Free-radical photopolymerization of acrylic/methacrylic polymer electrolyte membranes for dye-sensitized solar cells

As a feasible option for photovoltaic technology to meet the growing energy demand, dye-sensitized solar cells (DSSCs) have attracted much attention due to their low cost, ease of fabrication and good performance. Their relevant technological drawbacks are poor long-term stability, difficulty in hermetic sealing, electrolyte evaporation, and permeability to H2O/O2. These problems can be solved replacing the traditional liquid electrolyte with (quasi)-solid polymer electrolytes. In this work, we highlight the great potential of free-radical photopolymerization as a method of preparation of quasi-solid polymer electrolytes [1]. This process is very rapid, cheap, consistent with the main canons of green-chemistry (solvents and catalysts are not required), and could be easily transferred to industrial scale. Polyethylene glycol diacrylate (PEGDA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) were reacted under UV light in an appropriate ratio in order to obtain crosslinked, flexible and transparent membranes, subsequently activated with a I-/I3-/CH3CN solution. The entire process of preparation of these quasi-solid electrolytes lasted only 7 minutes, and a light-to-electricity conversion efficiency of 4.41% was obtained. An accurate characterization of the UV-cured membranes and the photo-electrochemical device was performed and will be here thoroughly discussed.