Abstract 2D van der Waal (vdWs) heterostructures present unique optoelectronic characteristics, making them favorable layer structures for constructing promising optoelectronic devices with multifunctional applications. Nevertheless, as a result of significant interface recombination of the photogenerated electron‐hole pairs and the presence of various absorption edges within constituent layers, they are prone to experiencing low carrier collection efficiency. In this work, a combined theoretical and experimental investigation are presented on the In 2 Se 3 /ReS 2 vdWs heterostructure, aimed at developing high‐performance and broadband photodetector with multifunctionalities. In theoretical investigations, it is observed that, by adjusting the polarization states (+P to −P) in the In 2 Se 3 layer, band alignment can be effectively tuned from type‐I to type‐II, providing a narrow bandgap of ≈0.65 eV, which is beyond that of their individual constituents. As a photodetector, the device shows broadband photoresponse ranging from 532 to 1550 nm with ultrahigh responsivity (99.36 AW −1 ), detectivity (3.5 × 10 13 Jones), and external quantum efficiency (34195%). Additionally, competitive polarization sensitivity across the broad spectrum and imagining capability are observed with In 2 Se 3 /ReS 2 vdWs heterostructure. This study demonstrates that In 2 Se 3 /ReS 2 vdWs heterostructure device provides a promising technique for developing high‐performance 2D optoelectronic devices with multifunctionalities.

Interlayer Charge Transition and Broadband Polarization Photodetection and Imaging Based on In2Se3/ReS2 van der Waals Heterostructure