Nat. Commun.: 36% efficiency! High performance blue OLED

• Currently, organic light-emitting diodes (OLEDs) have been commercialized, using phosphors with 100% internal quantum efficiency (IQE) in green and red emission regions. Recently, Soo Young Park of Seoul University and Jongwook Park of Kei hee University reported three efficient multi resonance thermal activation delayed fluorescence blue emission host materials, including 5,9-dioxa-13b boron [3,2,1-de] cyclopentadienyl (DOBNA) and tetraphenylsilyl.

• Researchers use conventional N⁷，N⁷，N¹³，N¹³，5，9，11，15-octaphenyl5，9，11，15-tetrahydro-5，9，11，15-tetraaza-19b，20b-diboradinaphtho[3，2，1de:1’，2’，3’-jk]pentacene-7，13-diamine((4-(2，12-di-tert-butyl-5，9-dioxa-13b-boranaphtho[3，2，). The devices prepared with blue luminescent materials have high photoluminescence quantum yield greater than 0.82, horizontal orientation greater than 88%, and photoluminescence decay time ranging from 0.96 to 1.93 μ S
  

• Triphenylsilane (TDBA Si) exhibits a high external quantum efficiency of 36.2/35.0/31.3% at maximum brightness of 500 cd m − 2/1000 cd m − 2. This high performance is attributed to the rapid energy transfer from the main body to the dopant. Other factors that may lead to high performance include T1 excited state contribution, inhibition of aggregation by large volume tetraphenylsilyl groups, high horizontal orientation, and high thermal stability. Using TDBA-Si as the substrate material, a high efficiency of over 30% and a small roll drop of 4.9% were achieved on 1000 cd m − 2.
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• Park, D., Kang, S., Ryoo, C.H. et al. High-performance blue OLED using multiresonance thermally activated delayed fluorescence host materials containing silicon atoms. Nat Commun 14, 5589 (2023).

  https://doi.org/10.1038/s41467-023-41440-1