Understanding energetics of organic-organic interfaces and mixtures
Event details
| Date | 17.11.2016 |
| Hour | 16:30 › 17:30 |
| Speaker |
Dr. Denis Andrienko Max Planck Institute for Polymer Research |
| Location | |
| Category | Conferences - Seminars |
We will discuss the role of mesoscale order, electrostatic effects, defects, and roughness for charge splitting and detrapping at donor-acceptor interfaces. We will show how inclusion of mesoscale order resolves the controversy between experimental and theoretical results for the energy-level profile and alignment in a variety of photovoltaic systems, with direct experimental validation. We predict open-circuit voltages of planar heterojunction solar cells in excellent agreement with experimental data, based only on crystal structures and interfacial orientation. We show how long-range molecular order and interfacial mixing generate homogeneous electrostatic forces that can drive charge separation and prevent minority carrier trapping across a donor-acceptor interphase. Comparing a variety of small-molecule donor-fullerene combinations, we illustrate how tuning of molecular orientation and interfacial mixing leads to a trade-off between photovoltaic gap and charge-splitting and detrapping forces, with consequences for the design of efficient photovoltaic devices.
[1] C. Poelking, M. Tietze, C. Elschner, S. Olthof, D. Hertel, B. Baumeier, F. Wuerthner, K. Meerholz, K. Leo, D. Andrienko, Nature Materials, 14, 434-439, 2015 [2] C. Poelking, D. Andrienko, J. Am. Chem. Soc., 137, 6320-6326, 2015 [3] M. Schwarze, W. Tress, B. Beyer, F. Gao, R. Scholz, C. Poelking, K. Ortstein, A. A. Guenther, D. Kasemann, D. Andrienko, K. Leo, Science, 2016 [4] C. Poelking, D. Andrienko, J. Chem. Theory Comput., 2016, 12, 4523
Practical information
- Expert
- Free
- This event is internal
Organizer
- Prof. Ulrich Lorenz
Contact
- Prof. Ulrich Lorenz