Boosting the Photovoltage of Dye-Sensitized Solar Cells with Thiolated Gold Nanoclusters

Hyunbong Choi; Yong-Siou Chen; Kevin G Stamplecoskie; Prashant V Kamat

doi:10.1021/jz502485w

Boosting the Photovoltage of Dye-Sensitized Solar Cells with Thiolated Gold Nanoclusters

J Phys Chem Lett. 2015 Jan 2;6(1):217-23. doi: 10.1021/jz502485w. Epub 2014 Dec 24.

Authors

Hyunbong Choi¹, Yong-Siou Chen¹, Kevin G Stamplecoskie¹, Prashant V Kamat¹

Affiliation

¹ Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.

PMID: 26263116
DOI: 10.1021/jz502485w

Abstract

Glutathione-capped gold nanoclusters (Aux-GSH NCs) are anchored along with a sensitizing squaraine dye on a TiO2 surface to evaluate the cosensitizing role of Au(x)-GSH NCs in dye-sensitized solar cells (DSSCs). Photoelectrochemical measurements show an increase in the photoconversion efficiency of DSSCs when both sensitizers are present. The observed photoelectrochemical improvements in cosensitized DSSCs are more than additive effects as evident from the increase in photovoltage (ΔV as high as 0.24 V) when Au(x)-GSH NCs are present. Electron equilibration and accumulation within gold nanoclusters increase the quasi-Fermi level of TiO2 closer to the conduction band and thus decrease the photovoltage penalty. A similar beneficial role of gold nanoclusters toward boosting the V(oc) and enhancing the efficiency of Ru(II) polypyridyl complex-sensitized solar cells is also discussed.

Keywords: TiO2; dye-sensitized solar cells; gold nanoclusters; photovoltage; quasi-Fermi level.