Excitons in Epitaxially Grown WS₂ on Graphene: A Nanometer-Resolved Electron Energy Loss Spectroscopy and Density Functional Theory Study.

ABSTRACT: We investigate the excitonic properties of epitaxially grown WS₂ monolayers, bilayers and multilayers on graphene using monochromatic electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope. This material system is particularly attractive for optoelectronic applications, as direct growth from the gas phase offers a scalable route to wafer-sized heterostructures. The combination of nanometer-scale spatial resolution and high spectral quality in EELS allows for a detailed analysis of layer-dependent excitonic features. To complement the experimental results, we perform ab initio simulations based on density functional theory and the Bethe-Salpeter equation. The experimental spectra reveal a systematic redshift of both A and B excitons at the

SUBMITTER: Bergmann M 

PROVIDER: S-EPMC12752690 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature