Molybdenum Disulfide/Double-Wall Carbon Nanotube Mixed-Dimensional Heterostructures

Mixed-dimensional heterostructures which combine materials with different dimensions have emerged to expand the scope and functionality of van der Waals heterostructures. Here, a direct synthesis method of molybdenum disulfide/double-wall carbon nanotube (MoS₂/DWCNT) mixed-dimensional heterostructures by sulfurating a molten salt, Na₂MoO₄, on a substrate covered with a DWCNT film is reported. The synthesized heterostructures are comprehensively characterized and their stacking order is confirmed to be MoS₂ under the DWCNTs, although the DWCNT film is transferred on the substrate first. Moreover, field-effect transistors based on the heterostructure are fabricated for photodetection, and an abnormal negative photoresponse is discovered due to the strong carrier transfer in the mixed-dimensional heterostructures under light incidence. The MoS₂/DWCNT heterostructure results provide a new approach for the synthesis and applications of mixed-dimensional heterostructures.