Using polycyclic aromatic hydrocarbons for graphene growth on Cu(111) under ultra-high vacuum

Klein, Benedikt P.; Stoodley, Matthew A.; Edmondson, Matthew; Rochford, Luke A.; Walker, Marc; Sattler, Lars; Weber, Sebastian M.; Hilt, Gerhard; Williams, Leon B. S.; Lee, Tien-Lin; Saywell, Alex; Maurer, Reinhard J.; Duncan, David A.

Abstract

Ultra-high vacuum deposition of the polycyclic aromatic hydrocarbons azupyrene and pyrene onto a Cu(111) surface held at a temperature of 1000 K is herein shown to result in the formation of graphene. The presence of graphene was proven using scanning tunneling microscopy, x-ray photoelectron spectroscopy, angle-resolved photoemission spectroscopy, Raman spectroscopy, and low energy electron diffraction. The precursors, azupyrene and pyrene, are comparatively large aromatic molecules in contrast to more commonly employed precursors like methane or ethylene. While the formation of the hexagonal graphene lattice could naively be expected when pyrene is used as a precursor, the situation is more complex for azupyrene. In this case, the non-alternant topology of azupyrene with only 5- and 7-membered rings must be altered to form the observed hexagonal graphene lattice. Such a rearrangement, converting a non-alternant topology into an alternant one, is in line with previous reports describing similar topological alterations, including the isomerization of molecular azupyrene to pyrene. The thermal synthesis route to graphene, presented here, is achievable at comparatively low temperatures and under ultra-high vacuum conditions, which may enable further investigations of the growth process in a strictly controlled and clean environment that is not accessible with traditional precursors.

• Journal Article Type: Article
• Acceptance Date: Oct 23, 2022
• Online Publication Date: Nov 10, 2022
• Publication Date: Nov 7, 2022
• Deposit Date: Nov 14, 2022
• Publicly Available Date: Nov 15, 2022
• Journal: Applied Physics Letters
• Print ISSN: 0003-6951
• Electronic ISSN: 1077-3118
• Publisher: AIP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 121
• Issue: 19
• Article Number: 191603
• DOI: https://doi.org/10.1063/5.0122914
• Public URL: https://nottingham-repository.worktribe.com/output/13465406
• Publisher URL: https://aip.scitation.org/doi/10.1063/5.0122914