ANALYSIS OF TRANSMITTANCE OF NANOSTRUCTURED ALUMINA FILMS

The optical transmittance in the range of ultraviolet light to near in frared of nanostructured alumina films after annealing at different te mperatures has been investigated. Results show that preferential orien tation of grains exists in all films. The transmittance of the films d epends mainly on the grain size, preferential orientation of grains, a nd degree of anisotropy of containing phases. A decrease in grain size and preferential orientation of grains facilitate the improvement of optical transmittance. In samples after annealing at different tempera tures, the reasons for different transmittances in the range from ultr aviolet to near infrared, and for the shift of the absorption band edg e in the ultraviolet range, are analyzed.