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 . 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  and mesoscopically amorphous systems with high accuracy .
 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
 C. Poelking, D. Andrienko, J. Am. Chem. Soc., 137, 6320, 2015
 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
 C. Poelking, D. Andrienko J. Chem. Theory Comput., 12, 4516, 2016