• 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

    Charge Transfer Processes across Organic/Electrode Interfaces in Organic Photovoltaics

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_13139_sip1_m.pdf
    Size:
    6.861Mb
    Format:
    PDF
    Download
    Author
    Lin, Hsiao-Chu
    Issue Date
    2013
    Keywords
    Chemistry
    Advisor
    Saavedra, S. Scott
    
    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
    Charge transfer efficiency at organic/electrode interfaces affects the performance organic photovoltaics (OPVs). It is hypothesized that the charge collection efficiency at organic/electrode interfaces is influenced by the structure of the first molecular layer adjacent to the electrode surface. Two differently oriented monolayers composed of two phosphonic acid (PA) functionalized zinc phthalocyanine (ZnPc) molecules, one with four PAs attached peripherally (ZnPcPA₄), one at each quadrant, and another that is functionalized with one PA (ZnPcPA), were tethered to indium tin oxide (ITO) surfaces as models for the donor/transparent conducting oxide (TCO) interface in OPVs to address the relationship between molecular orientation and electron transfer kinetics across the organic/ITO interface. The electron transfer rate constants across the monolayer/ITO interface were measured using potential modulated attenuated total reflectance (PM-ATR) spectroscopy in TE and TM polarizations, which allows rate constants to be determined for subpopulations of molecules that are oriented predominately in-plane and out-of-plane, respectively. The templating effect of the tethered monolayer on sequential layers of donor material for ZnPcPA and ZnPcPA₄ monolayers was assessed by depositing a few layers of CuPc on ZnPcPA- and ZnPcPA₄-modified ITO. The performance of OPV devices fabricated on ITO modified with these two monolayers was compared and correlated to their orientation and energy alignments with other layers in the devices. The dependence of kinetics of electron transfer on overpotential was studied using monolayer-tethered ZnPcPA on ITO. Measurements of apparent heterogeneous electron transfer rate constants (kapp) as a function of applied potential across the ZnPcPA/ITO interface were acquired using PM-ATR at various dc biases (Edc). With varying Edc imposed on the electrode, the fraction of adsorbed molecules in reduced or oxidized states is changed, and both the energetics and kinetics of the electrode reaction are affected. The results were discussed and compared to theoretical predictions. The photoinduced charge harvesting and photocurrent generation were assessed using a clicked ZnPc-perylene diimide (PDI) donor-acceptor assembly tethered to ITO via a PA anchoring group. This ZnPc-PDI donor-acceptor assembly was used to investigate the mechanism of photoinduced charge transfer and hole-capture by ITO in the presence of a solution phase redox mediator.
    Type
    text
    Electronic Dissertation
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Chemistry
    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.