Abstract
The carrier mobility (µ) and lifetime (τ) of polymer solar cells based on the active layer with various compositions of regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have been investigated through photoinduced charge carrier extraction by linearly increasing voltage measurement. Increase in the PCBM content resulted in the increase in the mobility up to one order of magnitude and the highest performance was attained at the composition of P3HT:PCBM (3:2), which corresponds to the bending point of mobility and lifetime. Furthermore, the mobility-lifetime product µτ was almost constant with various weight ratios of P3HT and PCBM. This result implies that the composition does not affect the charge correction efficiency before recombination. A semiconducting thin-film optics simulator was applied for prediction of the photovoltaic performance. Theoretical and experimental cell performance results were in good agreement with each other.