Co-sensitized efficient dye-sensitized solar cells with TiO2 hollow sphere/nanoparticle double-layer film electrodes by Bi2S3 quantum dots and N719

Abstract

TiO2 double layer films composed of TiO2 hollow spheres as overlayer and TiO2 nanoparticles as underlayer were prepared, and Bi2S3 quantum dots have been successfully synthesized by hydrothermal method. Then the TiO2 double layer films co-sensitized by Bi2S3 QDs and N719 dye were used as photoanode in dye-sensitized solar cells. The photoelectric properties of the DSSCs, with and without Bi2S3 QDs adsorption were studied. The results shows that the η of TiO2/Bi2S3 DSSCs is enhanced with the increasing of Bi2S3 QDs amount in TiO2 film and reaches up to 7.50% when sensitization time of Bi2S3 QDs arrives at 10 min. The improvement of performance is ascribed to the higher light harvesting, and the reduction of electron recombination as well as the enhancement of electron transport with the introduction of Bi2S3 QDs.