Titanium dioxide nanowires modified tin oxide hollow spheres for dye-sensitized solar cells

Abstract

Tin oxide (SnO 2 ) hollow spheres modified with titanium dioxide (TiO 2 ) nanowires (NWs) synthesized by sequential hydrothermal reactions were investigated as photoanodes for dye-sensitized solar cells. Not only does the hydrothermal treatment form numerous short TiO 2 NWs on the surface of SnO 2 spheres, but also passivates the surface of SnO 2 . Consequently, the specific surface area of the photoanode and dye loading are almost doubled, at the same time the surface defects and charge recombination are both appreciably reduced. As a result, the short-circuit photocurrent density and open-circuit photovoltage both greatly increased. The power conversion efficiency of the solar cells increases from 0.4% to 2.9%.