Synthesis and photoluminescence of SnO2/SiO2 microrings

A simple two-step heat-treatment process is used to create SnO2/SiO2 microrings. SnO2/SiO2 nanoparticles obtained in the first step are transformed into microrings (see Figure) in the second step owing to their low melting point and a decrease in the surface energy of the system. The SnO2/SiO2 microrings show favorable UV photoluminescence and may be used as UV laser emitters.