Ultrahigh Detectivity and Wide Dynamic Range Ultraviolet Photodetectors Based on Bi_xSn_1-xO₂ Intermediate Band...

The ultraviolet (UV) photodetectors have significant applications different fields. High detectivity, high responsivity and wide active area are required to probe a weak UV light in actual ambient. Unfortunately, most practical UV photoconductors based on wide bandgap semiconductor films can hardly have both a high responsivity and a low dark current density. In this study, the intermediate band engineering in semiconductor has been proposed try to solve this problem. The intermediate band UV photodetectors based on Bi_xSn_1-xO₂ (0.017 < x < 0.041) films show a detectivity of 6.1 × 10¹⁵ Jones at 280 nm and a quantum efficiency of 2.9 × 10⁴ %. The dynamic range is 195 dB, which is much higher than other UV photodetector. The recovery time is about 1 s after exposing device into ethanol steam. Our results demonstrate that the intermediate band semiconductor Bi_xSn_1-xO₂ films can serve as a high performance UV photodetector.