Modulating PL and electronic structures of MoS_2/graphene heterostructures via interlayer twisting angle

摘要

Stacking two-dimensional materials into van der Waals heterostructures with distinct interlayer twisting angles opens up new strategies for electronic structure and physical property engineering. Here, we investigate how the interlayer twisting angles affect the photoluminescence (PL) and Raman spectra of the MoS_2/graphene heterostructures. Based on a series of heterostructure samples with different interlayer twisting angles, we found that the PL and Raman spectra of the monolayer M0S2 in these heterostructures are strongly twisting angle dependent. When the interlayer twisting angle evolves from 0° to 30°, both the PL intensity and emission energy increase, while the splitting of the E_(2g) Raman mode decreases gradually. The observed phenomena are attributed to the twisting angle dependent interlayer interaction and misorientation-induced lattice strain between M0S2 and graphene.