Fiber-like stripe ATO (SnO2:Sb) nanostructured thin films grown by sol-gel method: Optical, topographical and electrical properties

Sb-doped SnO2 thin films were deposited on glass substrates by sol-gel dip coating technique. The effects of dopant concentration on structural, morphological, electrical, and optical properties of ATO thin films were investigated. The compositional analysis of the films carried out by using EDX and XPS. The analyses confirmed the presence of Sb in SnO2 thin films. The XRD results showed a tetragonal rutile structure of SnO2 and the crystallite size of the films decreased with increasing dopant concentration. The surface morphology of the films is found to depend on the doping concentration. The wrinkle network with uniformly protruding fiber like stripes arranged randomly on the film surface can be observed at a higher Sb content (above 7 mol%). The surface topographical image exhibited that the surface roughness of films increased by Sb doping. A minimum resistivity of 1.72 x 10(-2) Omega cm was obtained for the ATO (10 mol% Sb) film. The Hall mobility of the ATO films decreased with increasing the Sb concentration. The optical study revealed that transmittance of the films was diminished by doping and also a gradual increase in the optical band gap was observed by enhancement of dopant concentration. The compositional dependence of optical parameters such as refractive index, extinction coefficient, dispersion energy, real and imaginary parts of the dielectric constant and optical conductivity were also investigated. The PL measurements illustrated the photoluminescence quenching with increasing Sb content up to 10 mol%. (C) 2013 Elsevier B.V. All rights reserved.