Effects of heat treatment on fluorine-doped tin oxide anti-reflection films coated on silicon spheres

Abstract

Fluorine-doped tin oxide (SnO_x:F_y) anti-reflection films coated on the surface of silicon spheres were investigated to clarify the effects of heat treatment on the microstructure and optical properties of the SnO_x:F_y films. The lattice constants, crystallite size, and bandgap of the SnO_x:F_y films depended on both heat treatment temperature and time. Fluorescence spectra of the SnO_x:F_y films showed a broad luminescence peak associated with point defects in the films. These results were attributed to the dependence of the O and F contents in the SnO_x:F_y crystals on heat treatment conditions.