Enhanced performance of dye-sensitized solar cells by doping Au nanoparticles into photoanodes: a size effect study

Abstract

Remarkably increased power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs) is achieved by addition of small quantities of Au nanoparticles (NPs) into TiO₂ photoanodes. By doping photoanodes with different sizes of Au NPs, the PCE of cells is improved from 9.59% to 10.80% (∼13% enhancement). The maximum increases in open-circuit voltage by 6.69% and short-circuit current density by 7.71% are observed. Detailed characterization of photovoltaic characteristics, electron lifetime and recombination resistance indicates the co-contribution of the photocharging effect, plasmonic effect and scattering effect of Au NPs and their dependence on Au NP sizes. The success of this work provides a simple and generally applicable approach to enhance light harvesting and charge separation for DSSCs.