Symmetry-reduction enhanced one-dimensional polarization-sensitive photodetectors for multi-functional applications

Abstract

Due to their intrinsic structural anisotropy, one-dimensional van der Waals (1D vdW) materials can introduce distinct polarization photosensitivity. However, photodetectors based on 1D van der Waals materials generally face challenges such as poor photosensitivity, narrow effective optical windows, and uncompetitive dichroism. Herein, a strong anisotropic 1D vdW Nb₂Pd_1−xSe₅ material is successfully synthesized by chemical vapor transport (CVT). Apart from broadband photoresponse (520 to 1064 nm), the as-fabricated 1D vdW Nb₂Pd_1−xSe₅ photodetector exhibits excellent photoresponse, including a high responsivity (R), specific detectivity (D*), and external quantum efficiency (EQE) of 1590 A W⁻¹, 4 × 10¹¹ jones, and 3 × 10⁵% and an ultrafast response time of ∼2 μs. Impressively, this photodetector exhibits a robust polarization ratio (PR) of up to 14.3, which is believed to be related to the symmetry reduction induced by the partial occupation of Pd sites. Then, image convolutional processing is enabled by configuring appropriate convolution kernels based on the polarization-sensitive photoresponse. Moreover, proof-of-concept multiplexing optical communications and polarization imaging are demonstrated based on the devices. This study provides an additional perspective on the novel application of polarization-sensitive photodetectors based on 1D vdW materials.