Journal of Colloid and Interface Science, Vol.427, 54-61, 2014
Investigation of plasmonic gold-silica core-shell nanoparticle stability in dye-sensitized solar cell applications
Plasmonic core-shell Au@SiO2 nanoparticles have previously been shown to enhance the performance of dye-sensitized solar cells (DSSCs). A thin silica coating can provide a better stability during thermal processing and chemical stability to survive the corrosive electrolyte used in DSSCs. However, the thickness and completeness of the silica shell has proven crucial for the performance of the plasmonic particles and is largely controlled by the linking chemistry between the gold core and silica shell. We have evaluated four different silica coating procedures of similar to 15 nm gold nanoparticles for usage in DSSCs. The chemical stability of these core-shell nanoparticles was assessed by dispersing the particles in iodide/triiodide electrolyte solution and the thermal stability by heating the particles up to 500 degrees C. In order to maintain stable gold cores a complete silica coating was required, which was best obtained by using a mercaptosilane as a linker. In situ TEM characterization indicated that the heating process only had minor effects on the core-shell particles. The final step was to evaluate how the stable Au@SiO2 nanoparticles were influencing a real DSSC device when mixed into the TiO2 photoanode. The plasmon-incorporated DSSCs showed a similar to 10% increase in efficiency compared to devices without core-shell nanoparticles. (C) 2013 Elsevier Inc. All rights reserved.
Keywords:Plasmon-enhancement;Core-shell;Gold nanoparticle;Thin silica shell;Chemical stability;Thermal stability;Dye-sensitized solar cell