The crystal structure of representative thin films was carried
out by XRD as shown in Fig. 1a. Figure depicts the X-ray diffraction
(XRD) patterns of ZnO films with various Sn doping concentrations.
All diffraction peaks can be attributed to polycrystalline with hex-agonal wurtzite structure. The data are in agreement with the PDF
# 891397 data files. The crystallite size of the films was calculated
by using Debye Scherer formula