitable for high-quality imaging applications. This research offers a promising processing solution for Ga₂O₃-based optoelectronic devices, further extending their potential for versatile solar-blind detection and imaging applications.