Linearly/Circularly Polarization-Sensitive Photodetector Enabled by Vertically Stacked P-Semimetal-N (PMN) Dual Schottky Junction for Information Transmission

On-chip integrated photodetectors capable of distinguishing both linear and circular polarization states present a promising pathway toward ultracompact full-Stokes polarimeters. Weyl semimetals inherently discriminate linearly polarized light (LPL) and circularly polarized light (CPL) due to broken inversion symmetry and topological bands, eliminating the need for external waveplates found in conventional designs. However, single-component Weyl semimetals suffer from prohibitively high dark current and a high carrier recombination rate that overwhelm polarization-dependent photocurrents. Here, we demonstrate a dual van der Waals Schottky junction comprising a p-type WSe2/Td-MoTe2 semimetal/n-type MoS2 heterojunction. This heterojunction architecture uniquely constructs two opposing built-in electric fields oriented vertically within the Td-MoTe2 channel layer, thereby reducing the dark current and enhancing the collection efficiency. Compared to the original Td-MoTe2, the photodetector exhibited a suppression of dark current at zero bias by 7 orders of magnitude (from 10–6 A down to 10–13 A). It achieved a light-on-to-off ratio of 104, enabling low-noise detection. Moreover, our device facilitates both linearly polarized discrimination and observable circularly polarized sensitivity. Leveraging these dual-polarization sensitivities, we demonstrated high-contrast polarization imaging, linearly/circularly polarized light communication, and dual-wavelength image encryption processing. This work establishes 2D van der Waals anisotropic heterojunctions as a platform for highly sensitive, energy-efficient, on-chip integrated full-Stokes photodetection.