Graduation Year
2012
Document Type
Dissertation
Degree
Ph.D.
Degree Granting Department
Electrical Engineering
Major Professor
Ashok Kumar
Co-Major Professor
Jing Wang
Keywords
ALD, hydrothermal, microcontact, microfluidics, nanowires
Abstract
ZnO nanostructures have been investigated for quite a long time. However, only recently they triggered much interest due to advances in materials synthesis and characterization, as well as emerging demand for new nanostructured materials in novel device implementations.
A large part of the work was devoted to exploring new methodology for patterning growth sites and controlling nanowires morphology using the deposition methods that are compatible with integrated circuits (IC) processing. Microcontact printing was used to pattern the seeding layer, and, subsequently, ZnO nanowires through a resistless soft lithography process.
When considering hydrothermal growth of ZnO nanowires in the framework of IC compatible techniques, it is favorable to keep the chemistry of the process constant, while tailoring morphological properties of ZnO nanowires through other means. Therefore, control over morphology of ZnO nanowires was realized by setting the physical properties of seeding layers. Atomic Layer Deposition (ALD) was used to deposit seeding layer required for hydrothermal growth and the effect of the physical properties of ALD thin films on resultant ZnO nanowires was studied.
Opto-electrochemical properties of ZnO nanowires were studied in various electrolytes and performance of ZnO nanowires as an electrode material for multifunctional applications was investigated. Also, bulk nucleation and growth of novel aster-like nanostructures was investigated. These nanostructures may prove useful for creation of mechanically reinforced biocompatible polymers.
Another key objective of the present work was to create strategies for controlled growth of ZnO nanowires on substrates previously unavailable for conventional hydrothermal growth of ZnO nanowires. The newly developed approach greatly facilitates growth of ZnO nanowires in confined microstructures, which greatly enhances the possibilities for the usage of ZnO nanowires in applications where they act as a porous electrode. These novel techniques open wide possibilities for improving performance of devices such as dye sensitized solar cells or supercapacitors.
Scholar Commons Citation
Ladanov, Mikhail, "ZnO Nanostructures: Growth, Characterization and Applications" (2012). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/4353
