The effect of annealing temperature on optical constants of zinc oxide films

The aim of this work is to investigate the optical constants of zinc oxide thin films under different post- annealing temperatures from 400 - 600ºC. The refractive index of films shows an anomalous dispersion in the spectral range about λ 400 nm and a normal dispersion in the spectral range 400 λ 500 nm and 1000 λ 1500 nm. With increasing post-annealing temperature from as-deposited films to films annealed at 500ºC, for all wavelength range, the extinction coefficient k and the imaginary parts of the complex dielectric constants ε2 decreases and then from 500 to 600ºC due to decreasing particles size it increases.