Mixed Cations Polymer Gel Electrolytes for Quasi-Solid-State Dye-Sensitized Solar Cells

Abstract

The electrolyte acts as a charge transport mediator between the photoanode and the counter electrode of dye-sensitized solar cells (DSSCs). However, liquid electrolyte limits the lifetime of DSSCs owing to leakage and high volatility issues. Thus, polymer gel electrolytes (PGEs) have been developed to minimize these problems. In this article, PGEs have been synthesized by employing polyvinylpyrrolidone as a host polymer and potassium iodide (KI) and ammonium iodide (NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> I) as iodide salts. The PGE comprising of mixed salt (KI + NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> I) shows a higher conductivity compared with PGEs with single salt at room temperature. The ionic conductivity of PGEs directly affects the efficiency of DSSCs. The solar cell assembled with mixed salt (0.02g KI + 0.05g NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> I) PGE shows the power conversion efficiency of 0.121% superior to that of DSSCs fabricated with KI (0.061%) and NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> I (0.068%) based PGEs separately.