High-performance deep-ultraviolet photodetector based on a single-crystalline ϵ-Ga₂O₃/Sn-doped In₂O₃ heterojunction

Abstract Metastable ϵ -Ga 2 O 3 , with its superior physical properties and high substrate compatibility, demonstrates considerable potential in developing heterojunction deep-ultraviolet photodetectors (DUV PDs). Herein, we fabricate a high-performance DUV PD utilizing a single crystalline ϵ -Ga 2 O 3 / Sn-doped In 2 O 3 (ITO) heterojunction. Under a reverse bias of 15 V, the device exhibits a high responsivity of 506 A/W, an excellent UV/visible rejection ratio of 6.74 × 10 4 , and a fast fall time of 40 ms while maintaining good performance across a broad illumination range of 90–4100 μ W cm −2 . Moreover, the device can operate in a self-powered mode at zero bias, further verifying the presence of a depletion region within the ϵ -Ga 2 O 3 /ITO heterojunction. Our results demonstrate that ϵ -Ga 2 O 3 is promising for high-quality integration on ITO and application in DUV detection, offering new strategic directions for developing high-performance Ga 2 O 3 -based DUV PDs.