Enhanced photovoltaic properties of dye-sensitized solar cell based on ultrathin 2D TiO2 nanostructures

Ultrathin two-dimensional (2D) TiO2 nanostructures with a thickness of similar to 5 nm and a specific surface area of 257.3 m(2) g(-1) were synthesized by a hydrothermal process. The 2D TiO2 nanostructures and P25 nanoparticles were introduced as scattering layer and underlayer to construct a bi-layer photoanode in a dye-sensitized solar cell (DSSC). The as-prepared DSSC exhibits an enhanced power conversion efficiency (5.14%), which is 23.9% higher than that of pure P25 DSSC (4.15%). Electrochemical impedance spectroscopy (EIS) indicates that DSSC based on P25-2D TiO2 nanostructures shows a longer life time and a larger recombination resistance. The enhanced photovoltaic properties are attributed to the excellent light scattering capability and high capacity for dye adsorption of 2D TiO2 nanostructures, which makes them a promising candidate as an efficient scattering layer in high-performance DSSCs. (C) 2016 Elsevier B.V. All rights reserved.