Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 9: Graphene I: Structure and Growth (joint session O/TT)

TT 9.5: Vortrag

Montag, 1. April 2019, 11:45–12:00, H24

Understanding the first steps of graphene growth: a study of small carbon clusters on Cu surfaces — •Juan Santiago Cingolani, Mie Andersen, and Karsten Reuter — Chair of Theoretical Chemistry, Technical University of Munich, Germany

It has been shown that high quality single layer graphene can be obtained through chemical vapor deposition on liquid Cu [1]. The role of the liquid surface in carbon nucleation as well as in defect healing is not yet well understood. While a comprehensive description of the growth mechanism would require molecular dynamics (MD) simulations, a first step is to study the precursors for graphene growth and the influence of the surface on them.

We performed a series of density-functional theory (DFT) calculations of carbon clusters of different sizes adsorbed to different Cu facets aiming to shed some light on the effects of the surface on relative stabilities, as well as on experimentally accessible properties such as vibrational frequencies. We also take advantage of the data generated to fit the parameters of density-functional tight binding, a semi-empirical method, which in turn allows us to carry out MD simulations for longer timescales and in larger systems than otherwise accessible through ab initio methods. We then simulate graphene flakes on liquid Cu at different levels of theory to get a clearer picture of what the Cu surface might look like under growth conditions.

[1] L. Tan, M. Zeng, T. Zhang, L. Fu, Nanoscale 7, 9105 (2015).