Efficient white organic light-emitting device based on a thin layer of hole-transporting host with rubrene dopant
Document Type
Article
Publication Date
12-1-2005
Abstract
A white organic light-emitting device (WOLED) in which a yellow fluorescent dye, rubrene (5,6,11,12-tetraphenylnaphthacene), is doped into a thin layer of traditional hole-transporting material NPB {4,4′-bis[N-(1-naphthyl)-N- phenylamino]biphenyl} is fabricated. The device has a simple structure of indium tin oxide (ITO)/CuPc/NPB/NPB: 0.7 wt.% rubrene/TPBI/lithium fluoride (LiF)/Al, where CuPc (copper phthalocyanine) and TPBI {2,2′,2″-(1,3,5- benzenetriyl)tris[1-phenyl-1H-benzimidazole]} are used as the hole-injecting layer and electron-transporting and hole-blocking layer, respectively. The device exhibits peak efficiency of 3.7 cd/A (2.1 lm/W) at 5.5 V and maximum brightness of 8200 cd/m2 at 20 V. The Commission Internationale de l'Eclairage (CIE) coordinates of (0.291, 0.303) are determined at 6 V. When the bias increased from 6 V to 14 V, the colour coordinates shifted only by ∼2%, which is presumably related closely to the thickness of the doped NPB layer. Besides, the electroluminescent (EL) efficiency can also be improved by decreasing the thickness of the doped NPB layer. The mechanisms of generating stable white colour and improving EL performances are also discussed. © 2005 Elsevier Ltd. All rights reserved.
Publication Source (Journal or Book title)
Solid-State Electronics
First Page
1956
Last Page
1960
Recommended Citation
Li, M., Li, W., Niu, J., Chu, B., Li, B., Sun, X., Zhang, Z., & Hu, Z. (2005). Efficient white organic light-emitting device based on a thin layer of hole-transporting host with rubrene dopant. Solid-State Electronics, 49 (12), 1956-1960. https://doi.org/10.1016/j.sse.2005.08.011