The transport and recombination kinetics in dye-sensitized solar cells with different nanoporous films

The high light-to-energy conversion efficiencies achieved with dye-sensitized solar cells may be attributed to the nanoporous TiO2 electrodes. Nanoporous electrode films are prepared from different sized anatase TiO2 nanoparticles, of which the crystalline size is 13.4 and 17.5 m, and DSCs are prepared from these films. Intensity modulated photocurrent spectroscopy has been used to obtain values of the electron diffusion coefficient. Intensity modulated photovoltage spectroscopy is shown to be valuable in achieving the different electron lifetime during the electron transport process resulting from different crystalline size and thickness of TiO2 films. The transport and recombination kinetics was discussed by investigating the change of the absorption coefficient, electron diffusion coefficient and electron lifetime in the cells. The results implied that the films morphology influence the electron transport and back reaction processes.