Efficient top-emitting white organic light emitting device with an extremely stable chromaticity and viewing-angle |
| |
| Authors: | Shao Ming Guo Xu Chen Shu-Fen Fan Qu-Li Huang Wei |
| |
| Affiliation: | Key Laboratory Cultivation Base for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210046, China |
| |
| Abstract: | In this paper, we report on the fabrication of a top-emitting electrophosphorescent p-i-n white organic light-emitting diode on the basis of a low-reflectivity Sm/Ag semi-transparent cathode together with a thickness-optimized ZnS out-coupling layer. With a 24-nm out-coupling layer, the reflectivity of the cathode is reduced to 8% at 492 nm and the mean reflectivity is 24% in the visible area. By introducing an efficient electron blocking layer tris(1-phenylpyrazolato,N,C2')iridium(III) (Ir(ppz)3) to confine the exciton recombination area, the current efficiency and the colour stability of the device are effectively improved. A white emission with the Ir(ppz)3 layer exhibits a maximum current efficiency of 9.8 cd/A at 8 V, and the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates are almost constant during a large voltage change of 6 V-11 V. There is almost no viewing angular dependence in the spectrum when the viewing angle is no more than 45°, with a CIEx,y coordinate variation of only (±0.0025, ±0.0008). Even at a large viewing angle (75°), the CIEx,y coordinate change is as small as (±0.0087, ±0.0013). |
| |
| Keywords: | white organic light-emitting diode top-emitting electron blocking layer high efficiency colour stability |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《中国物理 B》浏览原始摘要信息 |
|
点击此处可从《中国物理 B》下载免费的PDF全文 |
|
