Photochemically produced quasi-linear copolymers for stable and efficient electrolytes in dye-sensitized solar cells

Dye-sensitized solar cells are increasingly establishing themselves as third generation photovoltaic technology which can be manufactured with easily available materials and low-cost processes. In this context, the replacement of the liquid electrolyte with quasi-linear polymer electrolyte membranes is here proposed, with the aim of increasing the durability of the device. The membranes are photochemically produced starting from two methacrylic monomers, by means of a process that does not involve the use of solvents and catalysts. In order to ensure handling and durability, the membranes are partially crosslinked with a tunable opening of the epoxy ring of one of the two monomers, thus binding together different polymer chains and allowing an effective entrapment of the redox mediator within the network. The experimental conditions are investigated and optimized by means of a multivariate chemometric approach, and the characterization of materials and devices is presented. Quasi-solid cells able to maintain efficiency up to 4% after 500 h of accelerated ageing are successfully fabricated.