Na. Anderson et al., Ultrafast and long-lived photoinduced charge separation in MEH-PPV/nanoporous semiconductor thin film composites, CHEM P LETT, 347(4-6), 2001, pp. 304-310
Photoinduced charge separation and recombination dynamics were investigated
in composite materials of conjugated polymer deposited on nanocrystalline
metal oxide thin film. Using femtosecond IR transient absorption spectrosco
py, the electron transfer from the excited state of poly[2-methoxy-5-(2-eth
yl-hexyloxy)-(phenylene vinylene)] (MEH-PPV) to SnO2 and TiO2 nanoporous th
in films is shown to occur with timescales of 800 and < 100 fs, respectivel
y. Negligible carrier recombination is observed for MEH-PPV/SnO2 within 1 n
s. Microsecond charge recombination dynamics were measured using step-scan
FTIR. Long-lived charge separation is observed in both systems, persisting
for microseconds to seconds. (C) 2001 Elsevier Science B.V. All rights rese
rved.