title: Ultrafast terahertz photoconductivity of bulk heterojunction materials reveals high carrier mobility up to nanosecond time scale.
abstract: The few-picosecond (ps) decay of terahertz (THz) photoconductivity typically observed for conjugated polymer:fullerene blends (at excitation fluencies ~10(15) photons/cm(2) per pulse) is shown to be a result of charge pair annihilation for two polymer:PCBM blends. At a factor of 100 lower excitation density, the THz decay is in the hundreds of ps time scale, implying that very high carrier mobility (~0.1 cm(2) V(-1) s(-1)) prevails for long time after charge formation, of importance for free charge formation in organic solar cells.
authors: Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden.
authors: Carlito S
authors: CS
authors: Ponseca
authors: Arkady
authors: A
authors: Yartsev
authors: Ergang
authors: E
authors: Wang
authors: Mats R
authors: MR
authors: Andersson
authors: Dimali
authors: D
authors: Vithanage
authors: Villy
authors: V
authors: Sundström