Use of fumed silica nanoparticles to attain polymer free novel quasi-solid state electrolyte for high-efficiency dye-sensitized solar cells

Abstract

Novel gel electrolyte is prepared by replacing conventional polymers solely by fumed silica nanoparticles. In the gel composition, ethylene carbonate and propylene carbonate are used as solvents with the tetrapropylammonium iodide/iodine redox couple. The molar ratio of total oxygen moles of ethylene carbonate and propylene carbonate to iodide moles of tetrapropylammonium iodide (O:I−) is varied from 80:1 to 40:1 and the best room temperature ionic conductivity of 6.90×10−3 S cm−1 is achieved for the system with the molar ratio at 50:1. The dye-sensitized solar cell (DSC) employing this gel electrolyte gives a light-to-electricity conversion efficiency of 7.46% under irradiation of 100 mW cm−2. The electrolyte and the fabricated DSCs are characterized using linear sweep voltammetry, FT-IR spectroscopy, current-voltage characteristics and photocurrent action spectra.