Broadband exciton dynamics in P3HT:PCBM blended film was observed by the femtosecond time-resolved photoluminescence sum-frequency technique. Onsager–Braun theory is applied to analyze the distribution of charge transfer radius at different energy levels. In our evaluation, the optimal diameter of P3HT fiber is about 14.3 nm for achieving the best exciton dissociation in P3HT:PCBM blended films. This technique can be readily used in the optimization of high-efficiency organic photovoltaics.
© 2013 Optical Society of America
Original Manuscript: October 24, 2013
Revised Manuscript: November 11, 2013
Manuscript Accepted: November 12, 2013
Published: December 9, 2013
Sheng Hsiung Chang, Chien-Hung Chiang, Hsin-Ming Cheng, Chao-Yi Tai, and Chun-Guey Wu, "Broadband charge transfer dynamics in P3HT:PCBM blended film," Opt. Lett. 38, 5342-5345 (2013)