Berlin 2015 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

DS: Fachverband Dünne Schichten

DS 39: Poster Session II

DS 39.22: Poster

Thursday, March 19, 2015, 16:00–18:30, Poster F

Epitaxial Growth and Photoluminescence of α-Sexithiophene on KCl- and Si/SiO2-Substrates — •Frieder Lennart Müntze^1,2, Hisao Yanagi², and Derck Schlettwein¹ — ¹Institute of Applied Physics, Justus-Liebig-University Gießen, D-35390 Giessen — ²Graduate School of Materials Science, Nara Institute of Science and Technology, Nara 630-0192, Japan

α-Sexithiophene (α−6T) is a well-known organic semiconductor with possible applications in organic electronics. Different crystalline phases of α−6T have been established. Either nanofibers or 3D islands can be formed. This has an influence on the photoluminescence(PL)-properties of the materials. In this work, three differently coloured domains of α−6T were obtained in sublimation studies. These samples were analysed with UV-vis, PL-spectroscopy and XRD to determine the respective crystal phase. Thins films were studied which proved to be of the LT-structure established in the literature for films grown on KCl (001) or onto Si/SiO₂ substrates for temperatures up to 150 ^∘C. On the KCl, we found nanofibers while on the Si/SiO₂ substrates, islands were formed. When excited by UV the islands emitted in the green part of the spectrum while the needles on KCl emitted orange. For films grown on KCl at 180 ^∘C, however, needles were formed that emitted in the green part of the spectrum. Based on these findings, based on the polarization dependence of the emission intensity and based on the orientation of the needles relative to the substrate the orientation of α−6T relative to the different substrate surfaces is discussed.