Review of deep ultraviolet photodetector based on gallium oxide

Qin Yuan^{1, 3}, Long Shibing^{2, 3, †}, Dong Hang^{1, 3}, He Qiming¹, Jian Guangzhong^{1, 3}, Zhang Ying^{1, 3}, Hou Xiaohu², Tan Pengju², Zhang Zhongfang², Lv Hangbing^{1, 3}, Liu Qi^{1, 3}, Liu Ming^{1, 3}

(a) The I–V characteristics of the β-Ga₂O₃ thin films MSM photodetector without and with annealing treatment in O₂ atmosphere in the dark. The inset (bottom right) shows the schematic figure of the MSM structure. The inset (top left) is the plot of (α hν)² as a function of hν calculating from UV–vis absorbance spectrum of the β-Ga₂O₃ thin film. (b) Normalized O 1s XPS spectra of the as-grown and post-annealed β-Ga₂O₃ thin films. (c) Time-dependent photoresponse of the β-Ga₂O₃ thin films MSM photodetector under 254 nm illumination. (d) Enlarged view of the rise/decay edges of the transient photoresponse curve and its corresponding exponential fitting.^[18]