MICROSTRUCTURE EFFECTS IN MULTIDIPPED TIN OXIDE-FILMS

Porous ultrafine tin oxide films (particle size 70-90 Angstrom) have been prepared from tin alkoxide by dip coating. The influence of the number of coating applications on the thickness, microstructure, and electrical properties of multidipped tin oxide films was investigated. With an increase in the number of coating applications, the porosity of the multidipped films decreased from 60% to 12%, but the particle size of the films increased. The resistivity of the films decreased from 5.5 x 10(-2) to 5.7 x 10(-3) Omega . cm with increasing the number of coating applications from 1 to 10. This tendency of the resistivity to decrease is due to the microstructural change of the films with the number of coating applications. The microstructure, the surface structure, and the composition of the multidipped films mere investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Auger electron spectroscopy (AES).