A preliminary study on structural and optical properties of heat treated NB2O5 nanostructure

Abstract

Annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to improve their crystalline structure and other important properties. This work presents the effect of post heat treatment on optical, structural, morphological, and surface roughness of Nb2O5 thin films at different temperatures (200-700oC) which to the best of our knowledge not been extensively studied yet. A clear modification in surface morphology and other studied properties was obtained. XRD results show a significant enhancement in the film’s structural properties such as a reduction in the dislocation densities and stress. The optical properties of the treated films show a clear decrease in the transmission and energy gap values which their values were found to reduce from (4.35 to 2.9) eV with heat treatment up to 600oC and re-increase at 700oC. The surface roughness was also enhanced as a result of increasing the grain size from (9.95 – 34.7) nm Finally, SEM images of the films show an obvious change in their morphology and an increase in film uniformity as a result of heat treatment. Therefore, heat treatment could be considered as a helpful method to control film characteristics. Main result should be presented quantitatively