Charge photogeneration in donor/acceptor organic solar cells - Shoaee,S; Clarke,TM; Eng,MP; Huang,C; Barlow,S; Espildora,E; Luis,Delgado J; Campo,B; Marder,SR; Heeney,M; McCulloch,I; Martin,N; et al. (JOURNAL OF PHOTONICS FOR ENERGY, 2012)