First-Principles Study of Hybrid Graphene and MoS$_2$ Nanocomposites

TL;DR

This study uses first-principles calculations to explore the electronic, electrical, and optical properties of hybrid graphene and MoS$_2$ nanocomposites, revealing tunable doping and enhanced optical features for device applications.

Contribution

It provides a detailed theoretical analysis of hybrid G/MoS$_2$ nanocomposites, highlighting tunable doping and optical improvements, which were not previously characterized.

Findings

Weak van der Waals interactions preserve intrinsic properties.

Electric fields enable tunable p-type doping of graphene.

Enhanced optical properties suggest potential for photovoltaic devices.

Abstract

Combining the electronic properties of graphene and molybdenum disulphide (MoS$_2$) monolayers in two-dimensional (2D) ultrathin hybrid nanocomposites have been synthesized experimentally to create excellent electronic, electrochemical, photovoltaic, photoresponsive and memory devices. Here, first-principles calculations are performed to investigate the electronic, electrical and optical properties in hybrid G/MoS$_2$ and G/MoS$_2$/G nanocomposites. It turns out that weak van der Waals interactions dominate between graphene and MoS$_2$ with their intrinsic electronic properties preserved. Interestingly, tunable p-type doping of graphene is very easy to achieve by applying electric fields perpendicular to hybrid G/MoS$_2$ and G/MoS$_2$/G nanocomposites, because electrons can easily transfer from the Dirac point of graphene to the conduction band of MoS$_2$ due to the work function of graphene close to the electronic affinity of MoS$_2$. Vertical electric fields can generate strong p-type but weak n-type doping of graphene, inducing electron-hole pairs in hybrid G/MoS$_2$/G sandwiched nanocomposites. Moreover, improved optical properties in hybrid G/MoS$_2$ and G/MoS$_2$/G nanocomposites are also expected with potential photovoltaic and photoresponsive applications.