【Device Papers】Self-powered UV photodetector based on type-II Be₀.₀₆Zn₀.₉₄O₀.₇₇S₀.₂₃/Ga₂O₃ heterojunction with dual built-in electric fields synergy

      Researchers from the Hubei Minzu University have published a dissertation titled "Self-powered UV photodetector based on type-II Be₀.₀₆Zn₀.₉₄O₀.₇₇S₀.₂₃/Ga₂O₃ heterojunction with dual built-in electric fields synergy" in European Physical Journal Special Topics.

Abstract

      Wide-bandgap oxide semiconductors, particularly ZnO and Ga₂O₃, have emerged as promising candidates for short-wavelength optoelectronic devices due to their outstanding optoelectronic properties and excellent chemical/thermal stability. This study innovatively combines a ZnO-based quaternary alloy (BeZnOS) with Ga₂O₃, proposing a novel high-performance Be_0.06Zn_0.94O_0.77S_0.23/Ga₂O₃ heterojunction self-powered ultraviolet photodetector. The heterojunction thin films were grown by pulsed laser deposition and exhibit clearly defined structural properties: Be_0.06Zn_0.94O_0.77S_0.23 alloy forms a phase-pure hexagonal wurtzite structure with a bandgap of 3.54 eV, while Ga₂O₃ maintains the monoclinic structure with a bandgap of 4.92 eV. The strategic co-substitution of isovalent Be²⁺ and S²⁻ in ZnO enables synergistic band structure engineering, resulting in a type-II band alignment at the heterointerface. The fabricated heterojunction photodetectors exhibit stable self-powered operation with high sensitivity and rapid response characteristics. Compared to the Al/BeZnOS/Ga₂O₃/Al structure, the Pt/BeZnOS/Ga₂O₃/Al architecture demonstrates enhanced self-powered ultraviolet detection performance. The enhanced self-powered operation is attributed to the synergistic built-in electric fields from both the BeZnOS/Ga₂O₃ heterojunction and the Pt/BeZnOS Schottky contact, which jointly promote efficient carrier separation and transport. Our work provides valuable insights into band engineering of ZnO-based materials and establishes a promising platform for developing high-performance all-oxide deep-ultraviolet photodetectors.

DOI：

https://doi.org/10.1140/epjs/s11734-026-02264-4