title: Subnanosecond charge photogeneration and recombination in polyfluorene copolymer-fullerene solar cell: effects of electric field.
abstract: Influence of electric field on the subnanosecond charge photogeneration dynamics in the polymer solar cell based on polyfluorene copolymer BisDMO-PFDTBT blended with PC(61)BM was examined with transient absorption spectroscopy. The charge dynamics showed no difference under short- or open-circuit conditions and under a forward bias of 0.79 V (1.6 × 10(5) V/cm), implying negligible field effects on the subnanosecond dynamics of charge photogeneration/recombination. However, under the reverse biases of -2 V (4.0 × 10(5) V/cm) and -5 V (1.0 × 10(6) V/cm), significant enhancement of charge photogeneration and apparent suppression of polaron pair recombination were observed, which agrees with the field-assisted enhancement of external quantum efficiency of the solar cell devices.
authors.affiliation: Department of Physics, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Ye
authors.initials: Y
authors.lastname: Huang
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Xing
authors.forename: Yan
authors.initials: Y
authors.lastname: Jing
authors.forename: Long
authors.initials: L
authors.lastname: Ye
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Fu
authors.forename: Xi-Cheng
authors.initials: XC
authors.lastname: Ai
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Hou
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Zhang