Study on Temperature Effect Structural and Optical Properties of Green Synthesized ZnO Nanoparticles

In this research, we studied the structural and the optical properties of zinc oxide thin films depend on temperature effect. Zinc oxide nanoparticles were synthesized by green method using Phyllanthus Emblica stem extract which was used as reducing and capping agent. The synthesized ZnO powders were fabricated films on glass substrates by the spin coating technique. The crystalline structure, surface morphology and optical properties of green synthesized ZnO films were investigated by X-ray diffractrometry (XRD), scanning electron microscopy (SEM) and UV-Vis spectroscopy at 300ºC, 400ºC, 500ºC and 600ºC. From XRD analyses, the fabricated ZnO films were polycrystalline nature with wurtize hexagonal structure and crystalline size of synthesized ZnO films were increased from 45.49 nm to 51.47 nm with increasing temperature. The surface morphology of ZnO films were study with SEM technique. In the SEM results, the average grain sizes were increased range between 130 ~ 220 nm as increasing temperature. By absorbance measurement with UV-Vis spectroscopy, the optical properties of green synthesized ZnO films varied with temperatures was studied. The band gap of ZnO films decreased with increasing temperatures but 600 °C the band gap value decrease