Annealed Treatment Effect in Poly(3-hexylthiophene):Methanofullerene Solar Cells

Polymer photovoltaic devices based on poly(3-hexylthiophene) (P3HT) : 6,6-phenyl-C₆₁-butyricacid methyl ester (PCBM) 1:1 weight-ratio blend are reported. The effects of various annealing treatments on the device performance are investigated. Thermal annealing shows significant improvement of the device performances. For devices at 130°C annealing, maximum power conversion efficiency (PCE) of 3.3% and fill factor up to 60.3% is achieved under air mass 1.5, 100mW/cm² illumination. We discuss the effect of thermal annealing by the results of ultraviolet-visible absorption spectroscopy (UV-vis), dark current-voltage curve, atomic force microscopy (AFM).