Lakehead University Library Logo
    • Login
    View Item 
    •   Knowledge Commons
    • Electronic Theses and Dissertations
    • Electronic Theses and Dissertations from 2009
    • View Item
    •   Knowledge Commons
    • Electronic Theses and Dissertations
    • Electronic Theses and Dissertations from 2009
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.
    quick search

    Browse

    All of Knowledge CommonsCommunities & CollectionsBy Issue DateAuthorTitleSubjectDisciplineAdvisorCommittee MemberThis CollectionBy Issue DateAuthorTitleSubjectDisciplineAdvisorCommittee Member

    My Account

    Login

    Statistics

    View Usage Statistics

    Microscopic modeling of high-field charge transport in amorphous selenium

    Thumbnail

    View/Open

    DarbandiA2012m-1b.pdf (2.657Mb)

    Date

    2014-01-22

    Author

    Darbandi, Ali

    Degree

    M.Sc.

    Discipline

    Physics

    Subject

    Crystalline solids
    Non-crystalline solids
    Avalanche multiplication
    Amorphous selenium

    Metadata

    Show full item record

    Abstract

    Avalanche multiplication of charge carriers as a result of successive impact ionization has led to the development of solid state avalanche photo-detectors. Crystalline based avalanche photodiodes have found a variety of applications including laser range finders and fiber optic telecommunications. Recently, there is a growing interest to employ amorphous semiconductors due to their economically favourbale costs and capability to be readily prepared in the desired size and structure with high efficiency. Selenium is the only material that has been reported to clearly feature the avalanche phenomenon in the amorphous phase in a practical electric field. Selenium based avalanche photo-diodes motivated commercialization of TV camera tubes which are capable of capturing images at extremely low light intensities. In addition, amorphous Selenium exhibits a high potential for development of x−ray and γ−ray detectors for medical imaging devices. Hence, studying the electronic properties of Selenium is worthwhile for advancement of functional amorphous materials that feature impact ionization. The energy loss mechanism that prevents the carriers from gaining sufficient kinetic energy to initiate impact ionization is inelastic scattering of electrons and holes with optical phonons. The latter interaction in Selenium is analyzed in this work. To overcome the computational difficulties, a crystalline structure of Selenium was studied, however it is of interest to extend the outcomes to amorphous phase. Here, we assume that the calculated results based on trigonal Selenium structure can be also translated into the amorphous structure. This assumption is supported by further studies of density of states and phonon density of states in both amorphous and crystalline phases of Selenium. In addition, validity of our assumption is further confirmed by simulating an amorphous Selenium structure. Volume deformation potential was studied for both trigonal and the simulated amorphous selenium.

    URI

    http://knowledgecommons.lakeheadu.ca/handle/2453/483

    Collections

    • Electronic Theses and Dissertations from 2009

    Lakehead University Library
    Contact Us | Send Feedback

     


    Lakehead University Library
    Contact Us | Send Feedback