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 (JSC) and open circuit voltage (VOC) 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.