Novel electron acceptor based on Spiro [fluorine-9,9′-xanthene] for exciplex thermally activated delayed fluorescence

作者：Cao, Hong-Tao; Zhao, Yu; Sun, Chen; Fang, Da; Xie, Ling-Hai^*; Yan, Min-Nan; Wei, Ying; Zhang, Hong-Mei^*; Huang, Wei^*

来源：Dyes and Pigments, 2018, 149: 422-429.

DOI：10.1016/j.dyepig.2017.10.019

• Spiro[fluorine-9,9 '-xanthene]
• Dicyano-substitution
• Thermally activated delayed fluorescence
• Exciplex
• Organic light-emitting diode
• Improved efficiencies

Two cyano-substituted spiro[fluorine-9,9'-xanthene] (SFX) derivatives, 2-carbonitrile-spiro[fluorene-9,9'-xanthene] (CNSFX) and 2,7-dicarbonitrile-spiro[fluorene-9,9'-xanthene] (DCNSFX) were conveniently prepared as electron acceptors to combine with tris(4-carbazoyl-9-ylphenyl)amine (TCTA) as electron donor to form exciplex emitters, respectively. Favorable exciplex-TADF was successfully achieved with photoluminescence quantum yield of 31% and electroluminescence efficiency of 8.2 cd A(-1) in TCTA:DCNSFX, which possesses increases of 1.1 and 3.3 times than those (15% and 1.9 cd A(-1)) of TCTA:CNSFX, respectively. The relatively favorable performance of TCTA:DCNSFX is related to the stronger electron-accepting ability through dicyano-substitution and larger driving force in the exciplex emission. These appealing results reveal that the dicyano-substituted SFX derivative opens interesting perspectives for developing favorable exciplex-TADF organic light-emitting diodes in the future.

• 出版日期2018-2
• 单位南京邮电大学; 西北工业大学