Regensburg 2004 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

SYOH: Organic and Hybrid Systems for Future Electronics

SYOH 5: Poster

SYOH 5.21: Poster

Thursday, March 11, 2004, 18:00–21:00, B

Doping and Diffusion Properties of Na in PTCDA Thin Films — •Jens Wüsten, Steffen Berger, Stefan Lach, and Christiane Ziegler — University of Kaiserslautern, Department of Physics, Erwin-Schrödinger-Straße 56, D-67663 Kaiserslautern

In order to investigate the electronic and vibronic properties of n-doped PTCDA (perylene-3,4,9,10-tetracarboxylic-dianhydride), thin films were grown under UHV conditions. The n-doping was performed by subsequently evaporating sodium (Na) from a dispenser source, followed by one or several annealing steps to reach a homogeneous distribution of the dopant throughout the layer.

Experimental results from electronic (XPS/UPS/IPE), conductivity, Seebeck, vibration (FT-IR), angle resolved XPS and SIMS measurements of Na doped PTCDA before and after annealing will be presented. The changes in the elctronic structure and the electrical properties show that doping is already established after Na evaporation. However, the results suggest that the model of an initially built doped surface layer and a subsequent diffusion of Na into the PTCDA bulk during the annealing step is incorrect. In fact evidences could be found, that the deposited dopant initially establishes a homogeneous distribution in the PTCDA layer and is partially removed during the annealing step.