Role of Polymer Fractionation in Energetic Losses and Charge Carrier Lifetimes of Polymer: Fullerene Solar Cells - Baran, D; Vezie, MS; Gasparini, N; Deledalle, F; Yao, J; Schroeder, BC; Bronstein, H; Ameri, T; Kirchartz, T; McCulloch, I; Nelson, J; Brabec, CJ (JOURNAL OF PHYSICAL CHEMISTRY C, 2015)