Novel quasi-cube TiO_2 nanoparticles as light-scattering layers for dye-sensitized solar cells

摘要

The microstructure design of TiO_2 nanoparticles for photoanodes is an important issue in optimization of dye-sensitized solar cell (DSSC) performance. Up to date, the nanostructured TiO_2 particles have been extensively employed as active layers. However, less attention has been focused on the development of various TiO_2 nanostructures as the light-scattering layers (LSLs). In the present work, a facile hydrothermal method was utilized to prepare quasi-cube TiO_2 (qcTiO_2) nanoparticles as the LSL for the DSSC photoanode. The anatase qcTiO_2 nanoparticles had a size distribution of 30-60 nm. The photoconversion efficiency of the cell with the qcTiO_2 LSL was enhanced 12 , compared to the TiO_2 film without a scattering layer. The above enhancement was further vindicated by the incident photon-to-current efficiency measurement. The effect of the qcTiO_2 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 qcTiO_2 nanoparticles.