Photoluminescence of SnO2 nanoparticles embedded in Al2O3

Tetragonal Sn nanoparticles of similar to 15 nm diameter are produced in Al2O3 by direct Sn implantation at room temperature. After thermal annealing at 1000 degrees C in oxygen, the implantation-induced amorphous region recrystallized and the Sn nanoparticles turned into SnO2 nanoparticles with an average diameter of similar to 30 nm as revealed by transmission electron microscopy. While no absorption and photoluminescence (PL) are observed from the metallic Sn nanoparticles, SnO2 nanoparticles exhibit an absorption edge at similar to 280 nm and three emission bands at 410 nm, 520 nm and 700 nm, respectively. In addition to the previously reported blue and green emission from SnO2 nanostructures, a red PL band was observed due to the unique surface state of SnO2 nanoparticles embedded in Al2O3 substrate fabricated by ion implantation.