Laser Sintering of SnO2 : Sb Sol-Gel Coatings

Abstract

Sb doped sol-gel SnO2 single layers (thickness ≈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 cm2/s by CO2 laser irradiation. The laser spot was scanned in one direction at a speed of 15,000 cm/s and the sample was moved in a perpendicular one at a speed up to 250 mm/s. The temperature of the topmost 10 μm layer was monitored by a fast pyrometer (μs resolution). The following properties of the coatings have been determined: the electrical resistivity ρ, the carrier density n, and mobility μ, the structure, the thickness, the mesoscopic and micromorphology and the density. The sintering by CO2 laser radiation is mainly a thermal driven process. At T ≈500°C it allows to obtain coatings with a smaller resistivity (6.8×10−3 Ωcm) than those produced by conventional furnace firing (ρel≈2.9×10−2 Ωcm). The results are discussed in terms of particle size and packing density.