Two-dimensional van der Waals electrical contact to monolayer MoSi$_2$N$_4$

TL;DR

This study investigates the electronic properties of van der Waals heterostructures involving monolayer MoSi$_2$N$_4$ with graphene and NbS$_2$, revealing ultralow Schottky barriers and tunable contacts for advanced nanoelectronics.

Contribution

It provides the first detailed theoretical analysis of electrical contacts to MoSi$_2$N$_4$, highlighting tunability and ultralow barriers crucial for device design.

Findings

MoSi$_2$N$_4$/NbS$_2$ contact has ultralow Schottky barrier height

MoSi$_2$N$_4$/graphene contact can be modulated by interlayer distance and electric fields

Insights into 2D electrical contact physics for MoSi$_2$N$_4$

Abstract

Two-dimensional (2D) MoSi$_2$N$_4$ monolayer is an emerging class of air-stable 2D semiconductor possessing exceptional electrical and mechanical properties. Despite intensive recent research efforts devoted to uncover the material properties of MoSi$_2$N$_4$, the physics of electrical contacts to MoSi$_2$N$_4$ remains largely unexplored thus far. In this work, we study the van der Waals heterostructures composed of MoSi$_2$N$_4$ contacted by graphene and NbS$_2$ monolayers using first-principle density functional theory calculations. We show that the MoSi$_2$N$_4$/NbS$_2$ contact exhibits an ultralow Schottky barrier height (SBH), which is beneficial for nanoelectronics applications. For MoSi$_2$N$_4$/graphene contact, the SBH can be modulated via interlayer distance or via external electric fields, thus opening up an opportunity for reconfigurable and tunable nanoelectronic devices. Our findings provide insights on the physics of 2D electrical contact to MoSi$_2$N$_4$, and shall offer a critical first step towards the design of high-performance electrical contacts to MoSi$_2$N$_4$-based 2D nanodevices.