2026-09-21T04:55:16Zhttps://dspace.mit.edu/server/oai/request

oai:dspace.mit.edu:1721.1/592202022-01-13T07:54:33Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022

Joseph M. Jacobson. Joo, Jaebum Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Massachusetts Institute of Technology. Department of Materials Science and Engineering 2010-10-12T18:43:58Z 2010-10-12T18:43:58Z 2010 2010 http://hdl.handle.net/1721.1/59220 666378294 Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010. Includes bibliographical references (p. 172-182). Hydrothermal nanowire synthesis is a rapidly emerging nanowire discipline that enables low temperature growth and batch process. It has a major impact on the development of novel energy conversion devices, high density electronics, and optical devices. However, detailed growth mechanism is still in early stage of its development. This thesis presents the fundamental understanding of controlled zinc oxide nanowire synthesis in a hydrothermal system based on thermodynamic / kinetic analysis of heterogeneous chemical reactions. Governing parameters of hydrothermal growth were evaluated with experimental growth rates and calculated solubility plots. Supersaturation was shown to be a key parameter for the hydrothermal nanowire synthesis. Morphology control of the nanowire synthesis was tested with various additional cations during synthesis. Changes in morphology and aspect ratio with different cations were explained by electrostatic competing ion model. Based on experimental results and complex ion charge distribution, the growth direction was biased via electrostatic competition from cation-complexes that adsorb to the crystal in a face-specific manner, thereby reducing zinc ion-complex adsorption and suppressing growth along that face. Dynamic control of nanowire synthesis was investigated under microfluidic environment with continuous flow. Microfluidic growth conditions were analyzed with the parametric experiments and finite element modeling. Nanowire growth under complex geometry was also evaluated. This rational control of hydrothermal nanowire synthesis was applied to fabricate high efficiency alternative current electroluminescent devices, in-situ fabricated light emitting diodes, photovoltaic devices, and field emission devices. by Jaebum Joo. Ph.D. 182 p. eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Materials Science and Engineering. Rational control of hydrothermal nanowire synthesis and its applications Thesis application/pdf Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="942c919f-5a1a-450c-8f6d-14e187f3781e"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Rational control of hydrothermal nanowire synthesis and its applications</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2010</PublicationDate> <Authors> <Author> <DisplayName>Joo, Jaebum</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Materials Science and Engineering.</Keyword> <Abstract>Hydrothermal nanowire synthesis is a rapidly emerging nanowire discipline that enables low temperature growth and batch process. It has a major impact on the development of novel energy conversion devices, high density electronics, and optical devices. However, detailed growth mechanism is still in early stage of its development. This thesis presents the fundamental understanding of controlled zinc oxide nanowire synthesis in a hydrothermal system based on thermodynamic / kinetic analysis of heterogeneous chemical reactions. Governing parameters of hydrothermal growth were evaluated with experimental growth rates and calculated solubility plots. Supersaturation was shown to be a key parameter for the hydrothermal nanowire synthesis. Morphology control of the nanowire synthesis was tested with various additional cations during synthesis. Changes in morphology and aspect ratio with different cations were explained by electrostatic competing ion model. Based on experimental results and complex ion charge distribution, the growth direction was biased via electrostatic competition from cation-complexes that adsorb to the crystal in a face-specific manner, thereby reducing zinc ion-complex adsorption and suppressing growth along that face. Dynamic control of nanowire synthesis was investigated under microfluidic environment with continuous flow. Microfluidic growth conditions were analyzed with the parametric experiments and finite element modeling. Nanowire growth under complex geometry was also evaluated. This rational control of hydrothermal nanowire synthesis was applied to fabricate high efficiency alternative current electroluminescent devices, in-situ fabricated light emitting diodes, photovoltaic devices, and field emission devices.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>