Influence of substrate temperature on the properties of CeO2 thin films by simple nebulizer spray pyrolysis technique

Abstract

Cerium oxide thin films are coated on glass substrates by nebulizer spray pyrolysis technique using cerium nitrate as a source material. Their crystallographic structures, surface morphology, optical properties and I–V characteristics are studied as a function of substrate temperature (300–500 °C). XRD is used to estimate the crystallographic texture, grain size, strain and lattice constants. All the films exhibit a cubic fluorite structure with different preferred orientations depending on the preparation conditions. Optical analysis reveals that the films are transparent (70%) in the visible region. The optical bandgap (Eg) is calculated in the range 3.28–3.52 eV. The optical parameters like absorption coefficient, extinction coefficient, packing density and refractive index are calculated for different substrate temperatures. SEM images exhibit golf-ball like morphology with small cracks and pores. The maximum conductivity obtained is 2.90×10−6 S/cm at 400 °C.