Self-Powered Solar-Blind UV Photodetector Based on Core–Shell Heterojunction with Lu₂O₃ Nanolayer Modified β-Ga₂O₃ Microwire

Solar-blind ultraviolet (UV) photodetectors play a critical role in ultraviolet communication and monitoring, effectively reducing false alarm rates and improving the accuracy of detection systems across various settings, which has garnered significant attention. Due to its exceptional solar-blind photon absorption coefficient, extremely stable structure, and ultrawide bandgap (4.5–4.9 eV), Ga 2 O 3 has recently been identified as a desirable material for solar-blind UV photodetectors. Heterojunctions can separate photogenerated electron–hole pairs and their absorption edges can be controlled by selecting semiconductors with appropriate bandgaps, making them an important technology for light detection. In this work, a self-powered solar-blind UV photodetector has been fabricated using a mechanically separated β-Ga 2 O 3 /Lu 2 O 3 core–shell microwire heterostructure. Our device demonstrates excellent solar-blind UV discriminability with self-powered photodetection, the device exhibits a responsivity of 38.8 mA/W, a detectivity of 1.22 × 10 12 Jones, a switching ratio of 1.43 × 10 3, and a decay rate under UV irradiation of 62 ms, benefiting from both photovoltaic and photoconductive effects. Due to the high dielectric constant of Lu 2 O 3 thin films at the nanoscale, enables more effective modulation of internal electric fields within heterojunction structures, thereby enhancing the response speed and sensitivity of photodetectors. The application of self-powered photodetectors in solar-blind communication systems has achieved promising results, which provides a viable strategy for Ga 2 O 3 -based high-performance self-powered photodetectors.