Laser sintering of SnO2 : Sb sol-gel coatings

Sb doped sol-gel SnO2 single layers (thickness approximate to 100 nm) were prepared from alcoholic solution and deposited via a dip coating process on fused silica substrates. The coatings have been sintered at a typical rate of 10-15 cm(2)/s by CO2 laser irradiation. The laser spot was scanned in o ne direction at a speed of 15,000 cm/s and the sample was moved in a perpen dicular one at a speed up to 250 mm/s. The temperature of the topmost 10 mu m layer was monitored by a fast pyrometer (mu s resolution). The following properties of the coatings have been determined: the electrical resistivit y rho, the carrier density n, and mobility mu, the structure, the thickness , the mesoscopic and micromorphology and the density. The sintering by CO2 laser radiation is mainly athermal driven process. At T approximate to 500 degrees C it allows to obtain coatings with a smaller resistivity (6.8 x 10 (-3) Omega cm) than those produced by conventional furnace firing (rho(el) approximate to 2.9 x 10(-2) Omega cm). The results are discussed in terms o f particle size and packing density.