Dynamics of charge transfer states in organic semiconductor devices: A combined experimental and simulation-based approach

• Applicant: Professor Dr. Wolfgang Brütting
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 432420985

The aim of the proposed project is to study the dynamics of charge transfer states (also denoted as CT excitons) in organic donor-acceptor systems and, specifically, the interplay between different excitonic species as well as between CT excitons and charge carriers, both in the bulk of individual layers (intra-molecular) and at interfaces of multilayer organic semiconductor devices (inter-molecular). This requires the preparation of clean model systems to isolate the underlying processes by dedicated experiments on the one hand; on the other hand the model needs to be extended to capture the enhanced complexity of these systems. The dynamics of CT states can be studied in both OLED and solar cell configurations. In fact, due to basic thermodynamics and reciprocity many of the findings from OLEDs may be transferred to solar cells and vice versa. Therefore we aim to establish dedicated experiments that allow for example to measure the open-circuit voltage of OLEDs or the luminance of solar cells. With regards to simulation we aim for a comprehensive and universal model covering all processes and which can be employed for both OLEDs and solar cells.

• DFG Programme: Research Grants
• International Connection: Switzerland
• Cooperation Partner: Professor Dr. Beat Ruhstaller