High performance solar-blind UV detector based on Hf0.38Sn0.62O2 epitaxial film

In this work, high-quality SnO2 and Hf0.38Sn0.62O2 thin films were grown on c-plane sapphire substrates by pulsed laser deposition for a comparative study. The optical and electrical tests show that Hf doping leads to significantly increased bandgap and resistivity of the HfSnO2 alloy as compared to SnO2. Then, SnO2- and Hf0.38Sn0.62O2-based UV detectors were fabricated and compared. The Hf0.38Sn0.62O2 film-based detector exhibits an excellent performance. Its dark current is as low as 0.2 pA under 20 V, and the rise/decay response time is as short as 69 ms/50 ms. The cut-off wavelength and the rejection ratio are 290 nm and 4100, respectively. Our work demonstrates that the Hf0.38Sn0.62O2 ternary alloy compound semiconductor has great potential for applications in solar-blind ultraviolet detections.