నైరూప్య

Influence of pH on Structural and Optical Properties of Spin Coated ZnO Thin Films

S.Shankar, M.Saroja ,M.Venkatachalam , N.Muthukumarasamy , V.Kumar

Multi layer Zinc Oxide thin films with different pH were prepared by sol-gel spin coating technique. Zinc acetate dihydrate (Zn (CH3COO)2 .2H2O), monoethanolamine (MEA,H2N(CH2CH2OH) and isopropanol (CH3C2H5OH, Merck) were used to prepare the coating solution and its pH was varied by adding ammonia and was spin coated on glass substrates at 2000 rpm for 30s. After each deposition the films were pre-heated at 200°C for 10 minutes. The coating was repeated for five times. Finally the films were post heated at 450oC in air atmosphere for 60 minutes. Thickness of the films was found by surface stylus profilometer. The structural properties were investigated by using X-ray diffraction technique and grain size was calculated. The optical properties were investigated using UV-Vis spectroscopy and PL studies and the optical band gap was calculated. The influence of pH on the structural and optical properties of ZnO thin films was reported.