Cathodoluminescence studies in a scanning electron microscope were used to investigate luminescence mechanisms. Sintered material prepared from high-purity powder was found to exhibit a strong dependence of the cathodoluminescence emission upon the heat treatments applied during preparation. Scanning electron microscopic images revealed the presence of nano and microcrystalline grains. The correlation of the grain size and morphology with the optical emission was analyzed by cathodoluminescence microscopy and spectroscopy. The main emission bands appear to be centered at about 2.58, 2.25, and 1.94eV; depending upon the sintering treatment. Cathodoluminescence images reveal that the 2.25 and the 2.58eV bands were associated with specific crystal faces. The evolution of the luminescence bands with mechanical milling revealed a complex evolution of the 1.94 and 2.58eV emissions. This was explained by the formation and recovery of defects during milling.

Cathodoluminescence of Defects in Sintered Tin Oxide. D.Maestre, A.Cremades, J.Piqueras: Journal of Applied Physics, 2004, 95[6], 3027-30