Dresden 2003 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

CPP: Chemische Physik und Polymerphysik

CPP 20: POSTER A

CPP 20.55: Poster

Montag, 24. März 2003, 19:00–21:00, ZEU/250

Chirality transfer from single molecules into self-assembled monolayers — •Manfred Parschau, Roman Fasel, and Karl-Heinz Ernst — Swiss Federal Laboratories for Materials Research, Ueberlandstrasse 129, CH-8600 Duebendorf

Highly ordered chiral materials are the key to devices for circularly polarized electroluminescence (CPEL). Furthermore, the outstanding nonlinear optical properties of chiral films attracted some interest recently. On the other hand, the interface properties between the organic film and the electrode are crucial for the efficiency of organic light-emitting devices (OLEDs). In order to generate highly ordered chiral films, we perform a layer by layer deposition of chiral molecules. As a first step, the two-dimensional self-assembly of heptahelicene ([7]H), a helically shaped polyaromatic hydrocarbon (C30H18), on the copper(111) surface was investigated. The molecules were deposited via molecular beam technique and studied with variable-temperature scanning tunneling microscopy (VTSTM) at temperatures between 60 and 400 K. The adsorption of enantiopure heptahelicene on Cu(111) leads to well-ordered superstructures. Depending on surface coverage, the chirality of the molecules is transferred either into handed nanoclusters consisting of six molecules or into No-dqlong-range-twistedNo-dq chiral superstructures.