Improved morphology and photovoltaic performance in TiO2 nanorod arrays based dye sensitized solar cells by using a seed layer

► TiO2 nanorod arrays were grown on the seeded-FTO substrate by hydrothermal method. ► TiO2 seed layer significantly increased the density and orientation of the nanorods. ► DSSC based on TiO2 nanorod arrays with seed layer exhibited an efficiency of 2.55%. Rutile TiO2 nanorod arrays were grown on TiO2 seed layer coated fluorine doped tin oxide (FTO) substrate by a hydrothermal method. The effects of the thin TiO2 seed layer on the morphology of nanorod arrays, as well as the photovoltaic performance in dye-sensitized solar cells (DSSCs) were analyzed. The introduction of the TiO2 seed layer was found to significantly increase the density and vertical orientation of the nanorod arrays, which lead to the improvement of dye absorption and electron transport. By optimized the TiCl4 solution concentration, a power conversion efficiency of 2.55% can be achieved in a DSSC fabricated by TiO2 nanorod arrays grown on seeded-FTO substrate using 0.15M TiCl4 solution, which is 126% higher than the DSSC fabricated by nanorod arrays grown on bare FTO substrate (1.13%).