Letter | Published:

Solution-processed, high-performance light-emitting diodes based on quantum dots

Nature volume 515, pages 9699 (06 November 2014) | Download Citation


Solution-processed optoelectronic and electronic devices are attractive owing to the potential for low-cost fabrication of large-area devices and the compatibility with lightweight, flexible plastic substrates. Solution-processed light-emitting diodes (LEDs) using conjugated polymers or quantum dots as emitters have attracted great interest over the past two decades1,2. However, the overall performance of solution-processed LEDs2,3,4,5—including their efficiency, efficiency roll-off at high current densities, turn-on voltage and lifetime under operational conditions—remains inferior to that of the best vacuum-deposited organic LEDs6,7,8. Here we report a solution-processed, multilayer quantum-dot-based LED with excellent performance and reproducibility. It exhibits colour-saturated deep-red emission, sub-bandgap turn-on at 1.7 volts, high external quantum efficiencies of up to 20.5 per cent, low efficiency roll-off (up to 15.1 per cent of the external quantum efficiency at 100 mA cm−2), and a long operational lifetime of more than 100,000 hours at 100 cd m−2, making this device the best-performing solution-processed red LED so far, comparable to state-of-the-art vacuum-deposited organic LEDs2,3,4,5,6,7,8. This optoelectronic performance is achieved by inserting an insulating layer between the quantum dot layer and the oxide electron-transport layer to optimize charge balance in the device and preserve the superior emissive properties of the quantum dots. We anticipate that our results will be a starting point for further research, leading to high-performance, all-solution-processed quantum-dot-based LEDs ideal for next-generation display and solid-state lighting technologies.

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This work is financially supported by the National High Technology Research and Development Program of China (2011AA050520), the National Natural Science Foundation of China (21233005 and 51172203), the Natural Science Funds for Distinguished Young Scholar of Zhejiang Province (R4110189), the Public Welfare Project of Zhejiang Province (2013C31057), the Jiangsu Natural Science Foundation (BK20130006 and BK20131413), the National Basic Research Program of China (2015CB932200) and the Jiangsu Specially-Appointed Professor programme. We thank L. Liao and L. Zhang for assistance in cross-measuring the QLED and OLED devices. We thank Q. Chen for assistance with atomic force microscopy and scanning Kelvin probe microscopy measurements. We thank Z. Zhang and C. Jin for assistance with cross-sectional transmission electron microscopy experiments. We also thank J. Yu and G. Qian for assistance in obtaining the confocal images.

Author information


  1. Center for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Cyrus Tang Center for Sensor Materials and Applications, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China

    • Xingliang Dai
    • , Yizheng Jin
    •  & Xiaoyong Liang
  2. Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China

    • Zhenxing Zhang
    • , Yuan Niu
    • , Hujia Cao
    •  & Xiaogang Peng
  3. i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 398 Ruoshui Road, Suzhou Industrial Park, Suzhou 215123, China

    • Liwei Chen
  4. Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), National Jiangsu Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China

    • Jianpu Wang


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Y.J. and X.P. had the idea for and designed the experiments and supervised the work. X.D. carried out the device fabrication and characterizations. Z.Z. conducted the optical measurements and participated in device fabrication. Y.N. and H.C. synthesized the quantum dots. X.L. and L.C. carried out the atomic force microscopy and scanning Kelvin probe microscopy experiments. Y.J. wrote the first draft of the manuscript. X.P. and J.W. provided major revisions. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Yizheng Jin or Xiaogang Peng.

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