Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5367854 | Applied Surface Science | 2011 | 5 Pages |
Flower-like ZnO nanorods have been synthesized by heating a mixture of ZnO/graphite powders using the thermal evaporation and vapor transport on Si (1Â 0Â 0) substrates without any catalyst. The structures, morphologies and optical properties of the products were characterized in detail by using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Raman spectroscopy. The synthesized products consisted of large quantities of flower-like ZnO nanostructures in the form of uniform nanorods. The flower-like ZnO nanorods had high purity and well crystallized wurtzite structure, whose high crystalline quality was proved by Raman spectroscopy. The as-synthesized flower-like ZnO nanorods showed a strong ultraviolet emission at 386Â nm and a weak and broad yellow-green emission in visible spectrum in its room temperature photoluminescence (PL) spectrum. In addition, the growth mechanism of the flower-like ZnO nanorods was discussed based on the reaction conditions.
Research highlightsⶠIn this article, we synthesized flower-like ZnO nanorods on substrates by a simple thermal evaporation process without any catalysts or templates. ⶠThe PL spectrum showed that a sharp and strong UV emission band located at 386 nm together with a weak and suppressed yellow-green emission band. ⶠThe high intensity ratio of the UV peak to the defect emissions indicates fairly good crystallization of flower-like ZnO nanorods. ⶠThe Zn liquid droplets function as catalyst plays an important role in the self-catalytic VLS growth process of flower-like ZnO nanorods at low temperature deposition region. ⶠThe possible growth mechanism of these structures is investigated.