Highly efficient phosphorescence from organic light-emitting devices with an exciton-block layer

• DOI: 10.1063/1.1385182
• Publication Date: 2002-07-26T14:18:02Z
• Authors: Masamichi Ikai; Shizuo Tokito; Youichi Sakamoto; Toshiyasu Suzuki; Yasunori Taga
• Keywords: Triphenylamine; Quantum Efficiency; Electrical efficiency

One of the keys to highly efficient phosphorescent emission in organic light-emitting devices is confine triplet excitons generated within emitting layer. We employ “starburst” perfluorinated phenylenes (C60F42) as a both hole- and exciton-block layer, hole-transport material 4,4′,4″-tri(N-carbazolyl) triphenylamine host for dopant dye A maximum external quantum efficiency reaches 19.2%, keeps over 15% even at high current densities 10–20 mA/cm2, providing several times brightness fluorescent tubes lighting. The onset voltage electroluminescence low 2.4 V peak power 70–72 lm/W, promising low-power display devices.