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Enhanced efficiency and reduced roll-off in white organic light-emitting diodes based on two ultra-thin emitting layers

Authors

  • Jianning Yu,

    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
    2. School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200072, P. R. China
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  • Hong Lin,

    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
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  • Liang Tong,

    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
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  • Chong Li,

    1. Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Wenyuan Road 9, Nanjing 210046, P. R. China
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  • Hao Zhang,

    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
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  • Jianhua Zhang,

    Corresponding author
    1. School of Mechatronic Engineering and Automation, Shanghai University, Shanghai 200072, P. R. China
    • Phone: +86 21 5633 4287, Fax: +86 21 5633 4287
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  • Zixing Wang,

    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
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  • Bin Wei

    Corresponding author
    1. Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Yanchang Road 149, Shanghai 200072, P. R. China
    • Phone: +86 21 5633 4331, Fax: +86 21 5633 4331
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Abstract

High efficiency performance and color rendering index (CRI) are two main requirements for the applications of white organic light-emitting diodes (WOLEDs). We report successful fabrication of efficient and high-color-rendering phosphorescent WOLED by employing ultra-thin red emitter – spacer layer – ultra-thin green emitter architecture. By fine-tuning the thicknesses of emitting layers and spacer layer, we have obtained WOLED with a high CRI of 80 and high luminance efficiency (LE) of 29.2 cd A−1 which only rolls off to 22.8 cd A−1 at 1000 cd m−2. A typical WOLED for comparison exhibits a CRI below 40 and maximum LE of 15.8 cd A−1 which decreases to 11.4 cd A−1 at 1000 cd m−2. The superiority of ultra-thin device compared with typical device demonstrates utilizing ultra-thin emitting layer is a promising technique to achieve high performance organic light-emitting diode (OLED).

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