A multi-layer growth process is established for the growth of GaN on ZnO films and implemented to the growth of GaN around ZnO nanopillars using metalorganic vapor phase epitaxy (MOVPE). We have successfully grown GaN/ZnO coaxial nanopillar heterostructures and, furthermore, high quality single-crystal GaN nanotubes by increasing the growth temperature. Scanning electron microscopy, transmission electron microscopy, low temperature (10 K) photoluminescence spectroscopy, and high-resolution X-ray diffraction exhibit good crystalline and morphological properties of both of these structures. (c) 2008 Elsevier B.V. All rights reserved.