Effects of photo-oxidation on the performance of poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene]:[6,6]-phenyl C61-butyric acid methyl ester solar cells - Pacios, R; Chatten, AJ; Kawano, K; Durrant, JR; Bradley, DDC; Nelson, J (ADVANCED FUNCTIONAL MATERIALS, 2006)