Higher-indexed Moiré patterns and surface states of MoTe2/graphene heterostructure grown by molecular beam epitaxy
Trung T. Pham, Péter Vancsó, Márton Szendrő, Krisztián Palotás, Roshan Castelino, Mehdi Bouatou, Cyril Chacon, Luc Henrard, Jérôme Lagoute, R. Sporken
Abstract
Abstract Stabilization of the 2 H phase of MoTe 2 during molecular beam epitaxy (MBE) growth on graphene terminated 6 H -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 2 H phase of MoTe 2 has been achieved. In such van der Waals heterostructure, the atomically-clean interface between graphene and MoTe 2 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 2 H -MoTe 2 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 MoTe 2 /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.