Issue 8, 2021

An unsymmetrical thermally activated delayed fluorescence emitter enables orange-red electroluminescence with 31.7% external quantum efficiency

Abstract

The thermally activated delayed fluorescence (TADF) emitters based on donor–acceptor (D–A) configuration were continuously developed in the past few years, whereas an unsymmetrical TADF emitter with A–D–A′ configuration has never been reported. Herein, an A–D–A′ type TADF emitter of TRZ–SBA–NAI was firstly developed by simultaneously integrating 2-phenyl-1H-benzo[de]isoquinoline-1,3(2H)-dione and 2,4,6-triphenyl-1,3,5-triazine acceptors into a spirobiacridine donor core. Due to the coexistence of double charge-transfer excited states, TRZ–SBA–NAI displayed dual emission containing a dominant orange-red emission and an anti-Kasha's rule sky-blue emission shoulder in solution. As doped into the host matrix, TRZ–SBA–NAI only exhibited an orange-red emission, together with a high photoluminescence quantum yield of 87%. The linear molecular shape imparted TRZ–SBA–NAI with a high horizontal dipole ratio of 88%. As a result, the TRZ–SBA–NAI based devices achieved a record-high external quantum efficiency of 31.7% with an electroluminescence peak at 593 nm. This finding not only enriches the diversity in TADF molecular design, but also unlocks the huge potential of A–D–A′ type TADF emitters for excellent device performance.

Graphical abstract: An unsymmetrical thermally activated delayed fluorescence emitter enables orange-red electroluminescence with 31.7% external quantum efficiency

Supplementary files

Article information

Article type
Communication
Submitted
14 Apr 2021
Accepted
09 Jun 2021
First published
09 Jun 2021

Mater. Horiz., 2021,8, 2286-2292

An unsymmetrical thermally activated delayed fluorescence emitter enables orange-red electroluminescence with 31.7% external quantum efficiency

X. Zeng, Y. Huang, S. Gong, P. Li, W. Lee, X. Xiao, Y. Zhang, C. Zhong, C. Wu and C. Yang, Mater. Horiz., 2021, 8, 2286 DOI: 10.1039/D1MH00613D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements