Effective and rapid optical characterization of sequential multilayer metal oxide nanostructures by genetic algorithm approach

In this paper, a modified genetic algorithm (M-GA) is proposed to simultaneously determine the optical constants of each successive layer of multilayer ZnO nanostructures. The thin films were produced by different sol-gel techniques in order to use in optoelectronic applications. The multilayer pure thin films were in the form of FilmA/Substrate/FilmA and FilmA/FilmB/Substrate. Unlike conventional methods, M-GA determines optical film parameters without the need of interference fringes of the experimental optical transmittance spectrum. M-GA gives good results for multilayer and double side coated thin film systems in our calculations. R-square values higher than 0.99 are obtained for typical film thickness of a few tens of nanometers.