• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Photophysics of C60 Colloids

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_12458_sip1_m.pdf
    Size:
    5.306Mb
    Format:
    PDF
    Download
    Author
    Clements, Andrew Franklin
    Issue Date
    2012
    Keywords
    nonlinear scattering
    reverse saturable absorption
    total scattering
    Optical Sciences
    Buckminsterfullerene
    C₆₀
    Advisor
    Kost, Alan
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © 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.
    Abstract
    The goal of this dissertation is to study the photophysics of suspensions of colloidal C₆₀ particles to determine if their nonlinear optical (NLO) response is superior in any way to benchmark NLO materials such as molecular solutions of C₆₀ and carbon black suspensions (CBS). C₆₀ in molecular form is known to exhibit strong reverse saturable absorption (RSA) and it is posited that colloidal particles composed of many C₆₀ molecules would maintain some degree of RSA behavior upon association, although some quenching is to be expected. CBS is known to have an NLO response that is dominated by nonlinear scattering resulting from a phase change due to heating of the carbon black particles by absorbed energy. Colloidal C₆₀ particles that are many nanometers in diameter are similar to CBS, so it is posited that they would also have a nonlinear scattering mechanism contributing to their NLO response. Three samples of C₆₀ colloids are characterized by several techniques, along with two carbon black suspensions and one molecular solution of C₆₀. Transmission electron microscopy is used to determine morphology. Femtosecond pump-probe spectroscopy is used to determine the absorption spectrum and the relaxation kinetics of the first excited singlet state. Nanosecond laser flash photolysis is used to determine the absorption spectrum and the relaxation kinetics of the first excited triplet state. Z-scan is used to determine triplet-triplet absorption cross-sections. An experiment is performed to determine the percentage of the input energy that is transmitted, scattered, or absorbed by each sample. Computer modeling is performed to compare the experimental results to theory. Results show that all materials that exhibit nonlinear scattering have a constant extinction coefficient in the nonlinear regime, implying a characteristic size for the scattering centers that is independent of input energy. Quenching processes in C₆₀ colloids are found to be morphology dependent, with more crystalline structures resulting in stronger quenching and less RSA. C₆₀ colloids with stronger RSA are found to result in less nonlinear scattering than strongly quenched colloids. Highly crystalline C₆₀ colloids were shown to have a stronger NLO response than the benchmark materials at medium to high energies.
    Type
    text
    Electronic Dissertation
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Optical Sciences
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.