Gallium oxide (Ga₂O₃) is a representative of ultra-wide bandgap semiconductors, with a band gap of about 4.9 eV. In addition to a large dielectric constant and excellent physical and chemical stability, Ga₂O₃ has a theoretical breakdown electric field strength of more than 8 MV cm⁻¹, which is 27 times more than that of Si and about twice as large as that of SiC and GaN. It is guaranteed that Ga₂O₃ has irreplaceable applications in ultra-high-power (1–10 kW) electronic devices. Unfortunately, due to the difficulty of p-type doping of Ga₂O₃, the full Ga₂O₃-based bipolar devices face more difficulties, and the unipolar Ga₂O₃ power Schottky diodes are feasible, but substantial progress has been made in recent years. In this article, we review the advanced progress and important achievements of the state-of-the-art Ga₂O₃-based power Schottky barrier diodes, and provide staged guidance for the further development of Ga₂O₃ power devices. Multiple types of device architectures, including basic structure, edge terminal processing, field-plated, trench and heterojunction p–n structure, will be discussed in detail.

Nitrogen-doping in Ga₂O₃ films is proposed to decrease the concentration of oxygen vacancies and further improve the performance of solar-blind ultraviolet photodetectors.

β -Gallium oxide ( β -Ga ₂ O ₃ ) has been studied extensively in recent decades due to its excellent usability in fabricating a variety of devices, such as solar-blind photodetectors and power devices. However, as an important part of a device, related investigations of β -Ga ₂ O ₃ –metal contacts, especially for Schottky contacts, are rare. In this review, we summarize recent research progress on β -Ga ₂ O ₃ –metal contacts, including related theories, measurements, fabrication processes, control methods, etc. This review will provide insights for both theoretical understanding of the metal/semiconductor interface, as well as the fabrication process for engineering applications of Ga ₂ O ₃ -based devices.

Oxygen vacancy (VO) defects are ubiquitous in oxide semiconductors and usually served as charge carriers recombination centers to depress the device performance. Herein, a surface VO defect compensation engineering is conducted to modulate the VO and improve the device performance of $\beta $ -Ga $_{\text{2}}$ O $_{\text{3}}$ film via oxygen-plasma treatment. As a result, the photodetectors (PD) based on 30 min oxygen-plasma treated Gallium oxide (Ga $_{\text{2}}$ O $_{\text{3}}\text{)}$ film not only exhibit record-low dark current of 5 fA, over three orders of magnitude times higher responsivity rejection ratio ( $\textit{R}_{\text{250}}$ / $\textit{R}_{\text{400}}\text{)}$ , and faster rise and decay speed than the untreated device but also the oxygen-plasma-treated PDs exhibits exceptional sensitivity to detect extremely weak UV signals (0.1 $\mu $ W/cm $^{\text{2}}\text{)}$ with a photo-to-dark current ratio of $\sim$ 10 $^{\text{4}}$ . Also, it is discovered that the device based on oxygen plasma has excellent photoelectric stabilities. The defect engineering with surface plasma treatment offers an efficient strategy for the high performance of Ga $_{\text{2}}$ O $_{\text{3}}$ film devices.

The device has a dark current of 12.09 pA and achieves an outstanding responsivity of 44.09 A W⁻¹, a high detectivity of 5.84 × 10¹² Jones.