Optical and Structural Characterization of Dip Synthesized Al-B Co-doped ZnO Seeded Platforms for ZnO Nanostructures

Abstract

Zinc oxide and aluminum-boron co-doped zinc oxide (Al-B:ZnO) thin films have been dip coated on glass substrates using Sol-Gel technique. The ZnO solution was prepared by using zinc acetate dihydrate (ZAD) as starting material. Ethanol and citric acid were used as solvent and solution stabilizer, respectively. Doping of Al-B was achieved by adding a proper molar ratio of aluminum nitrate (Al(NO₃)₃ 9H₂O) and boric acid (H₃BO₃) to the final ZnO solution. The optical properties for the films were investigated through the UV-Vis spectrophotometry technique. The transmittance of the undoped ZnO decreases while the concentration of boron increases and it increases while the concentration of Al increases over the range of interest. The index of refraction was found to be between 1.73 and 2.43 for the undoped ZnO which agrees well with that of the bulk ZnO. It increases while the B concentration increases and it decreases while the concentration of Al increases. The structural properties were also investigated through XRD, SEM and EDAX measurements. The films acquired hexagonal structure after annealing. The films have been used as seeded platforms for growing ZnO nanostructures using hydrothermal technique and found to fit better for the ZnO platforms rather than the doped ones.

Keywords: Thin films, ZnO, Al-B co-doped ZnO, Sol gel process, Dip coating, Nanostructures, Optical properties, Structural properties.

PACS: 78, 81