Self-Driven Perovskite Narrowband Photodetectors with Tunable Spectral Responses.

Narrowband photodetectors with tunable spectral responses are highly desirable for applications in image sensing, machine vision, and optical communication. Herein, a filterless and self-driven perovskite narrowband photodetector (PNPD) based on the defect-assisted charge collection narrowing (CCN) mechanism is reported, which is enabled by a high-quality thick perovskite film. By adjusting the halide component of the perovskite layer, the bandgap is successfully modulated and the corresponding narrowband photodetectors show a wide spectral response range from the red to the near-infrared (NIR), all with full-widths at half maximum (FWHMs) below 30 nm. Specifically, the methylammonium lead iodide (MAPbI3 ) narrowband photodetector exhibits a characteristic detection peak at 800 nm with a very low noise current of ≈0.02 pA Hz-1/2 , a high specific detectivity up to 1.27 × 1012 Jones, and a fast response speed with rise/fall time of 12.7/6.9 µs. Impressively, these values are among the highest of their kind reported previously, and allow demonstration of narrowband imaging. The excellent performance of self-driven PNPDs lights up their prospect in high-efficiency optoelectronic devices without external power sources.