ZnO nanoparticles embedded in sapphire fabricated by ion implantation and annealing

ZnO nanoparticles were fabricated in sapphire (α-Al(2)O(3) single crystal) by Zn ion implantation (48?keV) at an ion fluence of 1 × 10(17)?cm(-2) and subsequent thermal annealing in a flowing oxygen atmosphere. Transmission electron microscopy (TEM) analysis revealed that metallic Zn nanoparticles of 3-10?nm in dimensions formed in the as-implanted sample and that ZnO nanoparticles of 10-12?nm in dimensions formed after annealing at 600?°C. A broad absorption band, peaked at 280?nm, appeared in the as-implanted crystal, due to surface plasma resonance (SPR) absorption of metallic Zn nanoparticles. After annealing at 600?°C, ZnO nanoparticles resulted in an exciton absorption peak at 360?nm. The photoluminescence (PL) of the as-implanted sample was very weak when using a He-Cd 325?nm line as the excitation source. However, two emission peaks appeared in the PL spectrum of ZnO nanopraticles, i.e., one ultraviolet (UV) peak at 370?nm and the other a green peak at 500?nm. The emission at 500?nm is stronger and has potential applications in green/blue light-emitting devices.