Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5399266 | Journal of Luminescence | 2015 | 22 Pages |
Abstract
In this work, we report the highly efficient pure blue electroluminescent (EL) device based on bis[(3,5-difluoro-4-cyanophenyl)pyridine]picolinate iridium(III) (FCNIrpic) doped 9-(4-tert-Butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi) film. The matched energy levels of FCNIrpic and CzSi are helpful in facilitating the trapping of carriers, while the high triplet energy of CzSi can well avoid the undesired reverse energy transfer. More importantly, the injection of holes was further accelerated by inserting 5Â nm 4,4â²,4â³-Tri(9-carbazoyl)triphenylamine (TcTa) film between hole transport layer and lighting-emitting layer (EML) as interlayer. Consequently, EL performances were significantly enhanced attributed to wider recombination zone and better balance of holes and electrons. Interestingly, single-EML device displayed higher performances than those of double-EMLs device. Finally, pure blue EL device with the structure of ITO/MoO3 (3Â nm)/TAPC (40Â nm)/TcTa (5Â nm)/FCNIrpic (20%): CzSi (30Â nm)/TmPyPB (40Â nm)/LiF (1Â nm)/Al (100Â nm) realized the maximum brightness, current efficiency, power efficiency and external quantum efficiency up to 12,505Â cd/m2, 36.20Â cd/A, 28.42Â lm/W and 16.9%, respectively. Even at the high brightness of 1000Â cd/m2, current efficiency and external quantum efficiency up to 17.40Â cd/A and 8.1%, respectively, can be retained by the same device.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Yunlong Jiang, Liang Zhou, Rongzhen Cui, Yanan Li, Xuesen Zhao, Hongjie Zhang,