Dye-sensitized solar cells with enhanced efficiency using hierarchical TiO2 spheres as a scattering layer

Abstract

TiO₂ microspheres with solid, core–shell and hollow chambers were synthesized by facile solvothermal alcoholysis. The TiO₂ microspheres were encapsulated between TiO₂ films comprising of tiny nanoparticles and used as a scattering layer in dye-sensitized solar cells (DSSCs). The resulting DSSCs showed increased cell efficiencies compared to those of pure TiO₂ films without any scattering layers. DSSCs with hollow microspheres as scattering layer exhibited the highest photocurrent due to the enhanced light harvesting, which could be attributed to both the multiple reflections of light in the chamber and total internal reflections. Moreover, it also facilitated electron transfer and increased the lifetime of photocharges.