Shell-in-shell TiO2 hollow spheres synthesized by one-pot hydrothermal method for dye-sensitized solar cell application

A new type of shell-in-shell TiO2 hollow spheres (S@S-TiO2) featuring excellent light scattering properties were synthesized by a facile one-pot hydrothermal method followed by calcination. Various characterizations revealed that the ratio of sucrose to TiF4 in the reagents plays a key role in controlling the hollow architecture and shell thickness of the resultant S@S-TiO2 structure. The excellent light scattering property of S@S-TiO2 makes it a promising candidate for use as the scattering layer in dye-sensitized solar cells. A bilayer structured photoelectrode consisting of the S@S-TiO2 film as a scattering layer on top of the benchmark TiO2 P25 thin film exhibited an overall conversion efficiency of 9.10% under AM-1.5G one sun light intensity, in comparison with the 7.65% efficiency for a pristine P25 photoanode.