engleski

Graphene flakes growth study by ARPES

A well established route for the large-scale production of graphene is chemical vapor phase deposition (CVD) growth on various metal substrates [1]. However, in order to obtain highly oriented graphene cov- ering the entire Ir(111) surface one needs to combine the temperature programmed growth (TPG) with CVD [2]. Moreover, by using just the TPG procedure, it is possible to grow graphene fl akes of various aver- age sizes, depending on the growth parameters used. The overall area of Ir(111) sample covered with fl akes after each TPG cycle is always the same, regardless of the temperature [3]. Here we report a study of graphene fl akes obtained by ethene decomposition on Ir(111) using the TPG procedure at various temperatures. As the decomposition temperature of the preadsorbed ethene increases, the average size of the flakes increases as well. Based on angle- resolved photoemission spectroscopy (ARPES), in particular the Dirac cone intensity analysis, we characterise graphene fl akes on Ir(111) of varying sizes and compare these results with known STM and XPS data. [1] X. Li et al., Science 324, 1312 (2009) [2] R. von Gastel et al., Appl. Phys. Lett. 95, 121901 (2009) [3] J. Coraux et al., New J. Phys. 11, 023006 (2009)

graphene, epitaxial growth, iridium, Dirac cone

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