Narrow photoluminescence peak of epitaxial MoS$_2$ on graphene/Ir(111)

TL;DR

This paper demonstrates that epitaxial MoS$_2$ grown on graphene/Ir(111) exhibits a narrow photoluminescence peak due to weak interaction with the substrate, making it promising for optoelectronic applications.

Contribution

It shows that MoS$_2$ on graphene/Ir(111) maintains a narrow PL peak because of minimal substrate interaction, enabling large-area, controlled growth for optoelectronics.

Findings

Narrow 18 meV PL peak observed from MoS$_2$ on graphene/Ir(111)

Weak interaction prevents PL quenching and hybridization

No electronic state hybridization between graphene and MoS$_2$

Abstract

We report on the observation of photoluminescence (PL) with a narrow 18 meV peak width from molecular beam epitaxy grown MoS$_2$ on graphene/Ir(111). This observation is explained in terms of a weak graphene-MoS$_2$ interaction that prevents PL quenching expected for a metallic substrate. The weak interaction of MoS$_2$ with the graphene is highlighted by angle-resolved photoemission spectroscopy and temperature dependent Raman spectroscopy. These methods reveal that there is no hybridization between electronic states of graphene and MoS$_2$ and a different thermal expansion of graphene and MoS$_2$. Molecular beam epitaxy grown MoS2 on graphene is therefore an important platform for optoelectronics which allows for large area growth with controlled properties.