ZnS overlayer on in situ chemical bath deposited CdS quantum dot-assembled TiO2 films for quantum dot-sensitized solar cells

► ZnS overlayers coated on the CdS QD-assembled TiO2 films. ► ZnS overlayers improved the cell efficiencies for all of the TiO2/CdS films. ► Dominant effects of the ZnS overlayers for two types of the TiO2/CdS films.