Amorphous Ga<sub>2</sub>O<sub>3</sub> Thin-Film Phototransistors for Imaging and Logic Illustration
Xingqi Ji, Yuzhuo Yuan, Xuemei Yin, Shiqi Yan, Zijian Ding, Jiawei Zhang, Qian Xin, Aimin Song
Abstract
Amorphous Ga2O3 (a-Ga2O3) thin-film phototransistors were fabricated by sputtering and achieved excellent solar-blind detection properties with superhigh responsivity of 2.0 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{5}}\,\,\text{A}\cdot \text{W}^{-{1}}$ </tex-math></inline-formula> , ultrahigh detectivity of 4.9 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{18}}$ </tex-math></inline-formula> Jones, high external quantum efficiency of 9.9 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{7}}$ </tex-math></inline-formula> %, and high photo-to-dark current ratio of 2.9 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times \,\,10^{{8}}$ </tex-math></inline-formula> . These values are considerably high compared with those of the reported a-Ga2O3 phototransistors, and are comparable to or even better than those of the reported high-performance crystalline <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula> -Ga2O3 phototransistors. A 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times10$ </tex-math></inline-formula> a-Ga2O3 thin-film phototransistor array was fabricated, showing a clear “SDU” pattern with high contrast. In addition, the light control logic AND and OR gates based on a-Ga2O3 thin-film phototransistors were realized by utilizing two light spikes as logic input signals. Our work demonstrates that the a-Ga2O3 thin-film phototransistors have great potential in large area photosensitive circuits with high detection sensitivity and high signal-to-noise ratio.