| New semiconductor heterostructures are the frontier of the current research aboutsemiconductor science and technology. The new materials or devices could be found bymeans of the interface between the hetero-junctions with singular properties. TypicalII-VI compound semiconductor materials, such as ZnO and ZnS，with low dielectricconstant, high chemical stability, and excellent piezoelectric, optical and electricalproperties of their nanostructure, are widely used in a variety of light-emitting anddisplay device, photochemical catalyst and light sensors, etc. Therefore, ZnO/ZnShetero-junction structure is a key research in nanoscience.In this thesis, ZnO/ZnS heterostructure nanocones arrays were synthesized by avapor transport deposition process. The morphologies and structure of samples werecharacterized by using scanning electron microscopy, X-ray diffraction, transmissionelectron microscopy and EDX line scanning. Moreover, the field emission propertieswere studied. The morphology of the sample can be clearly observed by atransmission electron microscope, indicating that nanocone array epitaxially grows onboth sides of the microflakes. The results of transmission electron microscope andEDX line scanning show that the nanocone arrays are ZnO/ZnS hetero-junctionnanostructures, the epitaxial relationship between ZnO and ZnS can be identified as(0001)zno//(0001)zns and the axial orientation of nanocones is parallel to the(0001)zno/zns planes. In the field emission experiment, the sample shows its lowturn-on field and high field-enhancement factor, which could be attributed to theaccumulation of electrons inside the mid-layers of the side by side ZnO/ZnShetero-junction. |
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