Electron redistribution and energy transfer in graphene/MoS₂ heterostructure

In this letter, van der Waals heterostructures (vdWHs) assembled by molybdenum disulfide (MoS₂) and graphene monolayers are used as an experimental prototype to study the interaction between two-dimensional (2D) semiconducting and semimetal materials. The electron redistribution and energy transfer in graphene/MoS₂ vdWHs are demonstrated by the combination of electrical measurements (Dirac-point shift) and Raman analyses. In graphene, the linear dispersive Dirac fermions can resonate with various-frequency “photons,” which “emit” from optically active MoS₂ by the recombination of in-plane excitons. The experimental finding suggests that the photon-induced charge separation and accumulation might be in a low degree, thus affecting the performance of semiconductor/graphene-based 2D optoelectronic devices.