| The main purpose of this dissertation is to synthesize novelquasi-one-dimensional semiconducting nano-materials. Based on the deepunderstanding to the research work in this area, we investigated the synthesismethod of the quasi-one-dimensional nanostructure and properities for ZnO andZnS.The quasi-one-dimensional nano-structures of ZnO with variousmorphologies and Mn-doped ZnS nanowires and nanobelts with peculiarmorphology in large quantities were successfully synthesized via catalyst-freethermal evaporation. The synthesized ZnO nanostructures include: nano-lotus-seed-pods, nano-towers, nano-magic-pestles, nano-Chinese-cabbages,nano-copper-cash, nano-tubes, nano-pectinate-rings and springs, etc.. Thevarious morphologies were characterized by scanning electronic microscope andtheir growth mechanisms were discussed respectively.ZnO nano-lotus-seed-pod structure is the most novel nanostructure amongthe nanostructures obtained, and is successfully synthesized for the first time inthe world. The scanning electronic microscope analyzed indicated that thelotus-seed-pods orientationally grow on the silicon substrate and on thenanobridges. The average diameter of the ZnO nanostructures is 2 μm. Thelotus-seed-pod ZnO structures were formed by nanorods arrays with the averagediameter of 70 nm. The analyses of XRD and Raman spectra show that they arehigh purity ZnO crystals with wurtzite nanostructure grown along c-axis.We measured the field-emission properties and PL properties of the ZnOnano-lotus-seed-pods and surprisedly discovered that they have excellentfield-emission properties with very high maximum current density of 12.4mA/cm~2 and η of 9.27% related with the electron field emission efficiency,which is higher than these of ZnO nanostructures with other morphologies. Inaddition they have low turn-on field of 3.4 V/μm , low threshold field of 7.3V/μm and high field enhancement factorβ.
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