Controlled Electrochemical Deposition of Large‐Area MoS2 on Graphene for High‐Responsivity Photodetectors

Controllable creating of wafer‐scale homogeneous vertical or parallel 2D heterostructures with low cost by the van der Waals stacking or covalently bonded stitching of 2D layered materials, such as graphene, hexagonal boron nitride, and transition‐metal dichalcogenides, is of great challenge. In this paper, a new green growth strategy for the fabrication of high‐quality large‐area and low‐cost vertical MoS2/graphene heterostructures has been successfully demonstrated via electrochemical deposition in water solution, followed by an annealing process in chemical vapour deposition system for the first time. The vertical MoS2/graphene heterostructures have been systematically investigated by the combined use of Raman spectroscopy, atomic force microscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. This simple, reliable, and environmentally friendly growth strategy on conducting monolayer graphene in a controlled manner opens up a new way for producing low‐cost, large‐area, and high‐quality vertical MoS2/graphene heterostructures, which have promising applications not only in electronics and optoelectronics but also in the fields of catalysis and renewable energy. Centimeter‐size and homogeneous vertical MoS2/graphene heterostructures have been successfully fabricated in a controlled manner of thickness (5–150 nm) via environmentally friendly electrochemical deposition of MoS2 on conducting graphene electrodes in the aqueous solution of ammonium tetrathiomolybdate (NH4)2MoS4, followed by a vacuum annealing process in the atmosphere of Ar and H2 without additional sulfur.