Self-Powered Solar-Blind\nUV Photodetector Based on\nCore–Shell Heterojunction with Lu<sub>2</sub>O<sub>3</sub> Nanolayer\nModified β‑Ga<sub>2</sub>O<sub>3</sub> Microwire

Solar-blind ultraviolet (UV) photodetectors play a critical\nrole\nin ultraviolet communication and monitoring, effectively reducing\nfalse alarm rates and improving the accuracy of detection systems\nacross various settings, which has garnered significant attention.\nDue to its exceptional solar-blind photon absorption coefficient,\nextremely stable structure, and ultrawide bandgap (4.5–4.9\neV), Ga<sub>2</sub>O<sub>3</sub> has recently been identified as a\ndesirable material for solar-blind UV photodetectors. Heterojunctions\ncan separate photogenerated electron–hole pairs and their absorption\nedges can be controlled by selecting semiconductors with appropriate\nbandgaps, making them an important technology for light detection.\nIn this work, a self-powered solar-blind UV photodetector has been\nfabricated using a mechanically separated β-Ga<sub>2</sub>O<sub>3</sub>/Lu<sub>2</sub>O<sub>3</sub> core–shell microwire heterostructure.\nOur device demonstrates excellent solar-blind UV discriminability\nwith self-powered photodetection, the device exhibits a responsivity\nof 38.8 mA/W, a detectivity of 1.22 × 10<sup>12</sup> Jones,\na switching ratio of 1.43 × 10<sup>3</sup>, and a decay rate\nunder UV irradiation of 62 ms, benefiting from both photovoltaic and\nphotoconductive effects. Due to the high dielectric constant of Lu<sub>2</sub>O<sub>3</sub> thin films at the nanoscale, enables more effective\nmodulation of internal electric fields within heterojunction structures,\nthereby enhancing the response speed and sensitivity of photodetectors.\nThe application of self-powered photodetectors in solar-blind communication\nsystems has achieved promising results, which provides a viable strategy\nfor Ga<sub>2</sub>O<sub>3</sub>-based high-performance self-powered\nphotodetectors.