Dresden 2020 – wissenschaftliches Programm
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TT 72.3: Vortrag
Freitag, 20. März 2020, 11:00–11:15, GER 37
Experimental access to thermodynamics and kinetics predicting the CVD growth of graphene on Cu — •Paul Leidinger, Jürgen Kraus, and Sebastian Günther — TUM, Dept. Chemie, Lichtenbergstr. 4, D-85748 Garching
Most Graphene growth recipes by chemical vapor deposition (CVD) on copper in a reactive CH4/H2 atmosphere are results of parameter variations optimized by trial and error. Many existing growth models described in the literature are qualitative or contain phenomenological parameters to describe the growth process. In our study, we aim at analyzing the key processes during CVD at 900-1050 ∘C while maintaining the defined geometry of a growing graphene flake surrounded by graphene free copper. For this purpose, it is essential to control the flake nucleation before and, more importantly, during the entire CVD growth. Systematic variation of the CVD parameters provides the experimental data used to formulate a kinetic model which predicts the graphene growth velocity as function of the chosen mass action constant Q. Determining experimentally the thermodynamic equilibrium of the CH4 decomposition reaction enables us to use the equilibrium as reference point to which any chosen CVD parameter set can be related quantitatively. With experimental validation of our growth model we can understand both, the thermodynamics and kinetics of graphene growth on copper. Furthermore, we can also predict the growth rate of single graphene flakes formed during any CVD experiment on copper at high precision.