Novel quasi-cube TiO₂ nanoparticles as light-scattering layers for dye-sensitized solar cells

The microstructure design of TiO₂ nanoparticles for photoanodes is an important issue in optimization of dye-sensitized solar cell (DSSC) performance. Up to date, the nanostructured TiO₂ particles have been extensively employed as active layers. However, less attention has been focused on the development of various TiO₂ nanostructures as the light-scattering layers (LSLs). In the present work, a facile hydrothermal method was utilized to prepare quasi-cube TiO₂ (qcTiO₂) nanoparticles as the LSL for the DSSC photoanode. The anatase qcTiO₂ nanoparticles had a size distribution of 30–60 nm. The photoconversion efficiency of the cell with the qcTiO₂ LSL was enhanced 12 %, compared to the TiO₂ film without a scattering layer. The above enhancement was further vindicated by the incident photon-to-current efficiency measurement. The effect of the qcTiO₂ LSL on electron transport and charge recombination of the DSSC was studied by electrochemical impedance spectroscopy. The experiment results revealed that the enhanced photovoltaic performance is attributed to the better light-harvesting capacity, longer electron life time, and less charge recombination of the qcTiO₂ nanoparticles.