Picosecond transient photoconductivity in functionalized pentacene molecular crystals probed by terahertz pulse spectroscopy.
We have measured transient photoconductivity in functionalized pentacene molecular crystals using ultrafast optical pump-terahertz probe techniques. The single crystal samples were excited using 800 nm, 100 fs pulses, and the change in transmission of time-delayed, subpicosecond terahertz pulses was used to probe the photoconducting state over a temperature range from 10 to 300 K. A subpicosecond rise in photoconductivity is observed, suggesting that mobile carriers are a primary photoexcitation. At times longer than 4 ps, a power-law decay is observed consistent with dispersive transport.
Hegmann
F A
FA
Department of Physics, University of Alberta, Edmonton, Canada T6G 2J1. hegmann@phys.ualberta.ca
Tykwinski
R R
RR
Lui
K P H
KP
Bullock
J E
JE
Anthony
J E
JE