Molecular beam growth of graphene nanocrystals on dielectric substrates

TL;DR

This paper reports the successful growth of graphene nanocrystals on dielectric substrates using molecular beam techniques, with characterization confirming high-quality sp2 carbon structures and the influence of substrate roughness on morphology.

Contribution

It introduces a novel molecular beam growth method for graphene nanocrystals on various dielectric substrates, demonstrating control over quality and morphology.

Findings

Higher quality graphene nanocrystals are formed at lower growth rates.

Surface roughness influences the morphology of the nanocrystals.

Raman and NEXAFS confirm the sp2 hybridized hexagonal lattice.

Abstract

We demonstrate the growth of graphene nanocrystals by molecular beam methods that employ a solid carbon source, and that can be used on a diverse class of large area dielectric substrates. Characterization by Raman and Near Edge X-ray Absorption Fine Structure spectroscopies reveal a sp2 hybridized hexagonal carbon lattice in the nanocrystals. Lower growth rates favor the formation of higher quality, larger size multi-layer graphene crystallites on all investigated substrates. The surface morphology is determined by the roughness of the underlying substrate and graphitic monolayer steps are observed by ambient scanning tunneling microscopy.