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 MoWSe4 is elucidated through Raman spectroscopy under linearly polarized excitation, exhibiting a distinct periodic variation in intensity. This study represents the first demonstration of MoWSe4’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 MoWSe4 and MoSe2. MoWSe4 and MoSe2 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 MoSe2/MoWSe4 photodetector exhibits stable and repeatable switching behavior and can be operated with a responsivity of 15 A/W, a detectivity of 5.53 × 1010 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.