title: Self-Assembly of Tetraphenyldibenzoperiflanthene (DBP) Films on Ag(111) in the Monolayer Regime.
abstract: Tetraphenyldibenzoperiflanthene (DBP) is a promising candidate as a component of highly efficient organic photovoltaic cells and organic light-emitting diodes. The structural properties of thin films of this particular lander-type molecule on Ag(111) were investigated by complementary techniques. Highly ordered structures were obtained, and their mutual alignment was characterized by means of low-energy electron diffraction (LEED). Scanning tunneling microscopy (STM) images reveal two slightly different arrangements within the first monolayer (ML), both describable as specific herringbone patterns with two molecules per unit cell whose dibenzoperiflanthene framework is parallel to the surface. In contrast, single DBP molecules in the second ML were imaged with much higher intramolecular resolution, resembling the shape of the frontier orbitals in the gas phase as calculated by means of density functional theory (DFT). Further deposition leads to the growth of highly ordered bilayer islands on top of the first ML with identical unit cell dimensions and orientation but slightly inclined molecules. This suggests that the first ML acts as a template for the epitaxial growth of further layers. Simultaneously, a significant number of second-layer molecules mainly located at step edges or scattered over narrow terraces do not form highly ordered aggregates.
authors: Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 5, 07743 Jena, Germany.
authors: Tino
authors: T
authors: Kirchhuebel
authors: Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 5, 07743 Jena, Germany.
authors: Marco
authors: M
authors: Gruenewald
authors: Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 5, 07743 Jena, Germany.
authors: Falko
authors: F
authors: Sojka
authors: Institute for Molecular Science , Myodaiji, Okazaki 444-8585, Japan.|SOKENDAI, The Graduate University for Advanced Studies , Okazaki 444-8585, Japan.|Graduate School of Advanced Integration Science, Chiba University , Chiba 263-8522, Japan.
authors: Satoshi
authors: S
authors: Kera
authors: Institute for Molecular Science , Myodaiji, Okazaki 444-8585, Japan.
authors: Fabio
authors: F
authors: Bussolotti
authors: Institute for Molecular Science , Myodaiji, Okazaki 444-8585, Japan.|SOKENDAI, The Graduate University for Advanced Studies , Okazaki 444-8585, Japan.
authors: Takahiro
authors: T
authors: Ueba
authors: Graduate School of Advanced Integration Science, Chiba University , Chiba 263-8522, Japan.
authors: Nobuo
authors: N
authors: Ueno
authors: Laboratory Astrophysics Group of the Max Planck Institute for Astronomy, Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 3, 07743 Jena, Germany.
authors: Gaël
authors: G
authors: Rouillé
authors: Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 5, 07743 Jena, Germany.
authors: Roman
authors: R
authors: Forker
authors: Institute of Solid State Physics, Friedrich Schiller University Jena , Helmholtzweg 5, 07743 Jena, Germany.|Department of Chemistry, Graduate School of Science and Institute for Academic Initiatives, Osaka University , 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
authors: Torsten
authors: T
authors: Fritz