COMPARATIVE-STUDY OF SNO2-SB TRANSPARENT CONDUCTING FILMS PRODUCED BYVARIOUS COATING AND HEAT-TREATMENT TECHNIQUES

Transparent electrically conducting SnO2:Sb coatings have been prepare d by the sol-gel dip-coating process from an ethanolic solution of SnC l2(OAc)(2) and SbCl3 (5 mol%). The room temperature resistivity of the dip-coated films heat treated in a furnace or by laser IR irradiation is systematically greater than that obtained for films made by spray pyrolysis. Solution precursors and stabilisers and above all the depos ition technique are the principal factors which influence the film mor phology and hence the electrical properties. Single layers heat treate d in a furnace are porous and consist of small, spherical shaped cryst alline particles aggregated in a loose structure with a thin but dense r top layer. A model of multilayers connected electrically in parallel allows us to determine the electrical parameters of the bulk and inte rface parts of the layers. Sintering by CO2 laser irradiation increase s the particle size and the packing density resulting in a resistivity that is four times less than for the conventionally furnace heat trea ted samples. (C) 1997 Elsevier Science B.V.