Structural, morphological and optical properties of Nickel-doped SnO2 nanostructure materials prepared by the sol-gel method under different heat treatments

This work presents a detailed study of the influence of different annealing temperatures on the structural, morphological and optical properties 5 wt% Ni doped SnO2 thin films. Ni doped SnO2 thin films were deposited by sol gel method on glass substrates and then annealed at different temperature. Structural and morphological investigations were carried out on all samples by X-ray diffraction method and atomic force microscopy while Optical properties were obtained with UV-Visible spectrophotometer. Structural analysis showed that all films are polycrystalline with rutile phase and preferred orientation (110) which improves with increasing the annealing temperature. The grain size is calculated by the Scherrer method ranges from 3.9 nm to 9.13 nm. AFM images showed that Ni doped SnO2 thin films have a smooth surface morphology with nanostructure surface roughness in the range of 12 to 25 nm. The optical properties in the visible range showed that the deposited layers have a high transmission factor. An average transmittance of > 75% was observed for all the films. The optical band gap energy vary in the range of 3.89 - 4.02 eV with the increase in annealing temperature.