Abstarct: In this experimental work we have studied the structural, optical and electrical properties of thin (~100-200 nm) ZnO films grown by spray pyrolysis method. Through these depositions we have used a 0.2 M zinc acetate solution sprayed on glass substrate at 450 °C with various impurity contents of Al, Ga and In with different concentragions of 1, 2 and 3 weight percents. We also tried to find the effect of Vacuum annealing process on the physical properties of these laxyers. For structural, optical and electrical properties we have used the X-ray diffractometer (XRD), UV-Vis. spectrophotometer and Hall effect set up experiments. We found the as-grown samples have a polycrystalline nature with Wurtzite Structure and pereferential (002) orientaion and relatively high transmisivity of ~ 90 %. Data analysis in pure sample showed that while contains crystallite size of ~ 27 nm, it has a wide bandgap of 3.27 eV with a band tail width of ~ 120 meV. In doped samples we found depending on the impurity, samples with 1 wt% Al, 2 wt% Ga and 2 wt% In have the highest figure of merits among other samples in their group. Experimental data also revealed that annealing process lead to samples with lower transmisivity, bandgap and sheet resistance, but tend to higher band tail width and figure of merits.