SMuK 2023 – scientific programme
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AKE: Arbeitskreis Energie
AKE 1: Konzepte und Technologien
AKE 1.2: Talk
Monday, March 20, 2023, 11:30–11:45, GER/038
Numerical Simulation of the coating process for organic photovoltaics — •Fabian Gumpert1, Annika Janßen1,2, Andreas Distler2, Christoph J. Brabec2, Hans-Joachim Egelhaaf2, and Jan Lohbreier1 — 1Nuremberg Institute of Technology, Nuremberg, Germany — 2Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
In various industrial applications, the doctor blading process is a well-established technique to coat thin films. In the context of organic photovoltaics, functional layers like electrodes, active materials, and interfacial layers are printed using this technique. For the performance and lifetime of the final photovoltaic devices, the thickness precision and uniformity of the individual layers is crucial.
Computational Fluid Dynamics (CFD) simulations and experiments are used to study the effect of various parameters on the film formation during doctor blading. For example, a numerically simulated correlation between coating speed and wet film thickness is established and found to match the experimental findings.
With the help of these CFD simulations, process parameters and resulting film thicknesses can be predicted based on simple fluid characteristics such as viscosity and surface tension. Furthermore, the observed decrease in the wet film thickness over printed distance, which relates to the decreasing volume in the meniscus, can be compensated by a calculated acceleration of the applicator during the coating process to drastically increase the distance range of homogeneous coating by doctor blading.