Self-trapped state enabled filterless narrowband photodetections in 2D layered perovskite single crystals

Filterless narrowband photodetectors can realize color discrimination without filter or bulk spectrometer, thus greatly reducing the system volume and cost for many imaging applications. Charge collection narrowing has been demonstrated to be a successful approach to achieve filterless narrowband photodetections; nevertheless, it sacrifices the sensitivity of the photodetectors. Here we show a highly tunable narrowband photodetector based on two-dimensional perovskite single crystals with high external quantum efficiency (200%), ultralow dark current (10 −12 A), and high on–off ratio (10 3 ). The spectral response of the narrowband photodetectors can be continuously tuned from red to blue with all full-width at half-maximum