Title:
Synthesis, characterization and application of ZnO nanomaterials

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dc.contributor.advisor Wang, Zhong Lin
dc.contributor.author Mai, Wenjie en_US
dc.contributor.committeeMember Gall, Kenneth A.
dc.contributor.committeeMember Snyder, Robert L.
dc.contributor.committeeMember Wong, Ching-Ping
dc.contributor.committeeMember Wu, C.F. Jeff
dc.contributor.department Materials Science and Engineering en_US
dc.date.accessioned 2009-06-08T19:17:57Z
dc.date.available 2009-06-08T19:17:57Z
dc.date.issued 2009-04-03 en_US
dc.description.abstract In this thesis, high temperature vapor deposition method has been extensively used to synthesize nanomaterials. One of the as-synthesized nanostructures is superlattice-structured nanohelix, which is made of two types of alternating and periodically distributed long crystal strips. The manipulation of the nanohelix showed super-elasticity and special fracture mechanism. The other widely studied nanomaterial is vertically aligned ZnO nanowire array, which is epitaxially grown on GaN and SiC substrates. Several manipulation methods such as e-beam lithography (EBL), dielectrophoresis, and in situ direct manipulation, have been developed, so that the mechanical and electrical properties of a single nanowire can be characterized, which provide essential references for fabricating bridged nanowire based devices. Specifically, an improved atomic force microscope (AFM) based method has been developed to accurately measure the elastic modulus of bridged ZnO nanowires. Bridged nanostructure is an extremely important configuration in planar MEMS/NEMS devices and this new approach provides insights to the importance of boundary conditions. Novel physical and statistical models have been firstly developed to obtain better estimate of elastic modulus. For electrical properties of bridged nanowires, it is found that the direct contact of ZnO nanowire and Au electrodes displays a back-to-back Schottky behavior. Self-assembled monolayer (SAM) can improve the mechanical contact and increase the conductance. These devices with Schottky contacts show much better UV sensing performance than the ones with Ohmic contacts. Barrier height change is believed to play an important role in a lot of sensors. A thermionic emission-diffusion model is deduced to successfully explain the current change in a strain sensor. This thesis clearly exhibits the unique properties of ZnO nanomaterials and provides deeper understanding to methodologies as well as the phenomena. With further exploration, ZnO nanomaterials should be able to better understood and utilized, and come close to the next step of commercialization. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/28172
dc.publisher Georgia Institute of Technology en_US
dc.subject Nanomaterials en_US
dc.subject ZnO en_US
dc.subject.lcsh Nanostructured materials
dc.subject.lcsh Zinc oxide
dc.title Synthesis, characterization and application of ZnO nanomaterials en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Wang, Zhong Lin
local.contributor.corporatename School of Materials Science and Engineering
local.contributor.corporatename College of Engineering
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relation.isOrgUnitOfPublication 21b5a45b-0b8a-4b69-a36b-6556f8426a35
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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