Solar-blind deep-ultraviolet photodetectors based on solution-synthesized quasi-2D Te nanosheets

Solar-blind deep ultraviolet (DUV) photodetectors with high responsivity (R) and fast response speed are crucial for practical applications in astrophysical analysis, environmental pollution monitoring, and communication. Recently, 2D tellurium has emerged as a potential optoelectronic material because of its excellent photoelectric properties. In this study, solar-blind DUV photodetectors are demonstrated based on solution-synthesized and air-stable quasi-2D Te nanosheets (Te NSs). An R of 6.5 × 104 A/W at 261 nm and an external quantum efficiency (EQE) of higher than 2.26 × 106% were obtained, which are highest among most other 2D material-based solar-blind DUV photodetectors. Moreover, the photoelectric performance of the quasi-2D Te-based photodetector exhibited good stability even after ambient exposure for 90 days without any encapsulation. These results indicate that quasi-2D Te NSs provide a viable approach for developing solar-blind DUV photodetectors with ultrahigh R and EQE.