Paramagnetic Point Defects and Charge Carriers in PbS and CdS Nanocrystal Polymer Composites

David J. Keeble, Elizabeth A. Thomsen, Alexandros Stavrinadis, Ifor D. W. Samuel, Jason M. Smith, Andrew A. R. Watt

    Research output: Contribution to journalArticlepeer-review

    18 Citations (Scopus)

    Abstract

    Using electron paramagnetic resonance we identify point defects in CdS nanocrystals. A spectrum consistent With Cd vacancies in distorted sites is observed, and evidence for S vacancies is presented. Light-induced paramagnetic states attributed to defects are also detected in PbS nanocrystals. Nanocrystal shallow donor electron states are observed in CdS composites with the Conjugated polymer poly [2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV), and show an increased g-value compared to the bulk, which is Consistent With quantum confinement. Dark state MEH-PPV polarons are observed for composites with small (3.6 nm) CdS nanocrystals.

    Original languageEnglish
    Pages (from-to)17306-17312
    Number of pages7
    JournalJournal of Physical Chemistry C
    Volume113
    Issue number40
    DOIs
    Publication statusPublished - 8 Oct 2009

    Keywords

    • LIGHT-EMITTING-DIODES
    • ELECTRON-SPIN-RESONANCE
    • QUANTUM DOTS
    • SOLAR-CELLS
    • CONDUCTING POLYMER
    • EPR
    • NANOPARTICLES
    • NANORODS
    • SULFIDE
    • DONORS

    Cite this