Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 44: Graphene: Electronic Properties, Structure and Substrate Interaction
O 44.3: Poster
Dienstag, 8. März 2016, 18:15–20:30, Poster E
A bottom-up approach to synthesize graphene nanoribbons on Ru(0001) by chemical vapor deposition — •Ann-Kathrin Henss and Joost Wintterlin — Ludwig-Maximilians-Universität, Munich, Germany
The synthesis of defined graphene nanoribbons is of great interest for future applications due to their tunable band gaps. We have tested a bottom-up approach to synthesize graphene nanoribbons by chemical vapor deposition (CVD) of hydrocarbons on a prestructured Ru(0001) single crystal under ultra high vacuum conditions. The structuring of the substrate was achieved by aluminum deposition at elevated sample temperatures to decorate the step edges of the Ru(0001) surface. A subsequent oxidation step led to the formation of ordered stripes of aluminum oxide along the step edges which are to act as barriers between which graphene could grow in form of nanoribbons. Graphene was grown by CVD using ethylene as a precursor gas at 850∘C and a pressure of 3×10−9 Torr. Scanning tunneling microscopy and Auger electron spectroscopy were used to monitor the synthesis steps. After the graphene growth no ordered structures of aluminum oxide were present on the surface anymore. Hydrogen forming during the decomposition of ethylene was found to reduce the aluminum oxide to metallic aluminum, which is no longer a growth barrier for graphene.