1. Deep blue light-emitting diodes based on Cd1?xZnxS@ZnS quantum dots.
- Author
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Wan Ki Bae, Jeonghun Kwak, Jaehoon Lim, Donggu Lee, Min Ki Nam, Kookheon Char, Changhee Lee, and Seonghoon Lee
- Subjects
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LIGHT emitting diodes , *QUANTUM dots , *CADMIUM-zinc alloys , *SEMICONDUCTOR doping , *BLUE light , *ORGANIC compounds , *ELECTROLUMINESCENT devices , *BANDWIDTHS - Abstract
We demonstrate deep blue light-emitting diodes based on chemically synthesized Cd1[?]xZnxS@ZnS quantum dots (QDs). Composite films of poly-(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (poly-TPD) and 4,4',N,N'-diphenylcarbazole (CBP) are employed for facilitated hole injection into Cd1[?]xZnxS@ZnS QDs and uniform QD deposition. The fabricated devices possess moderate turn-on voltage (6 V) and external quantum efficiency (0.1-0.3%), and exhibit color-saturated blue emission with a narrow spectral bandwidth of full width at half maximum <25 nm (Commission Internationale de l'Eclairage (CIE) coordinates of (0.169, 0.024) and (0.156, 0.028) for devices with electroluminescence (EL) lmax at 434 and 454 nm, respectively). Most of the emission originates from the Cd1[?]xZnxS@ZnS QD layers (99% of the total EL emission). [ABSTRACT FROM AUTHOR]
- Published
- 2009