Combustion-Assisted Polyol Reduction Method to Prepare Highly Transparent and Efficient Pt Counter Electrodes for Bifacial Dye-Sensitized Solar Cells

A combustion-assisted polyol reduction (CPR) method has been developed to deposit electrocatalytically efficient and transparent Pt counter electrodes (CEs) for bifacial dye-sensitized solar cells (DSSCs). Compared with conventional thermal decomposition of Pt precursors, CPR allows for a decrease in reduction temperature to 150 degrees C. The low-temperature processing is attributed to adding an organic fuel, acetylacetone (Hacac), which provides extra heat to lower reduction energy. In addition, the stable Pt complexes can simultaneously be formed in ethylene glycol (EG) and Hacac system, which leads to Pt nanoparticle size regulation. A ratio of Hacac to EG is optimized to achieve excellent electrocatalytic activity and high visible light transmittance for CEs. The bifacial DSSCs fabricated with CPR-Pt CEs (EG : Hacac=1 : 16) reach efficiencies of 6.71 +/- 0.16% and 6.41 +/- 0.15% in front and back irradiations, respectively.

Automated summary

A combustion-assisted polyol reduction method has been developed for depositing efficient and transparent Pt counter electrodes in bifacial dye-sensitized solar cells. This method allows for a decrease in reduction temperature to 150 degrees C by adding a fuel that provides extra heat. The stable Pt complexes formed in the system regulate the size of Pt nanoparticles, resulting in excellent electrocatalytic activity and high visible light transmittance. Bifacial DSSCs fabricated with CPR-Pt counter electrodes reach efficiencies of 6.71% and 6.41% under front and back irradiations, respectively.