New Type of Core-Shell Nanocrystal Quantum Dots for Applications in Light Emitting Diodes (LEDs)

ORAL

Abstract

We demonstrate a proof of principle for LEDs based on giant nanocrystal quantum dots (g-NQDs). These dots consist of a CdSe core overcoated with a thick CdS shell built one monolayer at a time. Our device structure is composed only of a PEDOT:PSS coated indium-tin oxide (ITO) anode and a LiF-Al cathode. These simple devices exhibit a maximum external quantum efficiency (EQE) and luminance of 0.12{\%} and 1000 Cd/m2 respectively when 16 shell g-NQDs are used for the active layer. This performance is already comparable to that of more sophisticated all-inorganic NQD LEDs. Thick shell ($>$13 monolayer) g-NQD devices show EQEs about one order of magnitude higher than those of thin-shell (4 monolayer) NQD devices, as well as much greater stability for operation under ambient conditions. Although current g-NQD devices do not set any new performance records, this work demonstrates a significant potential of g-NQDs for LED applications.

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Authors

  • B.N. Pal

    • LANL

  • S. Brovelli

    • Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
    • LANL

  • Y. Gosh

    • LANL

  • V.I. Klimov

    • Los Alamos National Laboratory
    • Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
    • Los Alamos National Lab
    • LANL

  • J.A. Hollingsworth

    • Los Alamos National Lab
    • LANL

  • H. Htoon

    • LANL
    • CINT, Los Alamos National Laboratory
    • Los Alamos National Lab