“Click” Synthesis of a Bipolar Dendrimer as a Host Material for Electrophosphorescent Devices

✍ Scribed by Jun Yang; Tengling Ye; Qing Zhang; Dongge Ma

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 286 KB
• Volume: 211
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.201000197

✦ Synopsis

Abstract

A new solution‐processable bipolar dendrimer with carbazole units as hole‐transporting units and oxadiazole units as electron‐transporting units was efficiently synthesized based on a convergent approach by alternation of a Cu‐catalyzed azide/alkyne cycloaddition reaction and Williamson ether synthesis. The orthogonal chemistry completely avoided protection and activation of the focal points in the process of dendrimer synthesis. The dendrimer showed a wide bandgap and good thermal stability. Electrophosphorescent devices with the configuration ITO/PEDOT:PSS/bipolar dendrimer:Ir(ppy)~3~/TPBI/LiF/Al were fabricated. The devices showed a maximum current efficiency of 16.8 cd · A^−1^, a maximum power efficiency of 4.22 lm · W^−1^ and an external quantum efficiency of 5.7%.

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