Growth and structural characterization of ZnO nanostructures deposited by atomic layer deposition

• Main Authors: Kung-Cheng Ho, 何恭誠
• Other Authors: Jyh-Rong Gong
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/86158889403791898620

碩士 === 中興大學 === 奈米科學研究所 === 103 === ZnO nanostructures were grown on sapphire substrates by atomic layer deposition. To enable ZnO nanostructure formation, two ZnO buffer layer structure was employed prior to the final deposition of ZnO nanostructure at 600℃. In this case, the 1st ZnO buffer layer was deposited at 300℃, while the 2nd one was deposited either at 400℃ or 600℃. The structural and chemical composition properties of ZnO nanostructures were characterized by field-emission scanning electron microscopy (FESEM), θto 2θ X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), energy dispersive spectrometer (EDS). It was found that ZnO nanowalls were formed among the nearest ZnO nanorods in the sample having 2nd ZnO buffer layer deposited at 400℃. In the sample having 600℃- deposited 2nd ZnO buffer layer, the coalescence of ZnO nanorods and ZnO embryos were observed. HRTEM observations showed the (0002) lattice image of a typical ZnO nanobullet, sampled from the ZnO nanostructure having 400℃- deposited 2nd ZnO buffer layer which also revealed the presence of Frankel partial dislocations. The (0002) HRTEM lattice image was also identified in a typical ZnO nanorod which sampled from the ZnO nanostructure having 600℃- deposited 2nd ZnO buffer layer. Based on TEM-EDS scan results of ZnO nanobullets and ZnO nanorods , it was found the O:Zn atomic ratio being 7:3 at the tips of a ZnO nanobullet and a ZnO nanorod which was attributed to the enhanced adsorption of O2 and H2O molecules at the tips.