Synergistic effects of extrinsic photoconduction and photogating in a short-wavelength ZrS infrared photodetector.

Two-dimensional (2D) material-based photodetectors, especially those working in the infrared band, have shown great application potential in the thermal imaging, optical communication, and medicine fields. Designing 2D material photodetectors with broadened detection band and enhanced responsivity has become an attractive but challenging research direction. To solve this issue, we report a zirconium trisulfide (ZrS) infrared photodetector with enhanced and broadened response with the assistance of the synergistic effects of extrinsic photoconduction and photogating effect. The ZrS photodetectors can detect infrared light up to 2 μm by extrinsic photoconduction and exhibit a responsivity of 100 mA W under 1550 nm illumination. Furthermore, the ZrS infrared photodetectors with an oxide layer show a triple enhanced responsivity due to the photogating effect. Additionally, the infrared imaging capability of the ZrS infrared photodetectors is also demonstrated. This work provides a potential way to extend the response range and improve the responsivity for nanomaterial-based photodetectors at the same time.