Anatase TiO2 nanowires with nanoscale whiskers for the improved photovoltaic performance in dye-sensitized solar cells

Abstract

TiO2 as an efficient electron transfer material has been widely utilized in dye-sensitized solar cells (DSSCs), and the morphology of TiO2 plays a decisive role in the performance of DSSCs. However, one-dimensional TiO2 nanowires, which are generally used as the efficient electron transport layers, have small specific surface area and low dye loading. Here, we introduce an effective and reproducible one-step hydrothermal method to prepare TiO2 nanowire with nanoscale whiskers. The synthetic sample was characterized by the field emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction. TiO2 nanowire with nanoscale whiskers has a high light scattering performance and high dye loading capacity. This novel TiO2 nanowire show a power conversion efficiency (PCE) of 4.12%, which is close to the benchmark of P25 nanoparticle usually used in DSSC fabrication. The PCE of DSSC-3 using TiO2 nanowire with nanoscale whiskers and commercial P25 double-layer photoanode has a PCE of 5.98%, showing an increase of 11.98% when compared with DSSC-2 based on pure P25 photoanode.