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

• Published in: RSC advances 2024-01, Vol.14 (7), p.4543-4555
• Main Authors: Chen, Wen-Jie, Ma, Hong-Ping, Gu, Lin, Shen, Yi, Yang, Ruo-Yun, Cao, Xi-Yuan, Yang, Mingyang, Zhang, Qing-Chun
• Format: Article
• Language: English
• Subjects: Amorphous materials; Annealing; Atmospheres; Atomic layer epitaxy; Crystal defects; Crystallization; Gallium oxides; Oxide coatings; Oxygen; Photoelectrons; Photometers; Photosensitivity; Silicon substrates; Ultraviolet detectors; X ray photoelectron spectroscopy
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d3ra07568k

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 Ga 2 O 3 is still in its early stages. The presence of intrinsic defects related to oxygen vacancies significantly affects the photodetection performance of amorphous Ga 2 O 3 materials. This paper focuses on growing high quality amorphous Ga 2 O 3 films on silicon substrates through atomic layer deposition. The study investigates the impact of annealing atmospheres on Ga 2 O 3 films and designs a blind UV detector for Ga 2 O 3 . Characterization techniques including atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) are used for Ga 2 O 3 film analysis. Ga 2 O 3 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 Ga 2 O 3 films, and holds potential for advancing high-performance solar blind photodetector (SBPD) development. 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.