The Surface Modification And Physical Characteristics Of ZnO Nanostructures

Wurzite zinc oxide have unique physical and chemical properties, study of ZnO nanostructures are currently the subject of intensive research in nanoscience. Based on that, the primary work of this thesis are as follows:The hydrothermal approach was well-chosen to prepare ZnO nanowire arrays. And the ZnO films were beforehand deposited on Si substrate by atomic layer deposition as seed layer growing. The result revealed that c-axis orientation of wurtzite structural ZnO nanowires arrays were obtain and Photoluminescence spectra show the samples have high efficiency UV emision.A two-step wet chemical method was employed to introduce sulfur element for modify the ZnO nanowires' surface which result in the Zn O/ZnS core–shell structure formation. We found that the near-band-edge(NBE) ultraviolet(UV) emission of the ZnO nanowires was enhanced by 2.5 times after coating with ZnS nanocrystal modification layer. Simultaneously, visible(surface defects-related) emission in ZnO nanowires are passivated and nearly quenched completely.The effects of annealing on structural and optical properties of ZnO/ZnS core–shell nanowires were investigated by various characterization methods. The optimal conditions that make the near-band-edge ultraviolet(UV) emission of ZnO/ZnS core–shell nanowires enhanced by 7 times than the bare ZnO nanowires have been obtain by employing annealing temperature at 250?in N2 for 30 s.