Efficient rare earth cerium(Ⅲ)complex with nanosecond d-femission for blue organic light-emitting diodes

• 来源期刊: 国家科学评论（英文版）
• 年，卷（期）: 2021,（2）
• 所属期刊栏目: RESEARCH ARTICLES
• 页码范围: 97-102
• 页数: 6页
• 语种: 英文
• DOI: 10.1093/nsr/nwaa193

摘要

In the field of RGB diodes,development of a blue organic light-emitting diode(OLED)is a challenge because of the lack of an emitter which simultaneously has a short excited state lifetime and a high theoretical external quantum efficiency(EQE).We demonstrate herein a blue emissive rare earth cerium(Ⅲ)complex Ce-2 showing a high photoluminescence quantum yield of 95％and a short excited state lifetime of 52.0 ns in doped film,which is considerably faster than that achieved in typical efficient phosphorescence or thermally activated delayed fluorescence emitters(typical lifetimes ＞ 1 μs).The corresponding OLED shows a maximum EQE up to 20.8％and a still high EQE of 18.2％at 1000 cd m-2,as well as an operation lifetime 70 times longer than that of a classic phosphorescence OLED.The excellent performance indicates that cerium(Ⅲ)complex could be a candidate for efficient and stable blue OLEDs because of its spin-and parity-allowed d-ftransition from the Ce3+ion.