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), I_on/I_off (71, 365 nm, 25 mW/cm²), rise/decay time (τ_rise = 0.0475 s and τ_decay = 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.