M. Shaheer Akhtar, J-M Chun, H-C Lee, K-J Kim and O-B Yang
dye sensitization, solar cells, electrolyte, solid state
The replacement of liquid electrolyte in dye sensitized solar cells by gel and solid electrolyte is one approach towards the improvement of properties of electrolyte such as leakage and evaporation of liquid to operate for long term life. Recently, solid polymer electrolytes (SPEs) have received considerable attention in order to improve the ionic conductivity, thermal stability and mechanical properties of polymer to achieve high-energy, high current density and leakage of liquid electrolyte. Polymer based electrolytes have displayed a low ionic conductivity at room temperature which is responsible for conduction of ion or charge transport. Highly cross linked polymers have been appeared to be effective in enhancing ion conductivity, better mechanical stability and also good water absorbent, and improving the interfacial contact with electrode. In this paper, we attempted to synthesize highly cross linked polymer with poly (ethylene glycol) methyl ether (PEGME) and poly ethylene glycol (PEG) in presence of inorganic salts by chemical method and used as polymer electrolyte with the addition of iodide couple. This electrolyte is showing ambient ionic conductivity of 2.35 mS/cm, it is comparably well high to reported electrolyte. Solid state dye sensitized solar were fabricated with this polymer electrolyte and achieved an open circuit voltage of 0.616 volt, short circuit current of 8.96 mA/cm2 and over all conversion efficiency of about 3% under light intensity of 100mW/cm2. Highly crosslinking polymers in electrolyte provides the easy solidification of the electrolyte and make a good interfacial contact of electrolyte to TiO2 layer in PV cell which improve the long term stability of cells. The prepared composite materials were characterized by XRD, FT-IR, DSC, conductivity and photovoltaic performance tests.