Amorphous Ga2O3 Thin-Film Phototransistors for Imaging and Logic Illustration

Amorphous Ga2O3 (a-Ga2O3) thin-film phototransistors were fabricated by sputtering and achieved excellent solar-blind detection properties with superhigh responsivity of 2.0 $\times \,\,10^{{5}}\,\,\text{A}\cdot \text{W}^{-{1}}$ , ultrahigh detectivity of 4.9 $\times \,\,10^{{18}}$ Jones, high external quantum efficiency of 9.9 $\times \,\,10^{{7}}$ %, and high photo-to-dark current ratio of 2.9 $\times \,\,10^{{8}}$ . 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 $\beta $ -Ga2O3 phototransistors. A 10 $\times10$ 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.