Bright and Efficient Full-Color Colloidal Quantum Dot Light-Emitting Diodes Using an Inverted Device Structure

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• 作者：Jeonghun Kwak ; Wan Ki Bae ; Donggu Lee ; Insun Park ; Jaehoon Lim ; Myeongjin Park ; Hyunduck Cho ; Heeje Woo ; Do Y. Yoon ; Kookheon Char ; Seonghoon Lee ; Changhee Lee
• 刊名：Nano Letters
• 出版年：2012
• 出版时间：May 9, 2012
• 年：2012
• 卷：12
• 期：5
• 页码：2362-2366
• 全文大小：293K
• 年卷期：v.12,no.5(May 9, 2012)
• ISSN：1530-6992

文摘

We report highly bright and efficient inverted structure quantum dot (QD) based light-emitting diodes (QLEDs) by using solution-processed ZnO nanoparticles as the electron injection/transport layer and by optimizing energy levels with the organic hole transport layer. We have successfully demonstrated highly bright red, green, and blue QLEDs showing maximum luminances up to 23鈥?40, 218鈥?00, and 2250 cd/m², and external quantum efficiencies of 7.3, 5.8, and 1.7%, respectively. It is also noticeable that they showed turn-on voltages as low as the bandgap energy of each QD and long operational lifetime, mainly attributed to the direct exciton recombination within QDs through the inverted device structure. These results signify a remarkable progress in QLEDs and offer a practicable platform for the realization of QD-based full-color displays and lightings.

Keywords:

Quantum dots; quantum dot light-emitting diodes; inverted device structure; electroluminescence; zinc oxide nanoparticles