Self-powered broadband RGB imaging photodetector based on air-stabilized Bi2Te3 nanosheets

Room temperature self-powered broadband (RTSPBD) response photodetectors have received considerable attention and are also very helpful in alleviating today's energy and environmental crisis. Herein, bismuth telluride (Bi2Te3) nanosheets were successfully synthesized and assembled into an RTSPBD photodetector. The Bi2Te3 photodetector exhibits excellent response characteristics: wide spectral range, maximum responsivity (10.254 mA/W, 435 nm), photocurrent density (106 μA/cm2), Ion/Ioff (71, 365 nm, 25 mW/cm2), rise/decay time (τrise = 0.0475 s and τdecay = 0.0468 s) and cycling stability. A superior responsivity from the ultraviolet to infrared (UV-IR) region is observed, which is attributed to the fact that the narrow bandgap topological insulating state of Bi2Te3 provides a fast charge transport channel for electrons generated by the photovoltaic effect. In addition, it was found that these devices have potential applications in red-green-blue (RGB) triple primary color imaging. It is anticipated that this work will provide a great promising candidate material for the design and preparation of high-performance RTSPBD photodetection imaging devices in the future.