Self-organization of para-sexiphenyl on crystalline substrates

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2005-09, Vol.202 (12), p.2376-2385
• Main Authors: Hlawacek, Gregor, Teichert, Christian, Andreev, Andrei Yu, Sitter, Helmut, Berkebile, Stephen, Koller, Georg, Ramsey, Michael, Resel, Roland
• Format: Article
• Language: English
• Subjects: 68.37.Ps; 68.55.Ac; 68.55.Jk; 81.10.Aj; 81.15.-z; 81.16.Dn; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 1862-6300; 0031-8965; 1862-6319; 1521-396X
• DOI: 10.1002/pssa.200521173

The understanding of fundamental growth processes is critical for the fabrication of organic semiconductor thin films to be used in optoelectronic devices. Atomic‐force microscopy is a vital tool to quantitatively analyze the evolving crystalline nanostructures and their spontaneous ordering. Here, para‐sexiphenyl – a semiconducting light emitting oligomer – has been grown epitaxially by different high vacuum and ultra high vacuum methods onto crystalline substrates like mica(001), TiO2(110), or Al(111). Depending on the actual growth parameters, characteristically shaped crystallites composed of lying molecules or terraced mounds of upright standing molecules are formed. With ongoing deposition, quasi 1D arrays of crystallites can evolve due to a rearrangement process of the earlier formed crystallites. For highly anisotropic surfaces, like mica(001) and TiO2(110), these para‐sexiphenyl structures are correlated to the surface geometry of the substrate. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)