A new type of transparent and low cost counter-electrode based on platinum nanoparticles for dye-sensitized solar cells

Here we report on the fabrication of a new low-cost transparent cathode based on platinum nanoparticles prepared by a bottom-up synthetic approach. Scanning Electron Microscope (SEM) images showed the platinum nanoparticles homogeneously distributed on a fluorine doped tin oxide conductive glass surface. We demonstrated that, with such a type of cathode, the solar energy conversion efficiency is the same as that obtained with a platinum sputtered counter-electrode, and is more than 50% greater than that obtained with a standard electrode, i.e. one prepared by chlorine platinum acid thermal decomposition, in similar working conditions. Using a special back-reflecting layer of silver, we improved upon the performance of a counter-electrode based on platinum sputtering, achieving an overall solar conversion efficiency of 4.75% at 100 mW cm^-2 (AM 1.5) of simulated sunlight.