Infrared polarization-sensitive photodetectors have attracted considerable interest for night vision, remote sensing and imaging applications. Traditional bulk infrared photodetectors suffer from integration challenges and high-power consumption induced by the cryogenic cooling requirement. Here, we demonstrate a tunneling-dominant triple-junction broadband polarization-sensitive photodetector based on a van der Waals heterostructure, operating from the near-infrared (NIR) to the long-wave infrared (LWIR) band. The device exhibits low noise current, low power consumption and high detectivity. Benefiting from the photogating-assisted tunneling, it reaches a responsivity of ~ 8 × 10