Modeling and Designing Superlubricating and Low-Resistance van der Waals Heterostructures in Graphene/NbSe2

Abstract

Sliding superslip based on a two-dimensional (2D) material system has a very low friction coefficient, which shows great application potential. In the fields of high-performance micro- and nanoelectronic devices such as nanoelectromechanical system/microelectromechanical systems switches, logic devices, transistors and sensors, and traditional electrical contact devices, most of these applications require both low friction and ultrahigh interface conductivity. However, there is an inherent contradiction between low friction and high conductivity: reducing friction usually requires weakening the interfacial electron coupling, whereas reducing contact resistance requires strengthening the interfacial electron coupling to reduce the tunneling barrier. Here, we propose an effective method to obtain low friction and high conductivity at the sliding van der Waals interface. A metal–2D material–metal contact system was constructed by introducing a graphene/NbSe₂ van der Waals heterostructure at the electrical contact interface. Compared with that of the NbSe₂/NbSe₂ homojunction, the sliding energy barrier of the interface was successfully reduced by more than 1 order of magnitude, and the electrical contact interface is superlubric. In addition, by using Ti as the contact metal for constructing a sliding electrical contact system while introducing carbon atom vacancies in graphene, the tunneling barrier between the 2D/three-dimensional interface can be greatly reduced without losing the superslippery properties of the friction interface. This discovery provides a theoretical design scheme for new electronic devices and high-performance traditional electric sliding contact devices.