Infrared Polarization Photodetector Based on 2D MoSe₂/MoWSe₄ van der Waals Heterojunction

van der Waals heterojunctions based on atomically thin two-dimensional materials have garnered significant attention in optoelectronics due to their unique band alignment and ultrathin morphology. The anisotropy of MoWSe 4 is elucidated through Raman spectroscopy under linearly polarized excitation, exhibiting a distinct periodic variation in intensity. This study represents the first demonstration of MoWSe 4 ’s capability to achieve polarization effects, representing a significant advancement in two-dimensional materials. Here, photovoltaic detectors with infrared and polarization-sensitive optoelectronic functionality are developed based on MoWSe 4 and MoSe 2 . MoWSe 4 and MoSe 2 form a type-II band alignment, resulting in a response in the near-infrared region. The device exhibits broad spectral and bidirectional responses, with a wavelength range spanning from 400 to 1550 nm. The MoSe 2 /MoWSe 4 photodetector exhibits stable and repeatable switching behavior and can be operated with a responsivity of 15 A/W, a detectivity of 5.53 × 10 10 Jones, and an external quantum efficiency of 2879%. These findings provide theoretical and experimental support for advancing infrared polarization-sensitive photodetectors based on two-dimensional materials.