Simple and High Efficiency Phosphorescence Organic Light-Emitting Diodes with Codeposited Copper(I) Emitter

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• 作者：Zhiwei Liu ; Jacky Qiu ; Feng Wei ; Jianqiang Wang ; Xiaochen Liu ; Michael G. Helander ; Sarah Rodney ; Zhibin Wang ; Zuqiang Bian ; Zhenghong Lu ; Mark E. Thompson ; Chunhui Huang
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：April 8, 2014
• 年：2014
• 卷：26
• 期：7
• 页码：2368-2373
• 全文大小：370K
• 年卷期：v.26,no.7(April 8, 2014)
• ISSN：1520-5002

文摘

Phosphorescent copper(I) complexes show great promise as emitters in organic light-emitting diodes (OLEDs). However, most copper(I) complexes are neither soluble nor stable toward sublimation and, hence, not amenable to the typical methods to fabricate OLEDs. In this work, a compound 3-(carbazol-9-yl)-5-((3-carbazol-9-yl)phenyl)pyridine (CPPyC) was designed as both a good ligand and host matrix. Codeposition of CPPyC and copper iodide (CuI) gives luminescent films with photoluminescent quantum yields (PLQY) as high as 100%. A dimeric copper(I) complex Cu₂I₂(CPPyC)₄ is formed in the thin film, characterized by X-ray absorption spectroscopy. A series of simple, highly efficient green-emitting OLEDs were demonstrated by using the codeposited film as an emissive layer. A device comprised of only CPPyC and CuI gave an external quantum efficiency (EQE) of 12.6% (42.3 cd/A) at 100 cd/m², while a device with tailored hole and electron transporting layers gave an efficiency of 15.7% (51.6 cd/A) at the same brightness.