【Device Papers】Mg-doped β-Ga₂O₃ thin films for solar-blind ultraviolet photodetector

      Researchers from the University of Electronic Science and Technology of China  have published a dissertation titled "Mg-doped β-Ga₂O₃ thin films for solar-blind ultraviolet photodetector" in Applied Surface Science.

Abstract

      Beta gallium oxide (β-Ga₂O₃) is a promising material for solar-blind photodetectors owing to its suitable bandgap. However, the presence of oxygen vacancies often induces high dark current and trap states, limiting the device performance. In this work, magnesium-doped β-Ga₂O₃ [((MgGa)₂O₃)] thin films with different Mg concentrations were grown by molecular beam epitaxy (MBE). Metal–semiconductor–metal (MSM) photodetectors were then fabricated on these films. The device with a Mg concentration of 7.8 at% exhibited the best performance, achieving a photo-to-dark current ratio of 1.3 × 10⁷, a specific detectivity of 2.1 × 10¹⁵ Jones, and fast rise/decay times of 22.9 ms and 2.9 ms, respectively. Additionally, a superlinear photoresponse was observed, which was explained using a recombination-centers model. These results demonstrate that (MgGa)₂O₃ thin films are highly promising for high-performance solar-blind photodetectors.

DOI：

https://doi.org/10.1016/j.apsusc.2025.165700