The counter electrode was placed directly on the top of the dye-sensitized TiO2film sealed with thermal adhesive film (w25 mm), and the electrolyte (0.6 M 1-methyl-3-propylimidazolium iodide (PMII), 0.10 M guanidinium thiocyanate, 0.03 M I2, 0.5 M tert-butylpyridine in acetonitrile and valeronitrile (85:15)) was injected from a hole made on the counter electrode into the space between the sandwiched cells. The currentevoltage measurements were carried out by adopting a Keithley 2400 source meter under simulated AM 1.5 G illumination (100 mW cm ?2) provided by solar simulator (9600, Oriel). A 1 KW Xenon arc lamp (6271, Oriel) was served as a light source. The incident light intensity was calibrated with an NREL standard Si solar cell. The individual dye amount absorbed on TiO2 film was determined according to the literature procedure