The effect of annealing temperatures on the optical parameters of NiO0.99Cu0.01 thin films

Abstract

NiO0.99Cu0.01 films have been deposited using thermal evaporation
technique on glass substrates under vacuum 10-5mbar. The thickness
of the films was 220nm. The as -deposited films were annealed to
different annealing temperatures (373, 423, and 473) K under
vacuum 10-3mbar for 1 h. The structural properties of the films were
examined using X-ray diffraction (XRD). The results show that no
clear diffraction peaks in the range 2θ= (20-50)o for the as deposited
films. On the other hand, by annealing the films to 423K in vacuum
for 1 h, a weak reflection peak attributable to cubic NiO was
detected. On heating the films at 473K for 1 h, this peak was
observed to be stronger. The most intense peak is at 2θ = 37.12o with
the preferential orientation of the films being (111) plane. The optical
properties of the films have been studied. The effect of annealing
temperature on the optical parameters of NiO0.99Cu0.01 such as
transmittance, reflectance, absorption coefficient, refractive index,
extinction coefficient, and real and imaginary parts of dielectric
constant has been reported.