【Device Papers】ngineering Interfacial Defects in β-Ga₂O₃/Lu₂O₃ Heterojunctions for Achieving High Detectivity in Self-Powered Solar-Blind UV Communication

      Researchers from the Zhejiang Sci-Tech University have published a dissertation titled "Engineering Interfacial Defects in β-Ga₂O₃/Lu₂O₃ Heterojunctions for Achieving High Detectivity in Self-Powered Solar-Blind UV Communication" in ACS Applied Electronic Materials.

Abstract

      Solar-blind ultraviolet (SBUV) optical communication system leverages atmospheric ozone absorption to fulfill low background noise, enabling high anti-interference and security in complex environments, which has gradually attracted widespread attention. Gallium oxide (Ga₂O₃) as an ultrawide bandgap semiconductor possesses excellent physicochemical stability and electron mobility, making it an ideal choice for photodetectors in SBUV communication systems due to its intrinsic spectral alignment with the solar-blind spectrum. Nevertheless, high-concentration oxygen vacancy defects and deep intrinsic acceptor levels, respectively, constrain conventional Ga₂O₃-based photodetectors’ responsivity and block homojunction formation via p-doping. Furthermore, externally biased metal–semiconductor-metal structure devices pose challenges in attaining miniaturization and integration simplicity. To address these constraints, this study employed plasma-enhanced chemical vapor deposition combined with spin-coating processes to fabricate an annealing-optimized β-Ga₂O₃/Lu₂O₃ heterojunction photodetector with a precisely modulated oxygen vacancy concentration. The 650 °C-annealed detector realized a low dark current, a 5.1 × 10³ photo-to-dark current ratio, and a 7.07 × 10¹¹ Jones detectivity under 254 nm illumination at 0 V. First-principles calculations corroborated that carrier transport across the heterojunction interface is governed by a type-II band alignment. Significantly, a high-fidelity solar-blind ultraviolet communication system using a β-Ga₂O₃/Lu₂O₃ heterojunction detector achieved accurate baseband transmission via on–off keying modulation. The present work supplies a key foundation for the design and fabrication of subsequent-generation self-powered SBUV optical communication systems.

DOI：

https://doi.org/10.1021/acsaelm.5c02065