Surface-induced vertical alignment of self-assembled supramolecular columns of large polycyclic aromatic hydrocarbons and porphyrins

• Ordered films of polycyclic aromatic hydrocarbons (PAHs) and porphyrins with functional (e.g. thiophene) side-groups are good candidates for (opto-)electronic applications where fast charge separation and transport are required. Such highly ordered thin films of PAHs, including discotic hexa-peri-hexabenzocoronene (HBC) and C-132-C-16,C-4, as well as brominated functionalized porphyrin molecules have been grown from solutions on semi-metallic molybdenum disulfide substrates and characterized by angle-resolved valence band photoelectron spectroscopy. A vertical growth of self-assembled supramolecular columns perpendicular to the basal plane of the substrate along with their lateral ordering on the surface has been achieved. Annealing made it possible to increase the structural order in the HBC columns, with molecules positioned at a regular offset from the columnar axis. This permitted the formation of extended pi-electronic states with a bandwidth of at least 0.1-0.2 eV at room temperature. (C) 2004 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

ordered films

hexa-peri-hexabenzocoronene

self-assembled supramolecular columns

TECHNOLOGY

TEKNIKVETENSKAP

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