Dresden 2009 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
DS: Fachverband Dünne Schichten
DS 26: Poster II
DS 26.17: Poster
Wednesday, March 25, 2009, 09:30–12:30, P5
Gold work function reduction by 2.2 eV with an air-stable molecular donor layer — •Benjamin Bröker1, Ralf-Peter Blum1, Johannes Frisch1, Antje Vollmer2, Oliver T. Hofmann3, Ralph Rieger4, Klaus Müllen4, Jürgen P. Rabe1, Egbert Zojer3, and Norbert Koch1 — 1Institut für Physik, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12389 Berlin, Germany — 2Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung mbH, D-12489 Berlin, Germany — 3Institut of Solid State Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria — 4Max Planck Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany
Ultraviolet photoelectron spectroscopy was used to investigate neutral methyl viologen (1,1'-dimethyl-1H,1'H-[4,4']bipyridinylidene, MV0) deposited on Au(111) surfaces. As a result of molecule-to-metal electron transfer, the work function of Au(111) was decreased from 5.5 eV to 3.3 eV. The energy levels of electron transport layers deposited on top of modified Au surfaces were shifted to higher binding energy compared to layers on pristine Au, and the electron injection barrier was reduced by 0.8 eV for tris(8-hydroxyquinoline)aluminum (Alq3) and by 0.7 eV for C60. The air-stable donor MV0 can thus be used to facilitate electron injection into organic semiconductors even from high work function metals.
This work is financially supported by European Community project "IControl" (EC-STREP-033197).