Influence of annealing pretreatment in different atmospheres on crystallization quality and UV photosensitivity of gallium oxide films

Abstract

Due to their high wavelength selectivity and strong anti-interference capability, solar-blind UV photodetectors hold broad and important application prospects in fields like flame detection, missile warnings, and secure communication. Research on solar-blind UV detectors for amorphous Ga₂O₃ is still in its early stages. The presence of intrinsic defects related to oxygen vacancies significantly affects the photodetection performance of amorphous Ga₂O₃ materials. This paper focuses on growing high quality amorphous Ga₂O₃ films on silicon substrates through atomic layer deposition. The study investigates the impact of annealing atmospheres on Ga₂O₃ films and designs a blind UV detector for Ga₂O₃. Characterization techniques including atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) are used for Ga₂O₃ film analysis. Ga₂O₃ films exhibit a clear transition from amorphous to polycrystalline after annealing, accompanied by a decrease in oxygen vacancy concentration from 21.26% to 6.54%. As a result, the response time of the annealed detector reduces from 9.32 s to 0.47 s at an external bias of 10 V. This work demonstrates that an appropriate annealing process can yield high-quality Ga₂O₃ films, and holds potential for advancing high-performance solar blind photodetector (SBPD) development.