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

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 In₂Se₃/ReS₂ 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 In₂Se₃ 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 × 10¹³ Jones), and external quantum efficiency (34195%). Additionally, competitive polarization sensitivity across the broad spectrum and imagining capability are observed with In₂Se₃/ReS₂ vdWs heterostructure. This study demonstrates that In₂Se₃/ReS₂ vdWs heterostructure device provides a promising technique for developing high-performance 2D optoelectronic devices with multifunctionalities.