| In this thesis, ZnO nanocrystals with controllable morphology were synthesized by homogenous deposition method. The morphology, microstructure, phase structure and photoluminescence of sphere-, flower-, and rod-ZnO were measured and analyzed. The growth models of ZnO crystals with different shape were built up.The isotropic shape spherical ZnO was fabricated by"oriented attachment"of a lot of small ZnO nanocrystals. Organic ligands were used to bond selectively to unique crystal facets, which could change the surface free energy of ZnO nanocrystals. Therefore the growth velocity of different crystal facets was altered, which resulted in the controllable growth. The anisotropic growth was prevented by the actions of the organic ligands in aqueous solution. Consequently, monocrystal ZnO flocky-sphere was fabricated by means of three-dimensional"oriented attachment"of ZnO nanocrystal.The flower-ZnO was fabricated by the combination of"oriented attachment"and"Ostwald ripening"mechanisms. In the first stage, a lot of ZnO nanocrystals were fabricated in aqueous solution with high pH value and supersaturation, then, these ZnO nanocrystals grew in the way of"oriented attachment"aggregation. In the second stage, the pH value and supersaturation decreased with the time of reaction. These small ZnO nanocrystals grew up to the petal of flower-ZnO in the form of"Ostwald ripening". At last, the flower-ZnO was obtained.Rod-ZnO was prepared following"Ostwald ripening"mechanism. Four experiments were designed to study the effects of reaction solution, anion of Zn2+ resource, reaction temperature, surfactant and the addition way of DEA on the growth of rod-ZnO. The results indicate that the ZnO morphology was controlled through controlling the growth velocity of different crystal facets by changing the condition of experiment. The growth of rod ZnO stopped in the direction [0001], and new nuclei formed on the crystal facet (0001), then grew up to the second rod-ZnO. Multi–nodes rod-ZnO formed finally. |
