Surface morphologies and properties of pure and antimony-doped tin oxide films derived by sol-gel dip-coating processing

A simple laboratory technique for the routine preparation of antimony-doped tin oxide (ATO) on float glass substrates (25 mm x 76 mm x 1 mm) was described. As-prepared thin films were dried at temperature of 100 +/- 5 degrees C and annealed at temperatures of 400-550 degrees C. Microstructural and morphological analyses of as-prepared films were performed at different conditions. The evolution of grain size and the morphologies of ATO films were analyzed by means of atom force microscopy (AFM) and digital microscope. The studies suggested that higher Sb-doped level and higher annealing temperature led to a decrease in the surface roughness of the deposited films. The XRD patterns revealed that as-prepared ATO films were in the crystallization of a tetragonal rutile structure of SnO2 with highly (110) preferred orientation. Their optical properties were analyzed by U-3310 spectrophotometer. The transmission of the ATO thin films was obtained as high as 80-90% in visible region, but decreased substantially in IR region. The sheet resistance of the investigated thin films was determined by four-probe method, showing that it was about 85-100 Omega square(-1) which decreased with the increase of antimony-doped concentration. (c) 2006 Elsevier B.V. All rights reserved.