THE EFFECT OF CONCENTRATION OF STRUCTURE AND OPTICAL PROPERTIES OF THIN FILMS SYNTHESIZED BY SOL-GEL METHODS SPIN COATING

ZnO thin films have been successfully synthesized by the method of sol-gel spin coating and mixing processes reflux technique. Materials used Zinc acetate dehydrate Zn (CH3COOH)2 2H2O, isopropanol and diethanolamine (DEA) are respectively as base material, solvent and stabilizer. Zinc acetate dehydrate Zn (CH3COOH)2 2H2O with various concentration of 0.6 M; 0.7 M and 0.8 M dissolved by the solvent isopropanol was then stabilized with diethanolamine (DEA). The molar ratio between the DEA and ZnAc is 1: 1. ZnO thin films on a glass substrate made by spin-coating technique with a rotation speed of 5000 rpm, for 30 seconds and calcination performed by pre-heating temperature of 300oC and 500oC annealing temperature. The results of the characterization of ZnO thin films by XRD indicates all hexagonal shaped crystal structure and the small crystal size of 25.4 nm for a concentration of 0.6 M. The results of the characterization of ZnO thin films by UV-Vis showed the highest transmittance value of 59.0% for concentrations of 0.7 M and the value of the energy band gap of 3.13 eV smallest to the concentration of 0.8 M.