Review of gallium-oxide-based solar-blind ultraviolet photodetectors

TLDR

Solar‑blind photodetectors are sought after for industrial, civil, environmental, and biological uses, and gallium oxide (Ga₂O₃), an emerging ultrawide‑bandgap semiconductor, offers unique advantages for high‑performance devices. This review surveys recent advances in Ga₂O₃ solar‑blind photodetectors across bulk crystals, epitaxial films, nanostructures, and ternary alloys, with a special emphasis on the mechanisms behind their large photoconductive gains. The authors summarize the basic working principles, fundamental properties, synthesis routes, and device processing of Ga₂O₃ photodetectors, and analyze the physical origins of the observed huge photoconductive gains. Advances in epitaxy and device processing have positioned Ga₂O₃‑based solar‑blind detectors as one of the most promising solutions for versatile UV detection applications.

Abstract

Solar-blind photodetectors are of great interest to a wide range of industrial, civil, environmental, and biological applications. As one of the emerging ultrawide-bandgap semiconductors, gallium oxide (Ga2O3) exhibits unique advantages over other wide-bandgap semiconductors, especially in developing high-performance solar-blind photodetectors. This paper comprehensively reviews the latest progresses of solar-blind photodetectors based on Ga2O3 materials in various forms of bulk single crystal, epitaxial films, nanostructures, and their ternary alloys. The basic working principles of photodetectors and the fundamental properties and synthesis of Ga2O3, as well as device processing developments, have been briefly summarized. A special focus is to address the physical mechanism for commonly observed huge photoconductive gains. Benefitting from the rapid development in material epitaxy and device processes, Ga2O3-based solar-blind detectors represent to date one of the most prospective solutions for UV detection technology towards versatile applications.