Subnanosecond geminate charge recombination in polymer-polymer photovoltaic devices.
We present direct spectroscopic evidence for substantial subnanosecond charge recombination in polymer-polymer blend photovoltaic devices. Early dynamics are dominated by exciton-charge interactions associated with high initial excitation densities. Independent of density, 30% of charges subsequently recombine geminately within just 2 nanoseconds, in contrast with fullerene blends. The remainder recombines with a half-life of approximately 200 ns. The morphological invariance of subnanosecond recombination suggests that its origin is inherent in the molecular structure at the polymer-polymer interface.
Hodgkiss
Justin M
JM
Cavendish Laboratory, Department of Physics, University of Cambridge, CB3 0HE, United Kingdom. Justin.Hodgkiss@vuw.ac.nz
Campbell
Andrew R
AR
Marsh
R Alex
RA
Rao
Akshay
A
Albert-Seifried
Sebastian
S
Friend
Richard H
RH