Bilayer ZTO film was prepared in order to improve the performance of solar cells sensitized with simple organic dyes. Conductivity and transient measurements were performed on organic dye sensitized ZnO and ZTO film to understand the charge transport and recombination mechanism through dye sensitized films. Analysis of these measurements indicates the presence of traps at all energies in band gap decrease in dark conductivity, carrier life time and increase in photosensitivity after dye attachment is due to hole passivation effect. The ZTO cells has higher Voc as compared to TiO2 and ZnO based cells due to barrier layer effect of ZnO, which can depress the recombination process in DSSCs. Steady state conductivity have shown that conductivity of ZnO is large as compared to ZTO, showing fast electron transfer rate compared to ZTO film; however on the other hand, transient measurements also indicate those recombinations are depressed in ZTO film, which increases the attainable open circuit potential of the ZTO based device. ZTO cells sensitized with simple organic dyes yield higher efficiencies than corresponding TiO2 cells. Lower value of photocurrent in TiO2 and ZTO cells is related to dye, because xanthene dyes such as Rose or EY give better performance when used with ZnO rather than TiO2. EY dye gave the best performance as sensitizer with both ZnO, while RhB dye is good photosensitizer for TiO2 and ZTO. A model of band structure of DSSC is invoked to explain the effect of surface states of metal oxide material in charge recombination mechanism of photogenerated carriers at metal oxide/dye/electrolyte interface.