Polymer electrolytes can be used favorably in photo-electrochemical solar cells. A possible electrolyte for this purpose is a polyacrylonitrile-Mgl(2) complex with plasticizers such as ethylene carbonate and propylene carbonate The best ionic conductivity was obtained for samples containing 60 wt% of Mgl(2) salt with respect to the weight of polyacrylonitrile, for example, at 30 degrees C the conductivity is 1.9 x 10(-3) S cm(-1) The ionic contribution to the conductivity is dominant as shown by do polarization tests. Furthermore, the glass transition temperature showed a minimum, -103.0 degrees 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. (C) 2009 Elsevier Ltd All rights reserved