From seaweeds to biopolymeric electrolytes for third generation solar cells: An intriguing approach

Renewable energy systems represent a milestone of third millennium applied scientific research. As a viable, economic and environmentally friendly alternative to the solid electrolytes currently used in dye-sensitized solar cells (DSSCs), here we propose a biopolymer derived from seaweeds, which undergoes a process of selective carboxylation to improve its transport properties. Subsequently, a chemometric approach is used to tune the amount of salts and additives, and the highest ever measured ionic conductivity for a biopolymeric solid electrolyte has been reached (5.53 ∙ 10−2 S cm−1). To make this material suitable for DSSC application, an innovative sublimation process has been developed to allow a molecule-by-molecule activation of the electrolyte, and an efficiency of 2.06% (stable in aging tests) was measured in a first device prototype. Green chemistry, low cost materials, multivariate-based preparation methods and activation via spontaneous sublimation make this investigation a concrete starting point for the new generation of solid electrolytes for DSSCs.