Berlin 2005 – wissenschaftliches Programm
SYOO 6.24: Poster
Montag, 7. März 2005, 18:00–20:00, Poster TU A
Scanning Kelvin Probe Microscopy Investigations of Au-P3HT-Au Structures for Organic Field Effect Transistors — •Andrii Goriachko, Klaus Müller, Ioanna Paloumpa, and Dieter Schmeißer — Lehrstuhl Angewandte Physik / Sensorik, BTU Cottbus, Konrad-Wachsmann-Allee 1, 03046 Cottbus, Germany
We report on the scanning Kelvin probe microscopy (SKPM) investigation of the source-channel-drain structures of organic field effect transistor (OFET). A poly-3-hexyl-thiophen (P3HT) organic semiconductor film, spin-coated on a glass-substrate and 65 nm thick, is used as a 2 mkm channel between Au source (drain) electrodes. Depending on the preparation conditions, the P3HT film consists of either amorphous nm-seized molecular clsuters or mkm-long chains. The SKPM allows mapping of electric potential along with the surface topography on the DC-biased structures (8V applied between source and drain). It reveals a linear potential fall in the channel region as well as the abscence of potential jumps (contact resistance) in the electrode/channel regions. This is a direct indication of the top-gate OFET type advantage, which the given structure is suited for. Due to the high spatial resolution of the UHV-based SKPM, doping inhomogenities of the p-type P3HT semiconductor as well as the space charge region on the electron injecting electrode are observed. In addition we present SKPM investigations of the structure with source and drain electrodes but without a semiconductor, showing electric field configuration for the given electrodes geometry.