Title :
Stable Binary Complementary White Light-Emitting Diodes Based on Quantum-Dot/Polymer-Bilayer Structures
Author :
Tan, Zhanao ; Hedrick, Brittany ; Zhang, Fan ; Zhu, Ting ; Xu, Jian ; Henderson, Ron H. ; Ruzyllo, Jerzy ; Wang, Andrew Y.
Author_Institution :
Dept. of Eng. Sci. & Mech., Pennsylvania State Univ., University Park, PA
Abstract :
A binary complementary white light-emitting diode (LED) was designed and fabricated by employing a colloidal quantum-dot (QD)/polymer-bilayer configuration in the device active region. Stable white electroluminescence is observed from the cumulative emission of the yellow-emitting CdSe-ZnS core-shell QDs and blue-emitting poly(N,N´-bis (4-butylphenyl)-N,N´-bis(phenyl)benzidine) (Poly-TPD) molecules. The white chromaticity of the LED output can be tailored by varying the respective thicknesses of the constituent emissive layers; whereas the emission color exhibits little dependence on the applied bias over a wide voltage range. The maximum luminance of the device reaches 2600 cd/m2 under a bias of 9.4 V.
Keywords :
II-VI semiconductors; cadmium compounds; colloids; light emitting diodes; organic light emitting diodes; semiconductor quantum dots; wide band gap semiconductors; zinc compounds; CdSe-ZnS; LED; blue-emitting poly(N,N´-bis (4-butylphenyl)-N,N´-bis(phenyl)benzidine); colloidal quantum-dot; poly-TPD; polymer-bilayer structure; quantum-dot structure; stable binary complementary white light-emitting diodes; stable white electroluminescence; voltage 9.4 V; yellow-emitting core-shell; Bilayer structure; quantum dots (QDs); white light-emitting diodes (LEDs);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2008.2006278
