High discrimination infrared polarimetry via intrinsic anisotropic photogating in black phosphorus meta-polarization detectors

Filterless miniaturized polarization photodetectors are essential for next-generation ultracompact optical and optoelectronic systems. However, achieving high polarization discrimination and high sensitivity over a broad wavelength range based on a simple device structure remains difficult. Here, we address this challenge by leveraging a band modulation effect induced by intrinsic anisotropic photogating. We realize a meta-polarization-detector consisting of a black phosphorus (BP) flake partially supported by SiO2 with trap states and partially supported by hexagonal boron nitride (hBN) with almost no trap states. The band distribution and hence the self-powered photocurrent are significantly influenced by light illumination in a polarization dependent manner. The polarization extinction ratio (PER) tending to ∞/−∞ is achieved over the near- to mid-infrared range with high specific detectivity. Further, our device achieves PER = ∞/−∞ under blackbody radiation. The specific polarization angle detectivity reaches 3 × 107 cm Hz0.5 W−1 degree−1. Despite utilizing the photogating effect, the photoresponse times are of the order of microseconds. Our work provides a promising approach for high performance ultracompact polarization photodetectors.