Photoluminescence of SnO2nanoparticles embedded in Al2O3

Tetragonal Sn nanoparticles of ∼15 nm diameter are produced in Al 2 O 3 by direct Sn implantation at room temperature. After thermal annealing at 1000 °C in oxygen, the implantation-induced amorphous region recrystallized and the Sn nanoparticles turned into SnO 2 nanoparticles with an average diameter of ∼30 nm as revealed by transmission electron microscopy. While no absorption and photoluminescence (PL) are observed from the metallic Sn nanoparticles, SnO 2 nanoparticles exhibit an absorption edge at ∼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 SnO 2 nanostructures, a red PL band was observed due to the unique surface state of SnO 2 nanoparticles embedded in Al 2 O 3 substrate fabricated by ion implantation.