Gel polymer electrolyte based on poly(acrylonitrile-co-styrene)/NaI+I-2 and binary solvent mixture was prepared. When the system contains 0.5 M NaI and 0.05 M I-2, the maximum ionic conductivity (at 30 degrees C) of 2.37 mS cm(-1) was achieved. Based on a gel polymer electrolyte with 0.5 M NaI, 0.05 M I-2, and 0.5 M 4-tert-butylpyridine, a quasi-solid state dye-sensitized solar cell was fabricated and its overall energy conversion efficiency of light-to-electricity of 2.75% was achieved under irradiation of 60 MW cm(-2). (c) 2006 Elsevier Ltd. All rights reserved.