• 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

    Characterization of Organic/Organic' Heterojunctions: Electronic and Optical Measurement of Ordered Interfaces and Ultrathin Film Heterojunctions

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_2287_sip1_m.pdf
    Size:
    3.567Mb
    Format:
    PDF
    Description:
    azu_etd_2287_sip1_m.pdf
    Download
    Author
    Alloway, Dana
    Issue Date
    2007
    Keywords
    organic semiconductor
    phthalocyanines
    heterojunctions
    Advisor
    Armstrong, Neal R.
    Committee Chair
    Armstrong, Neal R.
    
    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 frontier orbitals of organic semiconductors at interfaces as they relate to organic electronic device applications, both relative energy and possible relative orientations, are the focus of this work. Heterojunctions between perylenetetracarboxylicdianhydride (PTCDA) or N,N'-di-n-butylperylene bis(dicarboximide) (C4-PTCDI) and metal centered phthalocyanines, including chloroaluminum, chloroindium, zinc, and copper phthalocyanine, have been characterized with ultraviolet photoelectron spectroscopy (UPS).Organic semiconductors heterojunctions clearly demonstrate that they cannot be treated as insulators, that vacuum level shifts occur at many organic semiconductor heterojunctions, and that Fermi level alignment is achieved but the individual nature of the organic Fermi levels must considered. UPS shows that the n-type semiconductors PTCDA and C4-PTCDI have organic Fermi levels pinned at the lower edge of the LUMO. Phthalocyanines have organic Fermi levels approximately midway between the HOMO and LUMO. The same Fermi levels are applicable for organic semiconductors at interfaces with gold as with other organic semiconductors. Further, heterojunctions of the organic semiconductors on gold show that although the alignment farther from the interface is determined by Fermi level alignment, at the immediate interface the interface dipole is determined by different factors as described by the additive model of interface dipole formation which includes factors for metal surface dipole, charge transfer, and molecular dipole moments. This model and the role of the molecular dipolar have been well characterized with alkanethiol and fluorinated alkanethiol self-assembled monolayers on gold, leading to the conclusions that the effective work function of the gold surface could be modified over a range of ca. 1.5eV with the SAM dipole and that the gold-sulfur bond is largely covalent.Fluorescence spectroscopy of phthalocyanine heterojunctions with PTCDA and C4-PTCDI was able to determine favored interfacial exciton dissociation pathways, and that charge transfer dissociation to form mobile charges is favored at PTCDA heterojunctions but energy transfer to create phthalocyanine excitons dominates at C4-PTCDI heterojunctions. The wavelength and progression of fluorescence emission from monomer phthalocyanines and aggregated phthalocyanine structures was also able to characterize thin film growth and the resultant polymorphs created by vacuum deposition of phthalocyanines on KCl (100) surfaces and on PTCDA and C4-PTCDI thin films.
    Type
    text
    Electronic Dissertation
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Chemistry
    Graduate College
    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.