High-efficiency phosphorescent polymer light-emitting devices

• DOI: 10.1016/j.orgel.2003.08.005
• Publication Date: 2003-09-17T00:11:16Z
• Authors: Shizuo Tokito; Mitsunori Suzuki; Fumio Sato; Motoaki Kamachi; Kourou Shirane
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

In this paper, we describe the performance of polymer light-emitting devices (PLEDs) that are based on phosphorescent polymers involving a carbazole unit and an iridium-complex unit. The PLEDs exhibit red, green or blue emission, depending on the phosphorescent polymer used in the emissive layer. We achieved highly external quantum efficiencies of 5.5%, 9% and 3.5% in respective red, green and blue PLEDs by selecting the electron transport material for the emissive layer and optimizing the content of the iridium-complex unit in the phosphorescent polymer chain. Furthermore, we demonstrated white emission in PLEDs by using blue-phosphorescent and red-phosphorescent polymers. An external quantum efficiency of 4.5% was obtained for this emission.