Effect of the annealing process on the properties of ZnO thin films prepared by the sol-gel method

Abstract

This work aims to study the influence of shock/ gradual annealing temperature on the properties of ZnO thin film with different film thickness. ZnO thin films have been prepared on glass substrates using a sol-gel method deposing by dip-coating technique. Zinc acetate dihydrate, monoethanolamine, and 2-methoxyethanol were used as starting materials, stabilizer, and solvent respectively. The X-ray diffraction patterns show that all films have the wurtzite structure and the (002) diffraction peak dominated in all of them. The ZnO films with a higher thickness and annealed under thermal shock, show higher peaks intensity and lower grain size compared to the films annealed by gradually increasing temperature. Scanning electron microscopy images confirmed the results of DRX. The best electrical and optical properties have been obtained for the samples with higher thicknesses and annealed by heat shock. ZnO thin films show a resistance value of 1,296 Ω.cm and a band gap value of 3.245 eV with high transmittance (>90%).