Effect of solvent on the key properties of Al doped ZnO films prepared by nebulized spray pyrolysis technique

Abstract

In current work, the Al doped ZnO thin films (AZO) were deposited onto glass substrates by nebulized spray pyrolysis technique using different volume of solvents (5 ml-15 ml). The effect of solvent volume on the structural, optical, morphological and electrical properties were studied. X-ray diffraction pattern confirmed that all the films are polycrystalline in nature and have hexagonal wurtzite structure with (101) plane orientation. The structural parameters such as crystallite size, dislocation density, micro strain, texture coefficient and number of crystallites per unit area were calculated from X-ray diffraction data. AFM images showed that all the AZO films have spinous and granulous structures. The transmittance values of the films were as high as 88% in the visible region from 400 to 700 nm. The band gap values of AZO thin films are found in the range from 3.34 to 3.28 eV for 5 ml-15 ml, respectively. Optical constants such as extinction coefficient, refractive index and skin depth were calculated from reflectance and absorbance spectra. The electrical properties of the thin films were studied by Hall-Effect measurements and found as n-type conductivity with high carrier concentrations (n) 3.54 x 10(20) cm(-3) and low resistivity (rho) 4.37 x 10(-3) Omega-cm at 15 ml solution. (C) 2018 Elsevier B.V. All rights reserved.