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“Click” Synthesis of a Bipolar Dendrimer as a Host Material for Electrophosphorescent Devices |
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| Authors: | Jun Yang Tengling Ye Qing Zhang Dongge Ma |
| Institution: | 1. School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China;2. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China |
| 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%.  |
| Keywords: | click chemistry convergent orthogonal strategy dendrimers electrophosphorescence light‐emitting diodes |