Evaluation of the characteristics of the organic thin film solar cell fabricated by poly[4,8-bis(2-ethylhexyloxy)-benzo[1,2-b:4,5-′b] dithiophene-2,6-diyl-alt-(4-octanoyl-5-fluoro-thieno[3,4-b] thiophene-2-carboxylate)-2,6-diyl]/[6,6]-phenyl-C71-butyric acid methyl ester

Solar energy is the most abundant and reliable source of energy and we have to provide for the multi-terawatt challenge we are facing. In recent years organic photovoltaic's have become one of the most interesting research areas due to their potential towards a cheap and broad applicability. We report the optical and electrical properties of PBDTTT-CF:PC71BM bulk hetero-junction (BHJ) solar cell. The devices were prepared by spin coating technique with the device structure of Glass/ITO/PEDOT:PSS/Active layer/Al. The ratio of polymer donor and fullerene acceptor varied between 1:1 to 1:4. Optical absorption spectroscopy measurements of the films indicated absorption peaks in the range from 500-800 nm which were attributed to PBDTTT-CF. The surface morphology of the active layers deposited was examined using Atomic Force Microscopy. The current density (J)-voltage (V) characteristics of the PBDTTT-CF:PC71BM bulk hetero-junction solar cells were studied. The devices fabricated using the selective active layer show overall power conversion efficiency of 3%.