Ultrafast electron transfer between conjugated polymer and antimony-doped tin oxide (ATO) nanoparticles

Nanocomposites of conjugated polymers and wide band gap metal oxide semiconductors have received intense interests in recent years because of their potential application in solar cells. Photoinduced charge separation and recombination in conjugated poly[2-methoxy-5-(2-ethyl-hexyloxy)-(phenylene vinylene)] (MEH-PPV) sensitized Sb:SnO2 (ATO) nanocrystalline thin films were investigated by ultrafast transient IR spectroscopy. For ATO films with 0%, 1%, 3%, and 5% Sb dopants, the rates of electron injection from MEH-PPV to ATO were similar (ranging from 0.77 to 0.46 ps), while the rates of the charge recombination increased at higher doping levels. The effects of the doping level on the injection and the recombination rates were discussed.