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

Abstract

Metastable ε-Ga2O3, 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-Ga2O3/ Sn-doped In2O3 (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 6.74×104, and a fast fall time of 40 ms while maintaining good performance across a broad illumination range of 90 to 4100 μW/cm2. Moreover, the device can operate in a self-powered mode at zero bias, further verifying the presence of a depletion region within the ε-Ga2O3/ITO heterojunction. Our results demonstrate that ε-Ga2O3 is promising for high-quality integration on ITO and application in DUV detection, offering new strategic directions for developing high-performance Ga2O3-based DUV PDs.