Subpicosecond photoinduced electron transfer from a conjugated polymer to SnO2 semiconductor nanocrystals

Photoinduced electron transfer from the conjugated polymer poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylenevinylene] (MEH-PPV) to a SnO2 nanoporous thin film was studied using ultrafast IR spectroscopy. The absorption signals observed using this technique correspond to electron transfer, minimizing signal contamination from other processes. The electron transfer from polymer to nanocrystal was found to occur on an 800 fs timescale. The fast and efficient charge separation is attributed to the large interface area and favorable energetics for transfer. Charge separation is long-lived, persisting for microseconds. (C) 2002 Elsevier Science B.V. All rights reserved.