The growth and expansive applications of amorphous Ga<sub>2</sub>O<sub>3</sub>
Zhaoying Xi, Lili Yang, Lincong Shu, Maolin Zhang, Shan Li, Li Shi, Zeng Liu, Yufeng Guo, Weihua Tang
Abstract
As a promising ultra-wide bandgap semiconductor material, gallium oxide (Ga 2 O 3 ) is attracting extensive attention of researchers due to its feasible growth process, appropriate bandgap of 4.4 eV–5.3 eV allowing for deep-ultraviolet (deep-UV) detection, good physical and chemical stability, high breakdown field strength and electron mobility, etc. Different from the strict processes for controllable crystalline Ga 2 O 3 (usually refer to as stable monoclinic β -Ga 2 O 3 ), amorphous Ga 2 O 3 (a-Ga 2 O 3 ) film can be prepared uniformly at low temperature on a large-area deposition substrate, suggesting great advantages such as low manufacturing cost and excellent flexibility, dispensing with high-temperature and high vacuum techniques. Thus, a-Ga 2 O 3 extremely facilitates important applications in various applied fields. Therefore, in this concise review, we summarize several major deposition methods for a-Ga 2 O 3 films, of which the characteristics are discussed. Additionally, potential methods to optimize the film properties are proposed by right of the inspiration from some recent studies. Subsequently, the applications of a-Ga 2 O 3 thin films, e.g., in photodetectors, resistive random access memories (RRAMs) and gas sensors, are represented with a fruitful discussion of their structures and operating mechanisms.