Berlin 2012 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 16: Scanning probe methods II
O 16.5: Talk
Monday, March 26, 2012, 17:00–17:15, MA 043
Molecular ordering and local work function of pentacene on ioniccrystalline surfaces — •Julia Neff1, Jan Götzen1,2, Peter Milde3, and Regina Hoffmann-Vogel1 — 1Karlsruher Institut für Technologie, Physikalisches Institut, 76131 Karlsruhe, Germany — 2Mechanical Engineering and Materials Science, Yale University, CT 06511, USA — 3Institut für Angewandte Photophysik, Technische Universität Dresden, 01069 Dresden, Germany
The electronic properties of molecular thin films are closely related to their structural order. Therefore a precise control of the molecular packing and the crystalline orientation of semiconducting organic molecules like pentacene is of vital interest for the optimization of organic electronic devices. The growth of pentacene on KCl(001) and KBr(001) at submonolayer coverage was studied by dynamic scanning force microscopy. Pentacene was found to arrange in islands with an upright configuration on these bulk insulators. Molecularly resolved images of the islands show two different types of patterns that appear to switch repeatedly. In both patterns defects, such as a molecular vacancy and domain boundaries, were observed. Insight into the electronic structure is gained by Kelvin probe force microscopy. The measured charge densities show differences of about 1V between bare substrate regions and pentacene islands.