Photovoltaic conversion enhancement of TiO2 nanoparticles decorated with Au nanocrystals and sensitized with CdSe Quantum Dots and P3OT polymer

In this work, the preparation and photovoltaic conversion characterization of 10 mu m films of sensitized TiO2 is reported. The 13 nm TiO2 nanocrystals with anatase crystalline phase were deposited on an FTO substrate and decorated with Au nanocrystals and sensitized with CdSe Quantum dots (QD) and poly(3-octylthiophene) (P3OT) in different configurations. The photocurrent was measured in a three electrode electrochemical cell. The results exhibited that TiO2/Au/QD/P3OT films have the largest photocurrent, giving approximately fivefold the photocurrent of TiO2 films sensitized only with QD and near sevenfold the photocurrent of Au decorated TiO2 films. These results are attributed to the ability of the Au nanocrystals to extract electrons from QD and the photogeneration and hole transport of P3OT. Both phenomena combined with the QD's photogeneration give a great amount of electrons that increase the photocurrent generation.