Achieving a superlubricating ohmic sliding electrical contact via a 2D heterointerface: a computational investigation

Abstract

Simultaneously achieving low friction and fine electrical conductance of sliding electrical contacts is a crucial factor but a great challenge for designing high-performance microscale and nanoscale functional devices. Through atomistic simulations, we propose an effective design strategy to obtain both low friction and high conductivity in sliding electrical contacts. By constructing graphene(Gr)/MoS₂ two-dimensional (2D) heterojunctions between sliding Cu surfaces, superlubricity can be achieved with a remarkably lowered sliding energy barrier as compared to that of the homogeneous MoS₂ lubricated Cu contact. Moreover, by introducing vacancy defects into MoS₂ and substituting Cu with active metal Ti, the Schottky and tunneling barriers can be substantially suppressed without losing the superlubricious properties of the tribointerface. Consequently, a high conductivity ohmic contact with low sliding friction could be realized in our proposed Ti–MoS_1.5–Gr–Ti system, which provides a potential strategy for tackling the well-known dilemma for high performance sliding electrical contacts.