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Efficient Infrared Electroluminescent Devices Using Solution-Processed Colloidal Quantum Dots

Authors


  • The authors gratefully acknowledge Vlad Sukhovatkin, Ahmed Maria, Fred Chang, and Steve McDonald for providing the equipment for PLQE and photoconductivity measurements. We also thank Prof. Alex Shik for fruitful theoretical discussions. The authors acknowledge Materials and Manufacturing Ontario, a division of the Ontario Centres of Excellence; the Natural Sciences and Engineering Research Council of Canada through its Collaborative Research and Development Program; Nortel Networks; the Canada Foundation for Innovation; the Ontario Innovation Trust; and the Canada Research Chairs Programme.

Abstract

We report efficient electroluminescence in the near-infrared from PbS–MEH-PPV (poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene)) large-area, solution-cast nanocomposite devices. We employ multivariate optimization of the structural and materials components that govern the radiative, energy-transfer, and bipolar-injection efficiencies into the devices. As a result, we report an external electroluminescence quantum efficiency of 0.27 %, which corresponds to an internal electroluminescence quantum efficiency of 1.9 %. The very best devices exhibit internal-radiative-efficiency-limited performance and not transport- or capture-limited performance, indicating that further gains in efficiency may be achieved if the internal radiative efficiency of the nanocrystal–polymer composite can be further increased without compromising transfer and device bipolar-injection efficiency.

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