Analysis of nanostructured blue light-emitting p-6P films on mica

Blue light-emitting aggregates of para-hexaphenyl molecules ('needles') are generated via dipole-assisted self assembly on single crystalline mica substrates. By applying atomic force microscopy and fluorescence microscopy we deduce size distributions as well as height-width correlations of individual aggregates. We find growth of densely-packed, needle-like structures even in the initial growth stage at low surface temperatures. However, long (up to one millimeter) and sparsely distributed, individually addressable needles grow only at high substrate temperatures and low adsorption rates. For a given sample at constant deposition conditions the height of the needles seems to be independent of width. This opens up the possibility to control the morphology of individual nanostructured aggregates.

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