Boosting ZnO nanowire dye-sensitized solar cell efficiency by coating a porous ZnO layer on the nanowires

Abstract

Novel ZnO core/shell nanostructures were constructed by depositing a porous ZnO layer directly on the surfaces of pre-fabricated ZnO nanowires through a facile chemical method. The morphology and structure of the obtained products have been investigated by fieldemission scanning electron microscopy, high-resolution transmission electron microscopy and X-ray diffraction analysis. In these unique nanostructures, the porous overlayer exhibits a large surface area for sufficient dye loading to enhance light harvesting and the ZnO nanowire cores provide direct conduction pathways for the photogenerated electron transport to diminish the chance of electron recombination. The obtained ZnO nanostructures were used as photoanode material in dye-sensitized solar cell which showed an increase in performance of 141 % compared with an equivalent solar cell employing ZnO nanowire arrays as photoanode. This result was achieved mainly due to an increase in photogenerated current density directly resulting from improved light harvesting of the porous layer.

Recent progress in enhancing solar-to-hydrogen efficiency

“…Abe et al reported [49] the stabilization of coumarin and carbazole dyes through the insertion of an oligothiophene moiety between the donor and acceptor components of these dyes. Compared with the activities in dye sensitized solar cell research [46,50,51], dye sensitization for solar water splitting appears to be an area with challenging yet potentially transformational opportunities.…”