The compositional and structural properties of sprayed SnO 2:F thin films

Abstract

Thin films of SnO 2 doped with fluorine were produced by the conventional spraying method using Corning 7059 glass substrates. The electrical and optical properties of these films were determined as a function of the substrate temperature T s and dopant concentration in the basic spraying solution. The visible and near-IR transmittance as well as the electrical resistivity of the films decreased with an increase in the fluorine concentration. The best electro-optical properties (an average transmittance of 75% and an electrical resistivity of 10 −3 Ω cm) were achieved for 250°C⩽ T s⩽350°C and fluorine concentrations (relative to tin) in the spraying solution of around 2 at.%. The surface texture of the films was investigated by scanning electron microscopy and optical microscopy. The fluorine content of the samples was analysed by secondary ion mass spectroscopy, Auger electron spectroscopy and electron spectroscopy for chemical analysis. Structural changes were studied using X-ray diffractometry. A systematic change in the intensity of the X-ray diffraction lines as a function of the fluorine content was observed. Theoretical calculations of the structure factors associated with the SnO 2 lattice if fluorine atoms are introduced into substitutional and interstitial positions were performed.