Improved Performance of Dye Sensitized Solar Cells with Thioacetamide as an Electrolyte Additive

Electrolyte in dye sensitized solar cells (DSSCs) dictate the energetic of the TiO2/dye/electrolyte interface and has significant impact on electron injection, charge transport and back electron transfer processes, thereby affecting efficiency of the device. Thus, electrolyte modification, especially by an additive is a potent tactic to alter the TiO2/dye/electrolyte interface properties and enhancing the efficiency of dye-sensitized solar cells. In this work an attempt has been made to modify the electrolyte by incorporating thioacetamide in it. With the addition of 0.05 M thioacetamide in standard liquid electrolyte, the current density in DSSCs increased from 10.0 to 13.9 mA cm–2, while the voltage reduced from 0.70 to 0.66 V. Consequently, photovoltaic conversion efficiency improved to 5.51 from 4.77%. Electrochemical impedance analysis reveals a positive band edge shift and a reduction in charge recombination with thioacetamide as an additive, confirming the enhancement in current density. The positive band edge shift is caused by protons that are produced in the electrolyte as a result of the chemical reaction between thioacetamide and iodine.