Fast Response Solar-Blind Photodetector with a Quasi-Zener Tunneling Effect Based on Amorphous In-Doped GaO Thin Films.

A high-performance solar-blind photodetector with a metal-semiconductor-metal structure was fabricated based on amorphous In-doped GaO thin films prepared at room temperature by radio frequency magnetron sputtering. The photodetector shows a high responsivity (18.06 A/W) at 235 nm with a fast rise time (4.9 μs) and a rapid decay time (230 μs). The detection range was broadened compared with an individual GaO photodetector because of In doping. In addition, the uneven In distribution at different areas in the film results in different resistances, which causes a quasi-Zener tunneling internal gain mechanism. The quasi-Zener tunneling internal gain mechanism has a positive impact on the fast response speed and high responsivity.