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DS: Fachverband Dünne Schichten
DS 62: Organic Thin Films I
DS 62.1: Vortrag
Freitag, 18. März 2011, 10:15–10:30, GER 38
AFM based density-of-states measurements on organic thin films — •Markus Kratzer1, Igor Beinik1, Astrid Wachauer1, Mujeeb Ullah2, Helmut Sitter2, and Christian Teichert1 — 1Institute of Physics, University of Leoben, Franz Josef Straße 18, A8700 Leoben, Austria — 2Institute of Semiconductor and Solid State Physics, Johannes Kepler University of Linz, A4040, Austria
The performance of electrical devices based on organic materials crucially depends on the charge transport properties. For the understanding of the charge carrier transport in organic molecular films knowledge on the density of states (DOS) is of fundamental importance. In this study, we present DOS measurements based on Kelvin Probe Force Microscopy (KPFM) [1, 2] of the organic n-type semiconductor C60 and the p-type semiconductor Para-hexaphenyl (6P). For the n-type conductor, the electron DOS and for the p-type conductor the hole density of states can be derived from the KPFM data. For this purpose, organic thin film transistor structures were prepared utilizing Hot Wall Epitaxy. The substrate temperature during deposition was varied between 273 K and 423 K resulting in films of different degrees of crystallinity. KPFM was then applied in inert atmosphere to prevent degradation of the films by oxidation. The results are discussed.
Supported by Austrian Science Fund (FWF) NFN projects S9706-N20, S9707-N20 and P19636.
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