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Sequential Multiple Borylation Toward an Ultrapure Green Thermally Activated Delayed Fluorescence Material.

Shigetada UemuraSusumu OdaMasahiro HayakawaRyosuke KawasumiNaoya IkedaYi-Ting LeeChin-Yiu ChanYouichi TsuchiyaChihaya AdachiTakuji Hatakeyama
Published in: Journal of the American Chemical Society (2022)
Multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters have emerged as an important component of organic light-emitting diodes (OLEDs) because of their narrowband emission and high exciton utilization efficiency. However, the chemical space of MR-TADF emitters remains mostly unexplored because of the lack of suitable synthetic protocols. Herein, we demonstrate a sequential multiple borylation reaction that provides new synthetically accessible chemical space. ω-DABNA , the proof-of-concept material, exhibited narrowband green TADF with a full width at half-maximum of 22 nm and a small singlet-triplet energy gap of 13 meV. The OLED employing it as an emitter exhibited electroluminescence at 512 nm, with Commission International de l'Éclairage coordinates of (0.13, 0.73) and a high external quantum efficiency (EQE) of 31.1%. Moreover, the device showed minimum efficiency roll-off, with an EQE of 29.4% at 1000 cd m -2 .
Keyphrases
  • energy transfer
  • light emitting
  • quantum dots
  • photodynamic therapy
  • single molecule
  • contrast enhanced
  • molecular dynamics