Regensburg 2004 – wissenschaftliches Programm
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SYOH: Organic and Hybrid Systems for Future Electronics
SYOH 5: Poster
SYOH 5.14: Poster
Donnerstag, 11. März 2004, 18:00–21:00, B
The Growth of Pentacene on Gold — •F.-J. Meyer zu Heringdorf1,2, M.C. Reuter1, and R.M. Tromp1 — 1IBM T.J. Watson Research Center, Yorktown Heights, USA — 2present address:Inst. für Laser- und Plasmaphysik, Universität Duisburg-Essen (Campus Essen)
We used Low Energy Electron Microscopy and Atomic Force Microscopy to compare the growth of pentacene on Si(111) with the growth of pentacene on Au. In the LEEM Au films are prepared on Si(111) at elevated temperatures and their formation is monitored using quasi-simultaneous imaging at different dark field conditions. At low coverages, Au forms a (5×2) reconstruction on the Si(111) substrate, and pentacene is observed to grow in the thin film phase, similar to growth on clean silicon. At coverages beyond 3/4 ML of Au, however, a (√3×√3) reconstruction is formed that causes the orientation of the pentacene film to rotate by almost 90∘. The same result is found for pentacene on thick polycrystalline Au films. The adsorption of organic self-assembled monolayers (SAMs) prior to deposition of pentacene has been reported to improve the electrical contact between Au and pentacene. Here we show that thiol based SAMs on Au can restore the growth direction of pentacene to a crystal orientation as seen on Si. This demonstrates that carefully chosen organic substrate termination layers are likely to play a key role in the development of organic thin film semiconductor technology.