Proceedings Article | 18 September 2018
KEYWORDS: Interfaces, Photovoltaics, Ionization, Solar energy, Crystals, Americium, System on a chip
We 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 [1,2]. We explain how this order and interfacial roughness generate electrostatic forces that drive charge
separation and prevent carrier trapping across a donor-acceptor interface [2]. Comparing several 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. By accounting for long-range mesoscale fields, we obtain the ionization energies in both crystalline [3] and mesoscopically amorphous systems with high accuracy [4].
[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, 2015
[2] C. Poelking, D. Andrienko, J. Am. Chem. Soc., 137, 6320, 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, 352, 1446, 2016
[4] C. Poelking, D. Andrienko J. Chem. Theory Comput., 12, 4516, 2016
