The band alignments modulation of g–MoTe2/WTe2 van der Waals heterostructures

Searching for novel two-dimensional (2D) materials based nanoscale electronic devices is a hot topic in the current research. A modulation of materials’ specific physical properties by altering external conditions has long been used. There are a variety of routes to improve the specific behavior of materials. In this paper, the structural, electronic, and the corresponding variational characteristics of the graphene(g)-MoTe2/WTe2 heterointerfaces are studied in detail based on ab initio calculations with nonlocal van der Waals (vdW) corrections. We performed research on the band alignments of g–MoTe2/WTe2 contacts and a concise routine to reduce the Schottky barrier and obtain Ohmic contact. The results predict a barrier height of 62 meV and 280 meV for g–MoTe2/WTe2, respectively, in a neutral state. In the applied electric field, the corresponding Schottky barriers can be effectively tuned by various electric fields. The height of the barrier further decreases to 0 under − 0.02/0.16 V/Å and − 0.06/0.08 V/Å for g–MoTe2/WTe2, respectively, and the numerical value of the barrier and the corresponding Schottky type can be regulated in a flexible way. Additionally, theoretical calculation results also demonstrate that g–MoTe2 has a smaller Fermi level pinning effect than g–WTe2, which plays a significant role in the fabrication of novel transistors based 2D materials and it should be a better choice for FETs application.