The influence of annealing atmosphere on the material properties of sol–gel derived SnO2:Sb films before and after annealing

Abstract

SnO2 films with and without Sb doping were prepared by the sol–gel spin-coating method. Material properties of the SnO2 films with different Sb contents were investigated before and after annealing under O2 or N2. When SnO2 films are annealed under N2 or O2, the resistivity decreases with increasing annealing temperature, which may be related to the increased crystallinity and reduced film defects. The intensity of SnO2 peaks for both O2- and N2-annealed films increases as the annealing temperature increases. Small nodules are revealed on the surface of SnO2 films after annealing in N2 or O2 atmospheres, and some voids are present on the surface of N2-annealed SnO2 films. After doping with Sb, the resistivity of SnO2 films after annealing in O2 is greater than that of N2-annealed SnO2 films. The surface morphology of SnO2 films incorporating different molar ratios of Sb after annealing are similar to that of as-spun SnO2 films with adding Sb. There were no voids found on the surfaces of N2-annealed SnO2:Sb films. In addition, the peak intensity of SnO2:Sb films after O2-annealing is higher than those films after N2-annealing. The chemical binding states and Hall mobility of the high-temperature annealed SnO2 films without and with adding Sb are also related to the annealing atmospheres. This study discusses the connection among the material properties of the SnO2 films with different Sb contents and how these properties are influenced by the Sb-doping concentration and the annealing atmospheres of SnO2 films.