This letter demonstrates a high performance β-Ga ₂ O ₃ solar-blind metal-oxide-semiconductor field-effect phototransistor (SBPT) with Hafnium Oxide (HfO ₂ ) Gate Dielectric. The SBPT shows a high Photo-to-dark-current ratio (PDCR) of 6.9×10 ⁷ , an I _{254 nm} / I _{365 nm} rejection ratio of 6.0×10 ⁷ combined with an external quantum efficiency (EQE) of 6.4×10 ⁷ %. In addition, benefit from stronger control capability of the HfO ₂ based gate structure, the fabricated SBPT reaches a record detectivity ( D *) of 1.1×10 ¹⁹ Jones and ultrahigh responsivity ( R) of 1.4×10 ⁷ A/W. Furthermore, short decay time ( τ _d ) is obtained to be as low as 16 ms. These outstanding properties indicate that SBPT is promising for the solar-blind detection.

In this letter, we demonstrate a high performance lateral β-Ga2O3 solar-blind Schottky barrier photodiode (SBPD) with record detectivity (D*) and ultrahigh gain via carrier multiplication process. Due to the strong electric field, the carriers generated under the 254 nm light illumination undergo acceleration and impact ionization, contributing to the internal carrier multiplication process. Therefore, the photodetector (PD) is equipped with record D* of 2×1016 Jones and ultrahigh gain of 1.7 × 104, combining with a high photo-to-dark-current ratio of more than 105, a responsivity of 1.2×105 A/W and a large external quantum efficiency of 5.6×105 %. Without the requirement of complex device structure like other avalanche PDs, our SBPD can be used as a low-cost and easy-to-integrate technology to prepare high performance solar-blind PDs.

Due to the excellent responsivity and high rejection ratio, Ga₂O₃-based solar-blind ultraviolet photodetectors (PDs) are attracting more and more attention. The excellent material quality ensures great performance of PDs. In this review, we summarize recent advancements in growth methods of β-Ga₂O₃ bulk and thin films. Based on high-quality substrates and thin films, numerous state-of-art Ga₂O₃-based PDs have been reported in decades. Therefore, we collect some representative achievements in Ga₂O₃-based PDs, summarizing the development process of each type of structure. Furthermore, the advantages and disadvantages of different structures are also discussed to provide practical reference for researchers in this field. Additionally, inspired by the excellent performance of Ga₂O₃-based PDs, many research teams have also explored the applications based on solar-blind detection. We summarize three application fields, including imaging, light communication, and optical tracing, introducing some excellent works from different teams. Finally, we evaluate the outlook and remaining challenges in the future development of Ga₂O₃-based PDs.