Highly Efficient, Red Delayed Fluorescent Emitters with Exothermic Reverse Intersystem Crossing via Hot Excited Triplet States

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Ruifang Wang
  • Taiping Hu
  • Yanwei Liu
  • Xiaofang Wei
  • Jianjun Liu
  • Zhiyi Li
  • Xiaoxiao Hu
  • Honglei Gao
  • Guanhao Liu
  • Yukiko Yamada-Takamura
  • Pengfei Wang
  • Yuanping Yi
  • Ying Wang

Detail(s)

Original languageEnglish
Pages (from-to)20816-20826
Journal / PublicationJournal of Physical Chemistry C
Volume124
Issue number38
Online published31 Aug 2020
Publication statusPublished - 24 Sep 2020

Abstract

Three donor-Acceptor-donor molecular emitters have been designed by taking triphenylamine or N-phenylcarbazole as the donor and maleimide or phenyl maleimide as the acceptor, in which the highest occupied molecular orbital interaction between two donor units is maximized via the acceptor bridge. This is envisaged to enable both strong fluorescence radiation and fast exoergic reverse intersystem crossing via the second triplet state. Detailed photophysical characterization and theoretical calculations confirm that all the compounds have large oscillator strengths and short delayed fluorescence lifetimes of â 0.2 μs. The fabricated organic light-emitting diodes (OLEDs) give red emission above 600 nm, luminance exceeding 6000 cd m-2, and external quantum efficiencies (EQEs) of over 6%. In particular, the best device shows an emission at 645 nm and a maximum EQE of 10.4%. Moreover, the EQEs remain above 3% at 1000 cd m-2 for all the emitters. This work provides an effective method to develop organic emitters for highly efficient OLEDs with low-efficiency roll-off.

Research Area(s)

Citation Format(s)

Highly Efficient, Red Delayed Fluorescent Emitters with Exothermic Reverse Intersystem Crossing via Hot Excited Triplet States. / Wang, Ruifang; Hu, Taiping; Liu, Yanwei; Wei, Xiaofang; Liu, Jianjun; Li, Zhiyi; Hu, Xiaoxiao; Gao, Honglei; Liu, Guanhao; Yamada-Takamura, Yukiko; Lee, Chun-Sing; Wang, Pengfei; Yi, Yuanping; Wang, Ying.

In: Journal of Physical Chemistry C, Vol. 124, No. 38, 24.09.2020, p. 20816-20826.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review