Filterless Polarization‐Sensitive 2D Perovskite Narrowband Photodetectors

Abstract Polarization‐sensitive narrowband photodetectors can respond to a narrow spectral range of light together with the ability to sense the polarization of light. Traditionally, expensive filters combined with polarizers are utilized to realize the polarization‐sensitive narrowband photodetections. To reduce the cost and simplify optical system, here a polarization‐sensitive narrowband photodetector based on 2D perovskite single crystals without any additional optical components is reported. The photodetector shows a linear dichroic ratio of 1.56 at 552 nm under the oblique incident angle of 45° and the full width at half maximum of 20 nm. Moreover, the photodetector exhibits a high external quantum efficiency of 120% and a peak specific detectivity of 1.23 × 10 10 Jones under the normal illumination. This polarization‐sensitive narrowband photoresponse can be ascribed to the charge collection narrowing mechanism assisted by the enhanced self‐trapped states in 2D perovskites and the large anisotropic crystal structure between different crystal directions. In particular, the device configuration is specially designed so that the absorption anisotropy takes place between the in‐plane and out‐of‐plane directions and photogenerated carriers transport along the in‐plane direct to avoid the large organic barrier along the out‐of‐plane direction, resulting in the polarization‐sensitive narrowband photodetections with high performance.