Low-temperature scanning tunneling microscopy is used to probe, with atomic-scale spatial resolution, the intrinsic luminescence of a van der Waals heterostructure, made of a transition metal dichalcogenide monolayer stacked onto a few-layer graphene flake supported by an Au(111) substrate. Sharp emission lines arising from neutral, charged and localised excitons are reported. Their intensities and emission energies vary as a function of the nanoscale environment of the van der Waals heterostructure, explaining the variability of the emission properties observed with diffraction-limited approaches. Our work paves the way towards understanding and control of optoelectronic phenomena in moir\'e superlattices with atomic-scale resolution.
@article{arxiv.2204.14022,
title = {Tip-induced excitonic luminescence nanoscopy of an atomically-resolved van der Waals heterostructure},
author = {Luis E. Parra López and Anna Rosławska and Fabrice Scheurer and Stéphane Berciaud and Guillaume Schull},
journal= {arXiv preprint arXiv:2204.14022},
year = {2023}
}