中国物理B ›› 2012, Vol. 21 ›› Issue (10): 108507-108507.doi: 10.1088/1674-1056/21/10/108507
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
邵茗, 郭旭, 陈淑芬, 范曲立, 黄维
Shao Ming (邵茗), Guo Xu (郭旭), Chen Shu-Fen (陈淑芬), Fan Qu-Li (范曲立), Huang Wei (黄维)
摘要: 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).
中图分类号: (Light-emitting devices)