| Autor: |
Zhang, Dongyu, Li, Wenlian, Chu, Bei, Zhu, Jianzhuo, Li, Tianle, Han, Lianglaing, Bi, Defeng, Li, Xiao, Yang, Dongfang, Yan, Fei, Liu, Huihui, Wang, Dan, Tsuboi, Taiju |
| Předmět: |
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| Zdroj: |
Applied Physics Letters; 10/29/2007, Vol. 91 Issue 18, p183516, 3p, 1 Diagram, 2 Graphs |
| Abstrakt: |
We demonstrate a fac-tris(2-phenylpyridine) iridium-based electrophosphorescent organic green-light emitting diode with a considerably reduced current-efficiency roll off at high current density. Such a low roll off of efficiency was achieved by inserting nondoped 4,4′-N,N′-dicarbazole-biphenyl (CBP) layer and a tris-(8-hydroxy-quinoline) aluminum (Alq3) layer between the emitting and electron-transporting layers to diffuse excitons from the emitting layer. The Alq3 layer is found to contribute as a complementary green fluorescent emitter at high current density. Thus, only a small decrease from 20.7 to 16.7 cd/A was detected in current efficiency when the current density increases from 3.9 to 100 mA/cm2. A high current efficiency of 12.6 cd/A was achieved even at 350 mA/cm2, indicating that the efficiency roll off was drastically reduced when compared with the device without CBP and Alq3 layers. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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