Preparation of hierarchical rutile TiO₂ microspheres as scattering centers for efficient dye-sensitized solar cells

Light scattering capability is a significant factor for high efficiency dye sensitized solar cells (DSSCs), which is associated with the size and morphology of nanomaterials. Here, we reported a simple hydrothermal self-assembly method to synthesize size-controlled hierarchical rutile TiO₂ microspheres (MS TiO₂). The as-prepared uniform dandelion-like MS TiO₂ were constructed with single rutile TiO₂ nanorod unit. Due to the enhanced light scattering capability, improved electron transport and reduced charge recombination, the enhanced photovoltaic performance of solar cells have been obtained with MS TiO₂ embedded in photoanodes. The resultant photovoltaic conversion efficiency up to 9.3% has been achieved, with short-circuit current density (J_SC) and open circuit voltage (V_OC) at 15.6 mA/cm² and 0.79 V, respectively, significantly higher than that of pure P25 film based photoanodes of similar thickness (7.37%). We believe this strategy would be favor for efficient DSSCs.