Designing Eco-Sustainable Dye-Sensitized Solar Cells by the Use of a Menthol-Based Hydrophobic Eutectic Solvent as an Effective Electrolyte Medium

The use of a hydrophobic eutectic solvent based on dl-menthol and a naturally occurring acid such as acetic acid has been tested as an eco-friendly electrolyte medium in dye-sensitized solar cells. In the presence of a de-aggregating agent and a representative hydrophobic organic photosensitizer, the corresponding devices displayed relatively good power conversion efficiencies in very thin active layers. In particular, the higher cell photovoltage detected in comparison to devices based on toxic and volatile organic compounds may stem from a more efficient interface interaction, as suggested by electrochemical impedance spectroscopy studies showing greater charge recombination resistance and electron lifetime.