Ultrahigh Polarization Sensitivity via Bias‐Modulable Twisted Heterojunction Photodetectors With AoLP Detection and Polarity Reversal

Abstract

ABSTRACT Polarization‐sensitive photodetection provides a critical degree of freedom for multidimensional optical information processing; however, achieving both high polarization selectivity and direct extraction of the angle of linear polarization (AoLP) within a single compact device remains a significant challenge. Here, we report a photodetector based on twisted Ta 2 NiSe 5 /MoSe 2 /Ta 2 NiSe 5 van‐der‐Waals heterostructure with dual junctions and oppositely oriented built‐in fields. The bias‐driven carrier competition mechanism enables enhanced polarization selectivity, yielding high polarization ratios of 23.1, 21.0, and 12.5 at 405, 638, and 808 nm, respectively, with an 11 µs response time. Furthermore, distinct from conventional intensity‐based detection, the dual‐channel photocurrents establish an intrinsic mapping between polarization states and electrical‐phase space, enabling direct extraction and imaging of AoLP within a single device, without external optics. The device also shows wavelength‐dependent dichroic inversion from visible (405 nm) to near‐infrared (808 nm), enabling orthogonal polarization responses. Leveraging this mechanism, we further demonstrate polarization–spectral multiplexed imaging, multi‐channel optical communication, and ∼99% accurate information decoding via a dual‐channel neural network, as well as a “two‐shot” polarization imaging strategy for low‐contrast enhancement. This work provides a filter‐free approach to polarization‐resolved photodetection, and opens a new avenue toward reconfigurable and multifunctional polarization optoelectronic devices.