A simple approach of enhancing photovoltaic performances of quasi-solid-state dye-sensitized solar cells by integrating conducting polyaniline into electrical insulating gel electrolyte

Amphiphilic poly(hydroxyethyl methacrylate/cetytrimethylammonium bromide) [poly(HEMA/CTAB)] gel with a three-dimensional framework is successfully fabricated and employed to integrate with polyaniline (PANi). The resultant PANi imbibed poly(HEMA/CTAB) gel electrolyte provides space for holding I-/I-3(-), giving a similar conduction mechanism and ionic conductivity to that of liquid system. The caged liquid electrolyte cannot leak from the three-dimensional framework of gel electrolyte under pressure of cell assembly. Fourier transform infrared spectra, X-ray diffraction patterns, cyclic voltammograms as well as electrochemical impedance spectra are employed to evaluate the molecular structure, crystallinity, and the electrochemical behaviors, showing that the combination of PANi with poly(HEMA/CTAB) results in an enhanced ionic conduction, lowered charge-transfer resistance, and extended electrocatalytic reaction toward I-/I-3(-) redox couples from Pt/gel electrolyte interface to both interface and three-dimensional framework of the gel electrolyte. The resultant quasi-solid-state dye-sensitized solar cells based on PANi imbibed poly(HEMA/CTAB) gel electrolyte shows a light-to-electric conversion efficiency of 6.68%, which higher than that from PANi-free poly(HEMA/CTAB). Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.