Optoelectronic and Morphological Properties of Zinc Oxide Nanostructures Produced by Hydrothermal SynthesisShow full item record
|Optoelectronic and Morphological Properties of Zinc Oxide Nanostructures Produced by Hydrothermal Synthesis
|ZnO nanostructures with controlled morphology have a very wide range of potential applications in UV photodetectors, sensors, field effect transistors, Shottky diodes, etc. In many instances it is desirable for ZnO nanostructures of a specific geometry to be produced in large quantities, with excellent crystallinity and reproducible properties. Major challenge in this respect, however, is the low yield of most current synthesis methods. In our work, we successfully applied a low-temperature inexpensive method for synthesis of ZnO nanostructures. This approach involves hydrothermal synthesis and subsequent deposition of nanostructures on the surface of a zinc foil by immersing it in a solution of hexamethylenetetramine (HMT), zinc acetate dihydrate, ammonium hydroxide, as well as deionized water, and autoclaving for several hours. By modifying the synthesis parameters we succeeded in creating a variety of ZnO nanostructures, such as nanorods, nano-"urchins", nano-"bushels", nano-"brooms", and nanoplates. In particular, it was found that the morphology and size distribution of the synthesized product was extremely sensitive to the precursor concentrations. Autoclaving time appears to most strongly affect the final size of the obtained nanostructures. X-ray diffraction and energy-dispersive X-ray spectroscopy confirm that the products are pure and of excellent crystallinity. Photoluminescence spectroscopy measurements reveal a strong dependence of the spectral shapes on the morphology of the synthesized nanocrystals. We discuss the influence of the precursors on the growth dynamics of ZnO surfaces with different polarities as well as their implications for the electronic structure of ZnO.
|Physics and Astronomy
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- Undergraduate Honors Papers