High color purity and excellent thermostability of photoluminescence of SnO2 nanoparticles doped with Cd2+ ions

SnO2 nanoparticles doped with Cd2+ ions were synthesized from a sol–gel process and characterized with X-ray diffraction (XRD). The photoluminescence of the SnO2 nanoparticles was investigated. It was found that the SnO2 nanoparticles doped with Cd2+ ions exhibited an extremely narrow emission with full width at half maximum (FWHM) of approximately 10 nm. The Cd2+ ion-doped SnO2 nanoparticles possessed high thermostability with respect to the pure SnO2 nanoparticles. After annealed for 2 h at 300 °C, the emission intensity of Cd2+ ion-doped SnO2 nanoparticles (0.5 mol% Cd2+) basically held the line, while the emission intensity of pure nanoparticles decreased by approximately 40%. The effect of dopant amount on the emission thermostability of the SnO2 nanoparticles was also explored.