Solution synthesis of nanostructured transition metal chalcogenides and their electrical and thermal properties

dc.contributor.advisor Yue Wu
dc.contributor.author Zheng, Wei
dc.contributor.department Department of Chemical and Biological Engineering
dc.date 2019-09-19T12:13:54.000
dc.date.accessioned 2020-06-30T03:17:59Z
dc.date.available 2020-06-30T03:17:59Z
dc.date.copyright Wed May 01 00:00:00 UTC 2019
dc.date.embargo 2021-04-02
dc.date.issued 2019-01-01
dc.description.abstract <p>With the development of electronic devices, more electrical units need to squeeze into small packages. As a result, more heat energy will be produced in the same area and thermal management has become a more critical issue for the design of electrical devices. One protection method is to integrate the thermal switch into an electrical device, and it will cut off current when the temperature is above the operating temperature range. There are significant gaps that must be overcome before the thermal switch can be integrated into an electrical device. The performance requirements include low resistance under normal operation to reduce power consumption while turning into high resistance at the critical condition to cut off or reduce the current. It also should be self-recoverable after cooling down and have a low production cost.</p> <p>This dissertation first describes a solution-phase synthesis of iron telluride nanostructures with reversible and reproducible switching behavior between p- and n-type conduction. A proof-of-concept thermally triggered p-n diode has been demonstrated. This device has a large electrical conductivity during normal operation which can minimize power consumption. While at high temperature, it will be triggered to a p-n diode with a fast response time to temperature rising. Secondly, a large-scale solution-phase synthesis method to synthesize silver telluride based on tellurium nanowire template has also been developed. Its structural phase transition can be realized by temperature- or electrically-driven method. In addition, the threshold DC voltage is less than 1 V and can result in a sharp drop in conductance. Lastly, A new electromagnetic sensor prototype is presented by sintering electromagnetic absorption material and phase change material together. The electromagnetic absorption material will absorb electromagnetic wave in the X band and increase temperature.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/17376/
dc.identifier.articleid 8383
dc.identifier.contextkey 15016883
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/17376
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/31559
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/17376/Zheng_iastate_0097E_17889.pdf|||Fri Jan 14 21:21:30 UTC 2022
dc.subject.disciplines Chemical Engineering
dc.subject.keywords Phase change materials
dc.subject.keywords Solution synthesis
dc.subject.keywords Thermoelectric materials
dc.title Solution synthesis of nanostructured transition metal chalcogenides and their electrical and thermal properties
dc.type dissertation
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 86545861-382c-4c15-8c52-eb8e9afe6b75
thesis.degree.discipline Chemical Engineering
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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