Higher-indexed Moiré patterns and surface states of MoTe₂/graphene heterostructure grown by molecular beam epitaxy

Stabilization of the 2H phase of MoTe₂ during molecular beam epitaxy (MBE) growth on graphene terminated 6H-SiC(0001) is highly desirable in order to take advantage of its promising properties in electronic applications. By properly adjusting the conditions, direct growth of the highly crystalline 2H phase of MoTe₂ has been achieved. In such van der Waals heterostructure, the atomically-clean interface between graphene and MoTe₂ permits the electronic coupling between the adjacent layers and the emergence of a high variety of Moiré patterns. In this paper, we investigate a single layer of 2H-MoTe₂ grown on graphene by MBE and we present scanning tunneling microscopy (STM) investigations combined with density functional theory (DFT) calculations and simulations of STM images. Our results show that the STM images of the MoTe₂/graphene heterostructure surprisingly amplify the otherwise weak Moiré potential modulations leading to the appearance of unique higher-indexed Moiré patterns. These patterns are unusually rich with many Fourier-overtones and show a remarkable variety of different applied bias voltages, revealing the complex electronic features of the heterostructure.