Photoelectrochemical effects of hyperbranched polyglycerol in gel electrolytes on the performance of dye-sensitized solar cells

A gel electrolyte containing hyperbranched polyglycerol (HPG) was prepared for use in dye-sensitized solar cells (DSSCs) applications, and the effects of HPG on DSSCs performance were studied. The open circuit voltage increased proportionally to HPG composition and the short circuit current increased at optimized HPG ratio due to the expansion of carrier transfer channel and the rapid salt dissociation effects of HPG. Electrochemical impedance spectroscopy of the DSSCs indicated that incorporation of HPG improved the charge transfer properties of the gel electrolytes. Overall, the optimized DSSCs yielded an energy conversion efficiency of 6.78% at 1 sun, with good long-term stability.