Kerstin Keller

Organic Donor-acceptor Thin Film Systems: Towards Optimized Growth Conditions Kerstin Keller

In this work the preparation of organic donor- acceptor thin films via physical vapor deposition is studied in theory and experiment. A chamber for organic molecular beam deposition was designed and integrated into an existing deposition system. Additionally, a load-lock, a chamber to prepare metallic contacts via stencil mask technique and a sputtering chamber were built. For the sublimation of organic compounds several effusion cells were constructed and the evaporation characteristics were compared to a simulation. The developed simulation program calculates the respective evaporation characteristics. It contains evaporation of particles, migration, and collisions in the gas phase. For the preparation and characterization of organic thin films it was focused on the charge transfer salt (BEDT-TTF)(TCNQ). Thin films were prepared by co-evaporation and studied with optical microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy (EDX). The formation of the monoclinic phase of (BEDT-TTF)(TCNQ) could be shown. As a last part complete devices (tunnel structures) were prepared and measured in a He4 cryostat.