Structural and optical properties of ZnO thin films prepared by spin coating method

The effect of aging times of the precursor solution and the number of spin coating cycles on the structural and optical properties of ZnO thin films prepared by spin coating was investigated. The ZnO layers are deposited on glass substrates. Zinc acetate dihydrate, absolute ethanol and monoethanolamine were used as a starting material, solvent and stabilizer respectively. ZnO films were dried at 300°C and then heated at 500°C for 1h. The increase of the aging of the precursor solution and the number of spin coating cycles showed the formation of a films with preferred orientation (002) corresponding to a wurtzite phase of ZnO, indicating a good crystallization of our layers. The average optical transmittance observed for these films is higher than 90% in visible range and the energy of the optical gap is estimated to be 3.27 eV.