Tuning interlayer coupling by laser irradiation and broadband photodetection in vertical MoTe2/WS2 vdW heterostructure

van der Waals (vdW) heterostructures constructed by stacking different two dimensional layered materials are extensively utilized in designing novel optoelectronic devices, such as photodetectors and light-emitting diodes. However, the performance of vertical heterostructures is impeded by challenges in effectively achieving interlayer coupling. Here, the systematic demonstration of vertical MoTe2/WS2 vdW heterostructures assembled by a mechanical transfer technique is reported, whereas the interlayer interaction is tuned from weak coupling to strong coupling by laser irradiation. Thereafter, the improved interlayer interaction of heterostructures is characterized by photoluminescence spectroscopy and further confirmed by electrical transport. Moreover, visible-infrared broadband photoresponse is achieved in the vertical stacking with the built-in field generated between MoTe2 and WS2. Thus, the outstanding findings of our experimental approach can facilitate novel two-dimensional devices for the optoelectronics industry.