title: Direct imaging of free carrier and trap carrier motion in silicon nanowires by spatially-separated femtosecond pump-probe microscopy.
abstract: We have developed a pump-probe microscope capable of exciting a single semiconductor nanostructure in one location and probing it in another with both high spatial and temporal resolution. Experiments performed on Si nanowires enable a direct visualization of the charge cloud produced by photoexcitation at a localized spot as it spreads along the nanowire axis. The time-resolved images show clear evidence of rapid diffusional spreading and recombination of the free carriers, which is consistent with ambipolar diffusion and a surface recombination velocity of ∼10(4) cm/s. The free carrier dynamics are followed by trap carrier migration on slower time scales.
authors: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
authors: Michelle M
authors: MM
authors: Gabriel
authors: Justin R
authors: JR
authors: Kirschbrown
authors: Joseph D
authors: JD
authors: Christesen
authors: Christopher W
authors: CW
authors: Pinion
authors: David F
authors: DF
authors: Zigler
authors: Erik M
authors: EM
authors: Grumstrup
authors: Brian P
authors: BP
authors: Mehl
authors: Emma E M
authors: EE
authors: Cating
authors: James F
authors: JF
authors: Cahoon
authors: John M
authors: JM
authors: Papanikolas