UNDOPED AND FLUORINE-DOPED SPRAY DEPOSITED SNO2 FILMS - GROWTH AND CHARACTERIZATION

The incorporation of fluorine in SnO2 layers deposited using the spray pyrolysis technique has been studied. Fluorine doping was achieved by adding hydrofluoric acid. An anomalous behaviour of electrical properties was observed on layers grown under 350-degrees-C. Resistivities as low as 5 x 10(-4) OMEGA . cm, Hall mobilities as high as 24 cm2/V . s and effective carrier concentrations up to 10(21) cm-3 were obtained in a reproducible manner. Measured carrier concentrations were always lower than fluorine contents in the solution. Average optical transmissions on the whole visible range as high as 90% for the best conductive films, were observed for layers approximately 500 nm in thickness. The best Haacke's figures of merit were about 4 x 10(-2) OMEGA-1. These films are highly resistant to wearing conditions and chemically stables.