Efficiency enhancement of photovoltaic performance of quasi-solid state dye sensitized solar cell with TPAI and KI binary iodide salt mixture

Abstract

Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells (DSSCs) containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, were prepared by solution cast technique, based on PVP-co-VAc + PMMA host polymers and mixture of salts Potassium iodide (KI) and tetrapropyl ammonium iodide (TPAI) salts have been used to provide the conducting ions. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrochemical impedance spectroscopy (EIS) measurements showed that the electrolyte (C6) which contain (KI%25: 5%TPAI) have highest conductivity S/cm at 298 K. The DSSCs with TPAI or KI as the only iodide salt showed the efficiencies 4.136%and 2.532 %, respectively, under AM 1.5(1000 Wm^-2) illumination  while the DSSC with mixed cations with (TPAI25%:KI5%) molar ratio shows the  efficiency of 3.179%.

Keywords: Binary Iodide, Gel Polymer Electrolyte, Dye-Sensitized Solar Cells, Electrochemical Impedance Spectroscopy.