Dirk Obergfell (1), Jannik C. Meyer (1,2), Miroslav Haluska (1), Gerhard Ulbricht (1), Timm Lohmann (1), Jurgen Smet (1), Siegmar Roth (1)
1 Max Planck Institute for Solid State Research, Stuttgart, Germany
2 University of California, Berkeley, US
Graphene sheets and few-layer graphite flakes were investigated by transport measurements, high-resolution transmission electron microscopy (HR-TEM) and Raman spectroscopy. The aim of this study is to combine all three measurements on the very same graphite flake to gain maximum knowledge of electronic, structural and vibrational properties of the sample investigated. Moreover, the analysis of HR-TEM and Raman data enables us to decide whether an apparent graphene flake is a graphite monolayer or rather a stacked multilayer of graphene sheets. Raman studies can be performed on the as-fabricated transport sample, whereas the silicon substrate has to be etched away prior HR-TEM studies. The etching process creates a free-standing graphite flake which is mechanically stabilized by supporting metal structures evaporated before.