Controlling the microstructure of ZnO nanoparticles embedded in Sapphire by Zn ion implantation and subsequent annealing

(0 0 0 1) α-Al2O3 single crystals (sapphire) were implanted with Zn ions of 60 keV at a fluence of 1 × 1017 ions/cm2. Transmission electron microscopy and optical absorption spectroscopy studies show the formation of ZnO nanoparticles in the sapphire substrate after the implanted sample was annealed at 700 °C in oxygen ambient. The photoluminescence spectrum of the annealed sample indicates the formation of ZnO nanoparticles with perfect lattice structure. The selected-area electron diffraction pattern proves that the ZnO nanoparticles have the (0 0 0 2) orientation which follows the orientation of Al2O3 substrate. The result shows that the crystallographic orientation of nanoparticles obtained through ion implantation is defined by the substrate.