Long-term Stable Dye Sensitized Solar Cells: Aqueous and Organic Based Electrolyte Systems

Abstract

In order to meet the current and future energy needs, adoption of alternative renewable energy sources is of great importance, in addition to taking over fossil fuels due to the latter’s limited supply and adverse impacts on the environment. Nowadays, dye-sensitized solar cells (DSSCs), one of many solar technologies, hold out a promising technique to harvest solar energy and convert it to electrical energy. This is due to its simplicity of manufacturing, low cost, flexibility, relatively high conversion efficiency and minimal environmental toxicity. The Grätzel group originally presented the DSSC in 1991, and since then, many research groups have made significant progress in this area. Recent reports show that DSSCs have the potential to perform very efficiently under low light conditions, which is an attracting feature for indoor applications. However, conventional DSSCs contain organic solvents that are known for their toxicity and solvent volatility that shorten the lifetime of a DSSC. As a result, the adoption of new electrolyte systems with low volatility, low toxicity while maintaining long-term stability is a promising avenue to pursue. On the eco-friendliness side, the use of water-based gelled systems is very appealing since it would lessen the toxicity effects and volatility of the electrolyte solvent. The use of Ionic liquids (ILs) is also a good approach to be employed for the latter case mentioned above. Hence, we propose to study two different types of copper-based electrolyte systems; one is in a gelled water medium and another with low-volatility organic solvent incorporating ionic liquids. Both electrolyte systems will be investigated in fully functional DSSCs under low light conditions and for a prolonged period of time.