Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 78: Graphene: Preparation and characterization I (O, jointly with HL, TT)

HL 78.9: Vortrag

Donnerstag, 14. März 2013, 12:30–12:45, H17

Support restructuring during graphene growth on Cu foils triggers the formation of non flat membranes — •Jürgen Kraus¹, Sebastian Böcklein², Robert Reichelt¹, Benito Santos³, Tevfik O. Mentes³, Andrea Locatelli³, and Sebastian Günther¹ — ¹Technische Universität München Chemie Department, D-85748 Garching — ²Ludwig-Maximilians-Universität, D-81377 München — ³Sincrotrone Trieste, I-34149 Trieste - Basovizza

Meanwhile the growth of single crystalline graphene flakes on Cu foils at a mm-length scale can be achieved, which provides a potential source for high quality graphene. On the other hand, the g-Cu system still suffers from certain inherent defects: during graphene growth sequences of inclined Cu facets form which are visible in scanning electron microscopy (SEM) images as stripes and which have been observed as well applying atomic force microscopy (AFM) and scanning tunneling microscopy (STM). Since the graphene follows the morphology of the underlying Cu foil the support restructuring leads to the formation of so called nanorippled graphene which persists even if the graphene is transferred on a flat Si wafer. In our study, we identified a sequence of such Cu facets after graphene growth on a Cu foil using low energy electron microscopy (LEEM) and show why the graphene cannot flatten when removed from the support. In addition, we were able to prepare graphene membranes by the local electrochemical removal of the Cu foil underneath the grown graphene. We show that the resulting membranes are exact replicas of the former morphology of the Cu foil during growth, i.e. they are non flat membranes.