Properties of In-Plane Graphene/MoS2 Heterojunctions

TL;DR

This paper provides an atomic-scale analysis of graphene/MoS2 heterojunctions, revealing boundary structures, charge transfer, and Fermi level pinning, with implications for spin-polarized current applications.

Contribution

It offers a detailed atomic-scale understanding of the structural, electronic, and magnetic properties of lateral graphene/MoS2 heterojunctions, highlighting boundary effects and potential spintronic uses.

Findings

Boundary structures depend on chemical conditions.

Charge transfer is localized at the boundary.

Fermi level is pinned by 1D boundary states.

Abstract

The graphene/MoS2 heterojunction formed by joining the two components laterally in a single plane promises to exhibit a low-resistance contact according to the Schottky-Mott rule. Here we provide an atomic-scale description of the structural, electronic, and magnetic properties of this type of junction. We first identify the energetically favorable structures in which the preference of forming C-S or C-Mo bonds at the boundary depends on the chemical conditions. We find that significant charge transfer between graphene and MoS2 is localized at the boundary. We show that the abundant 1D boundary states substantially pin the Fermi level in the lateral contact between graphene and MoS2, in close analogy to the effect of 2D interfacial states in the contacts between 3D materials. Furthermore, we propose specific ways in which these effects can be exploited to achieve spin-polarized currents.