TY - JOUR A1 - Pollinger, Florian A1 - Schmitt, Stefan A1 - Sander, Dirk A1 - Tian, Zhen A1 - Kirschner, Jürgen A1 - Vrdoljak, Pavo A1 - Stadler, Christoph A1 - Maier, Florian A1 - Marchetto, Helder A1 - Schmidt, Thomas A1 - Schöll, Achim A1 - Umbach, Eberhard T1 - Nanoscale patterning, macroscopic reconstruction, and enhanced surface stress by organic adsorption on vicinal surfaces JF - New Journal of Physics N2 - Self-organization is a promising method within the framework of bottom-up architectures to generate nanostructures in an efficient way. The present work demonstrates that self- organization on the length scale of a few to several tens of nanometers can be achieved by a proper combination of a large (organic) molecule and a vicinal metal surface if the local bonding of the molecule on steps is significantly stronger than that on low-index surfaces. In this case thermal annealing may lead to large mass transport of the subjacent substrate atoms such that nanometer-wide and micrometer-long molecular stripes or other patterns are being formed on high-index planes. The formation of these patterns can be controlled by the initial surface orientation and adsorbate coverage. The patterns arrange self-organized in regular arrays by repulsive mechanical interactions over long distances accompanied by a significant enhancement of surface stress. We demonstrate this effect using the planar organic molecule PTCDA as adsorbate and Ag(10 8 7) and Ag(775)surfaces as substrate. The patterns are directly observed by STM, the formation of vicinal surfaces is monitored by highresolution electron diffraction, the microscopic surface morphology changes are followed by spectromicroscopy, and the macroscopic changes of surface stress are measured by a cantilever bending method. The in situ combination of these complementary techniques provides compelling evidence for elastic interaction and a significant stress contribution to long-range order and nanopattern formation. KW - physics KW - patterning KW - reconstruction KW - surface stress KW - STM KW - SPA-LEED KW - vicinal surfaces KW - adsoption Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171947 VL - 19 ER - TY - JOUR A1 - Lüftner, Daniel A1 - Milko, Matus A1 - Huppmann, Sophia A1 - Scholz, Markus A1 - Ngyuen, Nam A1 - Wießner, Michael A1 - Schöll, Achim A1 - Reinert, Friedrich A1 - Puschnig, Peter T1 - CuPc/Au(1 1 0): Determination of the azimuthal alignment by a combination of angle-resolved photoemission and density functional theory JF - Journal of Electron Spectroscopy and Related Phenomena N2 - Here we report on a combined experimental and theoretical study on the structural and electronic properties of a monolayer of Copper-Phthalocyanine (CuPc) on the Au(1 1 0) surface. Low-energy electron diffraction reveals a commensurate overlayer unit cell containing one adsorbate species. The azimuthal alignment of the CuPc molecule is revealed by comparing experimental constant binding energy (kxky)-maps using angle-resolved photoelectron spectroscopy with theoretical momentum maps of the free molecule's highest occupied molecular orbital (HOMO). This structural information is confirmed by total energy calculations within the framework of van-der-Waals corrected density functional theory. The electronic structure is further analyzed by computing the molecule-projected density of states, using both a semi-local and a hybrid exchange-correlation functional. In agreement with experiment, the HOMO is located about 1.2 eV below the Fermi-level, while there is no significant charge transfer into the molecule and the CuPc LUMO remains unoccupied on the Au(1 1 0) surface. KW - density functional theory KW - angle-resolved photoemission spectroscopy KW - organic molecule KW - organic–metal interface Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120986 SN - 0368-2048 VL - 195 ER -