EFFICIENCY ENHANCEMENT BY CATION EFFECT IN DSSC WITH PAN-BASED GEL/POLYMER ELECTROLYTES

The electrolyte is one of the most important components of a Dye-Sensitized Solar Cells (DSSC), since it can affect both its efficiency and stability. Lately, the research activity is focused on gel electrolytes instead of liquid ones, because they could increase the long-term stability and efficiency of the devices. The conduction of iodide ions in gel polymer electrolytes and the performance of a DSSC, containing such an electrolyte, can be enhanced by incorporating different salts. In this work, samples were prepared using PAN, ethylene carbonate (EC), Propylene carbonate (PC), an appropriate salt, and I2. The purpose of the first part of this work has been the evaluation of cation size effects in the enhancement of the efficiency of a commercial dye (D35), by preparing samples containing five different salts (LiI, NaI, KI, RbI, CsI). The second part was instead focused on the evaluation of the mixed cation effect using 6 samples containing different amounts of RbI:LiI. In this case we have used another dye (DF15), synthesized in our research group. The variation of conductivity with salts concentration has been discussed in order to understand the mechanism of iodide ion conductivity in this system. We also used transient spectroscopy to understand how the regeneration and recombination processes change using different salts in the composition of the electrolytes.