• Login
    View Item 
    •   Home
    • Office of Sponsored Research (OSR)
    • KAUST Funded Research
    • Publications Acknowledging KAUST Support
    • View Item
    •   Home
    • Office of Sponsored Research (OSR)
    • KAUST Funded Research
    • Publications Acknowledging KAUST Support
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of KAUSTCommunitiesIssue DateSubmit DateThis CollectionIssue DateSubmit Date

    My Account

    Login

    Quick Links

    Open Access PolicyORCID LibguideTheses and Dissertations LibguideSubmit an Item

    Statistics

    Display statistics

    Origins of Stokes shift in PbS nanocrystals

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Type
    Article
    Authors
    Voznyy, Oleksandr cc
    Levina, Larissa
    Fan, Feng-Jia
    Walters, Grant
    Fan, James Z.
    Kiani, Amirreza
    Ip, Alexander H.
    Thon, Susanna M.
    Proppe, Andrew H. cc
    Liu, Mengxia
    Sargent, Edward H. cc
    KAUST Grant Number
    KUS-11-009-21
    Date
    2017-11-02
    Online Publication Date
    2017-11-02
    Print Publication Date
    2017-12-13
    Permanent link to this record
    http://hdl.handle.net/10754/626080
    
    Metadata
    Show full item record
    Abstract
    Stokes shift, an energy difference between the excitonic absorption and emission, is a property of colloidal quantum dots (CQDs) typically ascribed to splitting between dark and bright excitons. In some materials, e.g., PbS, CuInS2, CdHgTe, a Stokes shift of up to 200 meV is observed, substantially larger than the estimates of dark-bright state splitting or vibronic relaxations. The shift origin remains highly debated, as contradictory signatures of both surface and bulk character were reported for the Stokes-shifted electronic state. Here we show that the energy transfer among CQDs in a polydispersed ensemble in solution suffices to explain the excess Stokes shift. This energy transfer is primarily due to CQD aggregation, and can be substantially eliminated by extreme dilution, higher-viscosity solvent, or better-dispersed colloids. Our findings highlight that ensemble polydispersity remains the primary source of the Stokes shift in CQDs in solution, propagating into the Stokes shift in films and the open-circuit voltage deficit in CQD solar cells. Improved synthetic control can bring notable advancements in CQD photovoltaics, and the Stokes shift continues to provide a sensitive and significant metric to monitor ensemble size distribution.
    Citation
    Voznyy O, Levina L, Fan F-J, Walters G, Fan JZ, et al. (2017) Origins of Stokes shift in PbS nanocrystals. Nano Letters. Available: http://dx.doi.org/10.1021/acs.nanolett.7b01843.
    Sponsors
    We thank Kyle Kemp, Janet Macdonald, Chih-Shan Tan and Kemar Reid for fruitful discussions. This publication is based in part on work supported by Award KUS-11-009-21, made by King Abdullah University of Science and Technology (KAUST), by the Ontario Research Fund Research Excellence Program, and by the Natural Sciences and Engineering Research Council (NSERC) of Canada Strategic Partnership Grant 478954-15.
    Publisher
    American Chemical Society (ACS)
    Journal
    Nano Letters
    DOI
    10.1021/acs.nanolett.7b01843
    ae974a485f413a2113503eed53cd6c53
    10.1021/acs.nanolett.7b01843
    Scopus Count
    Collections
    Publications Acknowledging KAUST Support

    entitlement

     
    DSpace software copyright © 2002-2022  DuraSpace
    Quick Guide | Contact Us | KAUST University Library
    Open Repository is a service hosted 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. For anonymous users the allowed maximum amount is 50 search results.

    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.