• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2017 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2017 - Mines Theses & Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Mines RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    Login

    Mines Links

    Arthur Lakes LibraryColorado School of Mines

    Statistics

    Display Statistics

    Quantum confined silicon nanoparticles in disordered matrix

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    GUAN_mines_0052E_11337.pdf
    Size:
    2.222Mb
    Format:
    PDF
    Download
    Author
    Guan, Tianyuan
    Advisor
    Collins, Reuben T.
    Date issued
    2017
    Keywords
    defect density
    photo-induced degradation
    silicon nanoparticle
    nanocrystalline silicon
    carrier transfer
    quantum confinement
    
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/11124/171781
    Abstract
    Because of the rapid development of nanoscience and nanotechnology, nanoscale materials have drawn much attention. With decreasing the size of crystals to the nanoscale, many quantum-mechanical effects become more observable and can even dominate the electronic and optical properties of the materials. Also due to the promising, tunable, optoelectronic properties and potential for efficiency improvements, quantum confined (QC) semiconductor systems have drawn much attention for device applications. One of the attractive properties arising from quantum-mechanical effects is a size tunable band-gap since the band-gap increases as crystal size shrinks to smaller than the Bohr exciton radius. Quantum confined silicon nanoparticles (SiNPs) have received considerable attention, in part because Si is abundant and non-toxic, and in part because of the historical significance of Si in the microelectronics industry. Hydrogenated amorphous silicon (a-Si:H) has an even longer history of investigation and use in applications than SiNPs. The detailed properties, however, of the hybrid of those two materials when the SiNPs are quantum confined, is still missing. The hybrid material is a nanocomposite material, often called hydrogenated nanocrystalline silicon (nc-Si:H), consisting of SiNPs embedded in an a-Si:H matrix. Conventional nc-Si:H already exists and it has previously been shown that carriers transfer from a-Si:H to SiNPs rapidly. In addition, because of this carriers transfer, conventional nc-Si:H has less photodegradation than a-Si:H [1]. However, in the growth processes of conventional nc-Si:H, the SiNPs form through spontaneous nucleation, so control of the SiNP size, surface termination, and distribution is weak and the Si nanocrystallites in conventional nc-Si:H normally are too large to exhibit quantum confinement effects. The band-gap of conventional nc-Si:H is essentially the same as crystalline silicon (c-Si) [2]. This dissertation examines the optoelectronic and defect properties of quantum confined SiNPs, conventional a-Si:H and in particular of the same SiNPs in a-Si:H (QC-nc-Si:H). With a novel deposition process, we are able to reduce the SiNP size into the quantum confined regime and embed the quantum confined SiNPs into an a-Si:H matrix. QC-nc-Si:H is found to have a band-gap larger than c-Si while smaller than a-Si:H consistent with published model results. Using this QC-nc-Si:H we have seen the photoexcited carriers generated in the aSi:H matrix transfer into SiNPs much as they did with conventional nc-Si:H. In addition, this carrier transfer process dramatically reduces photodegradation (the Staebler-Wronski effect (SWE)) in the material. The QC-nc-Si:H with properties we have explored would open up new device possibilities such as an all nanocrystalline silicon-based multi-junction thin film solar cell or an alternative emitter or collector layer for a c-Si heterojunction (HIT) cell.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2017 - Mines Theses & Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    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.