Optical measurements on tailored zinc oxide thin films under optimal

ZnO is synthesized by using conventional chemical route which is known as the “sol – gel” method and deposited on glass and silicon substrate. Morphological and optical properties have been investigated using XRD, AFM, FESEM and UV – vis test. In order to optimize the synthesized ZnO thin film, the ZnO thin film is coated with thin film of different thickness associated with various annealing temperature. Thicknesses of ZnO thin film coated for 3, 5 and 9 coating cycles of coating are 40 nm2, 60 nm2 and 200 nm2, respectively. The data report that the grain size of the seed solution increases from 80 nm to 110 nm as the thickness of ZnO thin film increases. As the thin film is treated with annealing temperature from 200 °C to 450 °C, the grain size of thin film also increases from 100 nm2 to 450 nm2. The RMS value of thin film also increases due to intense surface roughness on ZnO thin film. The band gap value of thin film decreased from 3.26 eV to 3.18 eV for coating ZnO thin film with thickness 40 nm2 – 200 nm2.