Berlin 2018 – wissenschaftliches Programm
O 81: Poster Focus Session: Molecular Nanostructures on Surfaces - New Concepts towards Complex Architectures
O 81.18: Poster
Mittwoch, 14. März 2018, 18:15–20:30, Poster A
DHTAP thin layers deposited on Cu(110) and Cu(110)-(2×1)O surfaces — •Andrea Navarro-Quezada1,2, Michael Györök2, Thorsten Wagner2, Anthony Thomas3, Thomas Leoni3, Alain Ranguis3, Conrad Becker3, and Peter Zeppenfeld2 — 1Solid State and Semiconductor Physics, JKU Linz, Austria — 2Experimental Physics, JKU Linz, Austria — 3CINAM, Marseille, France
Dihydrotetraazapentacene (DHTAP) is a derivate of pentacene, which due to its two H-donor (N-H) and the two H-acceptor (N=C) sites, is expected to form well-ordered molecular structures on surfaces. Here, we study the morphology and the evolution of the optical properties during the deposition of DHTAP thin layers on Cu(110) and Cu(110)-(2×1)O surfaces using polarization-dependent differential reflectance spectroscopy (pol-DRS) in combination with photoelectron emission microscopy (PEEM). We compare our results to those obtained by in situ reflectance differential spectroscopy (RDS) in a second experiment. Within the first monolayer, DHTAP absorbes in a flat-lying geometry on both surfaces. However, the orientation of the long molecular axis of the molecules in the first monolayer is aligned along the [1-10]-direction on the Cu(110) surface, while it is parallel to the -direction on Cu(110)-(2x1)O. We find that, depending on the growth temperature, the DHTAP molecules on top of the first monolayer deposited on Cu(110) change their preferential alignment.
 A. Navarro-Quezada et al., Rev. Sci. Instr. 86, 113108 (2015)