Variation of Performance of Dye-Sensitized Solar Cells With the Salt Concentration of the Electrolyte

Abstract

Dye-sensitized solar cells (DSSCs) have been identified as a viable alternative for conventional solar cells. As liquid electrolyte based DSSCs have several drawbacks, attention has now been diverted toward gel polymer electrolytes (GPEs), which can be placed in between liquid electrolytes and solid electrolytes. In this study, attempts were made to investigate the effect of salt concentration of the GPE on the performance of DSSCs. The GPE used for the study consists of polyvinylidene fluoride (PVdF), ethylene carbonate (EC), propylene carbonate (PC), 1-methyl 3-propyl immidazolium iodide (1M3PII), and iodine (I2). Conductivity variation with salt concentration as well as with temperature was first investigated. DSSCs were then fabricated for all the salt concentrations to observe the relationship between salt concentration, conductivity, and performances of DSSCs. The composition 1.6 PVdF/4 EC/4 PC/1.3 1M3PII/0.1308 I2 (weight basis) exhibited the highest conductivity, and it was 3.55 × 10−3 S cm−1 at 28 °C. The sample was an anionic conductor. DSSCs fabricated with the samples having different salt concentrations showed that current density (JSC), fill factor (FF), and efficiency (η) follow the same variation that exists between conductivity and salt concentration. Open circuit voltage (VOC) seemed to be not depending on the conductivity and salt concentration very much.