Different Morphologies of ZnO Materials: Structural and Luminescence Characteristics

Three facile and efficient fabrication methods, to synthesize ZnO materials with different morphologies have been reported here. Uniform dumbbell-like ZnO microcrystals were obtained via surfactant assisted wet chemical route when hexamethylenetetramine was added in the precursor solution while low-temperature solution route with refluxing rendered hexagonal flower-like rod aggregates. However, rapid hydrothermal route yielded microrods like morphology of ZnO. X-ray diffraction spectra confirmed crystalline wurtzite hexagonal phase for all the samples. The nature of defects in ZnO was investigated by Photoluminescence spectroscopy. It was found that fabrication methods significantly affect the defect emissions of the nanostructures. For different fabrication conditions, defect emissions in the green and yellow spectral ranges were observed. ZnO materials with resulting PL emission offer strong potential in various photonic applications such as visible wavelength phosphors.