1. High-Efficient Deep-Blue Light-Emitting Diodes by Using High Quality Zn xCd1- xS/ZnS Core/Shell Quantum Dots.
- Author
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Shen, Huaibin, Bai, Xianwei, Wang, Aqiang, Wang, Hongzhe, Qian, Lei, Yang, Yixing, Titov, Alexandre, Hyvonen, Jake, Zheng, Ying, and Li, Lin Song
- Subjects
LIGHT emitting diodes ,QUANTUM dots ,ELECTROLUMINESCENCE ,BLUE light ,ZINC sulfide - Abstract
High-quality violet-blue emitting Zn
x Cd1- x S/ZnS core/shell quantum dots (QDs) are synthesized by a new method, called 'nucleation at low temperature/shell growth at high temperature'. The resulting nearly monodisperse Znx Cd1- x S/ZnS core/shell QDs have high PL quantum yield (near to 100%), high color purity (FWHM) <25 nm), good color tunability in the violet-blue optical window from 400 to 470 nm, and good chemical/photochemical stability. More importantly, the new well-established protocols are easy to apply to large-scale synthesis; around 37 g Znx Cd1- x S/ZnS core/shell QDs can be easily synthesized in one batch reaction. Highly efficient deep-blue quantum dot-based light-emitting diodes (QD-LEDs) are demonstrated by employing the Znx Cd1- x S/ZnS core/shell QDs as emitters. The bright and efficient QD-LEDs show a maximum luminance up to 4100 cd m−2 , and peak external quantum efficiency (EQE) of 3.8%, corresponding to 1.13 cd A−1 in luminous efficiency. Such high value of the peak EQE can be comparable with OLED technology. These results signify a remarkable progress, not only in the synthesis of high-quality QDs but also in QD-LEDs that offer a practicle platform for the realization of QD-based violet-blue display and lighting. [ABSTRACT FROM AUTHOR]- Published
- 2014
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