Self-filtering narrowband perovskite photodetector with ultra-narrowband and high spectral rejection ratio

Narrowband photodetectors have broad application prospects in many fields where only a range of specific wavelengths light needs to be detected. However, the current narrowband detectors some disadvantages, such as integration is difficult, full width at half-maximum not narrow enough, and spectral rejection ratio ideal (≤20). Here, we present self-filtering photodetector based on MAPbX3 single crystals with very response 15 nm half maximum. It also shows high responsivity (∼100 mA/W) (∼300). What more, spectrum can tuned within certain (from 440 560 nm) by varying halide composition thus its bandgap. This provides new design paradigm for photodetectors.