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dc.contributor.advisorMazumdar, Sumiten_US
dc.contributor.authorWang, Zhendong
dc.creatorWang, Zhendongen_US
dc.date.accessioned2011-12-06T13:38:50Z
dc.date.available2011-12-06T13:38:50Z
dc.date.issued2008en_US
dc.identifier.urihttp://hdl.handle.net/10150/195107
dc.description.abstractElectron-electron interaction effects play important role in the photophysics of complex organic materials such as π-conjugated polymers and single-walled carbon nanotubes. Our theoretical work within a π-electron model captures the essential mechanism of the photophysics in these apparently different π-conjugated systems. In both polymer and nanotube systems, we not only explain existing experiments but also make testable predictions. In the area of π-conjugated polymers, we develop a theory of the electronic structure and photophysics of interacting chains to understand the differences between solutions and films. While photoexcitation generates only the optical exciton in solutions, the optical exciton as well as weakly allowed excimers are generated in films. Photoinduced absorption in films is primarily from the lowest excimer. We are also able to explain peculiarities associated with photoluminescence, including delayed photoluminescence and its quenching by electric field. We thereby resolve controversies in the field that are more than a decade old. In the area of single-walled carbon nanotubes, we have investigated the exciton theory of the electronic structure of both semiconducting and metallic nanotubes. We are able to determine quantitatively the exciton energies and exciton binding energies of the nanotubes, in both longitudinal and transverse directions. Our estimate of longitudinal exciton energies and exciton binding energies of semiconducting tubes are the best quantitative fits to the experimental results to date. We also make predictions that the longitudinal exciton binding energies of metallic tubes are comparable to those of semiconducting tubes, in contradiction to recently published results. Our work demonstrates a universality in the photophysics of S-SWCNTs and PCPs that arises from their common quasi-one-dimensionality and π-conjugation.
dc.language.isoENen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectPhysicsen_US
dc.titlePhotophysics of Single-walled Carbon Nanotubes and Thin-film Conjugated Polymers Within π-electron Modelen_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.contributor.chairMazumdar, Sumiten_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberBinder, Rolfen_US
dc.contributor.committeememberLeroy, Brianen_US
dc.contributor.committeememberStafford, Charlesen_US
dc.identifier.proquest2602en_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePhDen_US
refterms.dateFOA2018-06-24T10:35:39Z
html.description.abstractElectron-electron interaction effects play important role in the photophysics of complex organic materials such as π-conjugated polymers and single-walled carbon nanotubes. Our theoretical work within a π-electron model captures the essential mechanism of the photophysics in these apparently different π-conjugated systems. In both polymer and nanotube systems, we not only explain existing experiments but also make testable predictions. In the area of π-conjugated polymers, we develop a theory of the electronic structure and photophysics of interacting chains to understand the differences between solutions and films. While photoexcitation generates only the optical exciton in solutions, the optical exciton as well as weakly allowed excimers are generated in films. Photoinduced absorption in films is primarily from the lowest excimer. We are also able to explain peculiarities associated with photoluminescence, including delayed photoluminescence and its quenching by electric field. We thereby resolve controversies in the field that are more than a decade old. In the area of single-walled carbon nanotubes, we have investigated the exciton theory of the electronic structure of both semiconducting and metallic nanotubes. We are able to determine quantitatively the exciton energies and exciton binding energies of the nanotubes, in both longitudinal and transverse directions. Our estimate of longitudinal exciton energies and exciton binding energies of semiconducting tubes are the best quantitative fits to the experimental results to date. We also make predictions that the longitudinal exciton binding energies of metallic tubes are comparable to those of semiconducting tubes, in contradiction to recently published results. Our work demonstrates a universality in the photophysics of S-SWCNTs and PCPs that arises from their common quasi-one-dimensionality and π-conjugation.


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