Elsevier, Materials Chemistry and Physics: Including Materials Science Communications, 2-3(123), p. 634-638
DOI: 10.1016/j.matchemphys.2010.05.029
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Single crystalline zinc oxide (ZnO) nanoneedles have been grown on Au coated Si (1 0 0) substrates in an inert gas atmosphere by physical vapor deposition (PVD) process. A mixture of ZnO and graphite powder was used as precursor for the production of nanoneedles. Their structure has been assessed by a range of techniques including scanning electron microscope (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The synthesized ZnO nanoneedles have tip diameter around 30 nm and average length of ∼5 μm. The XRD patterns and HRTEM measurements revealed the highly crystalline phase of wurtzite single crystalline structure, with a preferred 〈0 0 0 1〉 growth direction. Field emission from these nanoneedles was investigated and a low turn on voltage of 5.07 V μm−1 at a current density of 10 μA cm−2 was observed.