Growth of graphene underlayers by chemical vapor deposition
Mopeli Fabiane,
Saleh Khamlich,
Abdulhakeem Bello,
Julien Dangbegnon,
Damilola Momodu,
A. T. Charlie Johnson,
Ncholu Manyala
Affiliations
Mopeli Fabiane
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
Saleh Khamlich
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
Abdulhakeem Bello
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
Julien Dangbegnon
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
Damilola Momodu
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
A. T. Charlie Johnson
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
Ncholu Manyala
Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028, South Africa
We present a simple and very convincing approach to visualizing that subsequent layers of graphene grow between the existing monolayer graphene and the copper catalyst in chemical vapor deposition (CVD). Graphene samples were grown by CVD and then transferred onto glass substrates by the bubbling method in two ways, either direct-transfer (DT) to yield poly (methyl methacrylate) (PMMA)/graphene/glass or (2) inverted transfer (IT) to yield graphene/PMMA/glass. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to reveal surface features for both the DT and IT samples. The results from FE-SEM and AFM topographic analyses of the surfaces revealed the underlayer growth of subsequent layers. The subsequent layers in the IT samples are visualized as 3D structures, where the smaller graphene layers lie above the larger layers stacked in a concentric manner. The results support the formation of the so-called “inverted wedding cake” stacking in multilayer graphene growth.
