Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10714079 | Physica B: Condensed Matter | 2012 | 5 Pages |
Abstract
Non-doped white organic light-emitting devices (WOLEDs) with a quadruple-quantum-well structure were fabricated. An alternate layer of ultrathin blue and yellow iridium complexes was employed as the potential well layer, while potential barrier layers (PBLs) were chosen to be 2,2',2''-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) or N,N'-dicarbazolyl-3,5-benzene (mCP) combined TPBi. On adjusting the PBLs for device performance comparison, the results showed that the device with all-TPBi PBLs exhibited a yellow emission with the color coordinates of (0.50,0.47) at a luminance of 1000Â cd/m2, while stable white emission with the color coordinates of (0.36,0.44) was observed in the device using mCP combined TPBi as the PBLs. Meanwhile, for the WOLED, with a reduced efficiency roll-off, a maximum luminance, luminous efficiency, and external quantum efficiency of 12,610Â cd/m2, 10.2Â cd/A, and 4.4%, respectively, were achieved. The performance improvement by the introduction of mCP PBL was ascribed to the well confined exciton and the reduced exciton quenching effect in the multiple emission regions.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Juan Zhao, Junsheng Yu, Lei Zhang, Jun Wang,