SnO2 hollow nanospheres enclosed by single crystalline nanoparticles for highly efficient dye-sensitized solar cells

Abstract

The amount of dye adsorption, light harvesting efficiency and the ability of charge separation and transport are three important factors to improve the light-to-electricity conversion efficiency of dye-sensitized solar cells. SnO₂ hollow nanospheres enclosed by single crystalline nanoparticles can adsorb a large amount of dye molecules due to their large specific surface area, and have a high light harvesting efficiency resulting from the light scattering and reflection abilities of their hollow morphology, as well as the efficient charge separation and transport properties of their single crystalline structure, and thus they are a favorable structure for dye-sensitized solar cells. In this paper, SnO₂ hollow nanospheres enclosed by single crystalline nanoparticles were prepared by a one step surfactant-free hydrothermal reaction. A possible growth mechanism is proposed. The dye-sensitized solar cells based on this nanostructure show a high short-circuit current intensity of 14.59 mA cm⁻² and superior light-to-electricity conversion efficiency of 6.02% due to their favorable nanostructure.