Spectrally Programmable Spin‐Polarized Photocurrents in WSe 2 –NiPS 3 Magnetic van der Waals Heterostructures

Abstract

ABSTRACT Efficient generation and control of spin‐polarized currents in semiconductors remain central challenges for spin‐based electronics, particularly due to impedance mismatch and the reliance on magnetic fields or ferromagnetic contacts. Here, we introduce a materials platform for spectrally programmable spin transport based on a van der Waals (vdW) heterostructure combining the antiferromagnetic semiconductor NiPS 3 with WSe 2 . In a p–n diode architecture, circularly polarized excitation produces pronounced photoconductive resonances with spin‐polarization reaching 80% near the Néel temperature and persisting at ≈30% at room temperature. Remarkably, selected spectral bands retain their polarization sign across the magnetic phase transition, evidencing robust, spectrally protected spin‐polarized current generation. Polarization‐resolved photogalvanic measurements reveal a dominant circular injection‐current mechanism, confirming spin‐polarized carrier transport. First‐principles calculations show that an applied electric field induces interfacial hybridization and spin‐layer locking, giving rise to localized symmetry breaking and enhanced optical absorption while preserving global time‐reversal symmetry. These results establish spectral tuning of excitation as a new control knob for spin transport, enabling spin‐current generation without magnetic fields or polarization switching. Our findings position magnetic vdW heterostructures as a versatile platform for opto‐spintronic functionality and spectrally programmable spintronic devices.