Progress in ε / κ -Ga 2 O 3 growth and devices

Abstract ε/κ -Ga 2 O 3 has attracted increasing attention due to its ultra-wide bandgap, unique piezoelectric properties, and high lattice symmetry, demonstrating significant potential in applications such as solar-blind ultraviolet detectors and high-voltage or high-power devices. This review systematically summarizes recent advances in growth methods for high-quality ε/κ -Ga 2 O 3 films, ε/κ -Ga 2 O 3 -based alloys, and n-type ε/κ -Ga 2 O 3 thin films. Based on high-quality ε/κ -Ga 2 O 3 thin films, state-of-the-art ε/κ -Ga 2 O 3 devices have been fabricated, including solar-blind photodetectors, Schottky barrier diodes, heterojunction diodes, and metal–oxide-semiconductor field-effect transistors. Finally, we present perspectives on both the promising prospects and critical challenges facing ε/κ -Ga 2 O 3 research.