11/11 研究科セミナー（Montanuniversität Leoben: Prof. Dr. C. Teichert）
Graphene as Substrate for Small Organic Molecules
Prof. Dr. Christian Teichert
Institute of Physics, Montanuniversität Leoben, Austria
Crystalline films of conjugated organic semiconductors offer attractive potential for optoelectronic and electronic applications on flexible substrates justifying growth studies of molecules like the rod-like oligophenylene molecule parahexaphenyl (6P) [1,2]. However, these applications require a transparent and flexible electrode material; and here the novel material graphene (Gr) comes into play. Since small conjugated molecules like the rod-like oligophenylene molecule parahexaphenyl (6P) fits well to the hexagonal structure of graphene, growth of 6P on Gr can be expected in a lying configuration.
As demonstrated recently by in situ by low-energy electron microscopy, 6P grows at 240 K indeed in a layer-by-layer mode with lying molecular orientation on Ir(111) supported graphene . Islands start at Gr wrinkles. At higher temperatures, needle-like 6P crystallites are observed . Also on exfoliated graphene, such needles develop with discrete orientations defined by the Gr lattice as was detected by atomic-force microscopy (AFM) . The required robustness of Gr for device applications was demonstrated by AFM based dynamic plowing in conjunction with Kelvin probe force microscopy .
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