There are several factors that limit the performance of the DSSC such as corrosion of the counter electrode by the iodide/triiodide redox couple, leakage of the electrolyte, and insufficient light absorption by sensitizers. The liquid electrolyte causes several technological issues such as desorption of the dye and degradation of the cell. The aim of this work is to investigate new electrolytes for dye sensitized solar cells (DSSCs). This research work concerns the preparation and characterization of organic salts which form ionic liquids and organic ionic plastic crystals.
The aim is to have better understanding of the properties of these materials in solar cell applications. Electrochemical methods such as cyclic voltammetry, microelectrode diffusion measurements and impedance spectroscopy are used to determine the electroactive window of the electrolytes and their transport properties respectively. The work also involves the construction of dye sensitized solar cells for the evaluation of these electrolytes. Transport properties of some ionic liquids and organic ionic plastic crystals have been studied. The diffusion coefficient of these ionic liquids and organic ionic plastic crystal are 2 order magnitudes lower than the liquid based electrolytes, but a high concentration of iodine can be used to overcome mass transport problems. In some cases, there have been formations of crystal at room temperature.