Ruthenium based nanostructures driven by morphological controls as efficient counter electrodes for dye-sensitized solar cells

We introduce a facile approach to use ruthenium dioxide (RuO₂) and ruthenium (Ru) nanostructures as effective counter electrodes instead of using platinum (Pt) for dye-sensitized solar cells (DSSCs). RuO₂ and Ru nanostructure layers on the FTO glass can be readily prepared by a simple annealing process followed by the spin coating process of the mixture solution containing amorphous RuO₂·xH₂O precursor and poly(ethylene oxide) (PEO) as a dispersion matrix at low temperature in air. The Ru metal nanostructure layer prepared by the reduction of RuO₂ with H₂ shows the highest efficiency of 6.77% in DSSC operation, which is comparable to the efficiency of the Pt electrode (7.87%).