ZnO single-crystal films fabricated by the oxidation of zinc-implanted sapphire

Zinc oxide single-crystal films are prepared by the oxidation of zinc-implanted sapphire at 700 degrees C for 2 h in oxygen ambient. The cross-section transmission electron microscopy image and the selected-area electron diffraction (SAED) pattern show that ZnO single-crystal films are formed on the surface of the zinc-implanted sapphire substrate. The quality and excitonic properties of the single-crystal ZnO films are studied through absorption spectra, the photoluminescence spectra and resonant Raman spectrum. The mechanisms for the formation of single-crystal ZnO films are discussed.