Dye sensitized solar cells with poly(acrylonitrile) based plasticized electrolyte containing MgI2

Polymer electrolytes can be used favorably in photo-electrochemical solar cells. A possible electrolyte for this purpose is a polyacrylonitrile–MgI2 complex with plasticizers such as ethylene carbonate and propylene carbonate. The best ionic conductivity was obtained for samples containing 60 wt% of MgI2 salt with respect to the weight of polyacrylonitrile, for example, at 30 °C the conductivity is 1.9 × 10−3 S cm−1. The ionic contribution to the conductivity is dominant as shown by dc polarization tests. Furthermore, the glass transition temperature showed a minimum, −103.0 °C, for the sample with the highest conductivity indicating the importance of polymer chain flexibility for the conduction process. Measurements on a fabricated solar cell with this electrolyte exhibited an overall energy conversion efficiency of 0.84%. The short circuit current density, open circuit voltage and fill factor of the cell were 2.04 mA cm−2, 692 mV and 59.3%, respectively.