Photoconductivity Studies of Treated CdSe Quantum Dot Films Exhibiting Increased Exciton Ionization Efficiency

ORAL

Abstract

We present a photocurrent study of CdSe quantum dot films exhibiting unity internal quantum efficiency as a result of post-deposition treatments. While the photocurrent of untreated films is highly voltage dependent at all voltages, the treated films depend strongly on voltage at low voltage, linearly with voltage above a voltage threshold, and finally saturate at high voltage. The voltage dependence of the treated films can be reproduced with a model assuming blocking contacts and a field dependent exciton ionization efficiency that saturates to unity. The increase in exciton ionization efficiency is a result of increased surface passivation and decreased QD spacing.

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Authors

  • Venda Porter

  • Mirna Jarosz

  • Brent Fisher

    • Department of Chemistry and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA

  • Marc Kastner

    • Department of Physics, Massachusetts Institute of Technology, Cambridge, MA

  • Moungi Bawendi

    • Department of Chemistry and Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA