A light scattering polymer gel electrolyte for high performance dye-sensitized solar cells

Abstract

In this work, a light scattering polymer gel electrolyte (LS-PGE) is fabricated by suitably mixing hierarchically structured TiO₂ microspheres and poly(lactic acid-co-glycolic acid) (PLGA). The newly synthesized TiO₂ microspheres exhibit high reflectance in the visible light region and contain nanopores inside to facilitate the ion diffusion. Also, PLGA helps the microspheres disperse in the electrolyte without precipitation and prevents the solvent from evaporating. The LS-PGE renders more efficient light harvesting than conventional scattering layers so that it can show high efficiencies of 8.2% in comparison with the liquid electrolyte of 7.7%. In view of long-term stability, the efficiencies lie in ±10% of the initial value for 1500 h under ambient conditions. Thus, the LS-PGE can replace conventional scattering layers to give compact and flexible photoanodes, and further assure long-term stability of dye-sensitized solar cells during practical operation.