Ultrafast relaxation dynamics in a polymer: fullerene blend for organic photovoltaics probed by two-dimensional electronic spectroscopyAntonietta De Sio, Franco V.d.A. Camargo, Katrin Winte, Ephraim Sommer, Federico Branchi, Giulio Cerullo and Christoph LienauEur. Phys. J. B, 91 10 (2018) 236DOI: https://doi.org/10.1140/epjb/e2018-90216-4