Dependence of Charge Separation Efficiency on Film Microstructure in Poly(3-hexylthiophene-2,5-diyl): [6,6]-Phenyl-C61 Butyric Acid Methyl Ester Blend Films - Keivanidis,PE; Clarke,TM; Lilliu,S; Agostinelli,T; Macdonald,JE; Durrant,JR; Bradley,DDC; Nelson,J (JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 2010)