High detectivity solar-blind high-temperature deep-ultraviolet photodetector based on multi-layered (l00) facet-oriented β-Ga₂O₃ nanobelts.

Fabrication of a high-temperature deep-ultraviolet photodetector working in the solar-blind spectrum range (190-280 nm) is a challenge due to the degradation in the dark current and photoresponse properties. Herein, β-Ga2O3 multi-layered nanobelts with (l00) facet-oriented were synthesized, and were demonstrated for the first time to possess excellent mechanical, electrical properties and stability at a high temperature inside a TEM studies. As-fabricated DUV solar-blind photodetectors using (l00) facet-oriented β-Ga2O3 multi-layered nanobelts demonstrated enhanced photodetective performances, that is, high sensitivity, high signal-to-noise ratio, high spectral selectivity, high speed, and high stability, importantly, at a temperature as high as 433 K, which are comparable to other reported semiconducting nanomaterial photodetectors. In particular, the characteristics of the photoresponsivity of the β-Ga2O3 nanobelt devices include a high photoexcited current (>21 nA), an ultralow dark current (below the detection limit of 10(-14) A), a fast time response (<0.3 s), a high R(λ) (≈851 A/W), and a high EQE (~4.2 × 10(3)). The present fabricated facet-oriented β-Ga2O3 multi-layered nanobelt based devices will find practical applications in photodetectors or optical switches for high-temperature environment.