ZnS:Mn2+ nanoparticles as compact layer to enhance the conversion efficiency of CdS QD-sensitized solar cells

The CdS quantum dots sensitized ZnO nanorods solar cells with ZnS:Mn2+ nanoparticles as compact layer were fabricated. The effects of Mn2+ doping concentration on the photovoltaic performance of ZnO/ZnS:Mn2+ photoanode were investigated. Besides the suppression of the back transfer of photoelectrons by ZnS:Mn2+ compact layer, with the increase of Mn2+ doping concentration, the energy level of conduction band of ZnS:Mn2+ nanoparticles turned lower, which is beneficial for the charge transfer from the conduction band of CdS. Thus, the photoelectric conversion efficiency of the cell with ZnS:Mn2+ (5%) exhibited ∼3.6 folds increments of as-synthesized bare ZnO solar cell.

► ZnS nanomaterial as compact layer retards the recombination of electrons.
► The conductive band of ZnS:Mn2+ nanoparticles are lower than that of ZnS.
► Conversion efficiency of the cell with ZnS:Mn2+ (5%) exhibited best performance.