Formation and cathodoluminescence of Al:ZnO nanoscrew clusters

Al:ZnO nanoscrew clusters were prepared by thermal evaporation at a synthesizing temperature of 500 °C. The morphology and structure of the as-synthesized nanostructures were characterized by field emission scanning electron microscopy, X-ray diffraction and transmission electron microscopy, indicating that the Al:ZnO nanostructures have a single crystalline hexagonal wurtzite structure. The proposed growth mechanism involves the formation of Al:ZnO nanoscrew clusters in a heterogeneous nucleation process. The optical properties measured by cathodoluminescence, showed that the Al:ZnO nanoscrew clusters exhibit luminescence at three wavelengths −380 nm (UV emission), 490 nm (green emission) and 764 nm (near-IR emission).