The Attitude of ZnO/Al2O3 Film Produced by Ultrasonic Spray Pyrolysis Under Thermal Annealing

Impact of annealing on structural, morphological, elemental, and optical properties of bilayer ZnO/Al2O3 film has been investigated. Bilayer film has been deposited on microscope slides by ultrasonic spray pyrolysis method at 350°C substrate temperature. Then, this film has been annealed at 400°C, 500°C, and 600°C under atmospheric conditions, respectively. Structural analyses have been revealed that bilayer films have polycrystalline with hexagonal wurtzite structures of ZnO. Also, there is no other structures have been found like Zn-Al etc. Morphological and elemental analyses have been presented that the alterations of surface, and diffusions of Al to ZnO layer. Cross-sectional images have been revealed the film thickness between 0,78-1.56 m. Optical method have been used for calculation of optical band gap values of the films which are found between 3.17-3.25 eV. The results revealed that annealing leads to diffusion from the bottom layer Al2O3 of the material to the upper layer, ZnO. In addition, it was determined that the as-deposited ZnO/Al2O3 film is still leading in terms of the investigated properties.