Issue 27, 2024

Highly efficient and stable pure-red phosphorescent organic light-emitting diodes based on heptacyclic bipolar hosts featuring an armor-like structure

Abstract

Host material stability is essential to increase the lifetime for full-spectrum luminescence in efficient organic light-emitting diodes (OLEDs), especially red phosphorescent OLEDs (PhOLEDs). While the structural diversity of red emitters has developed rapidly in recent years, high-quality host materials are scarce and still rely heavily on traditional structures. Herein, a novel strategy is proposed by introducing heptacyclic heteroaromatics with an armor-like structure to design structurally non-traditional red hosts that are rigid enough to suppress conformational relaxation through reduced vibrations, thereby inhibiting non-radiative decay and improving stability. Accordingly, the red PhOLEDs based on the host named 2-([1,1′-biphenyl]-4-yl)-4-phenyl-1,3,5-triazine (Hept-TRZ) exhibit exceptional performance with a maximum current efficiency of 30.8 cd A−1 and the highest maximum external quantum efficiency (EQE) of 29.6% at 620 nm, as well as the high luminance of 65172 cd m−2. In particular, with satisfactory morphological stability and well-balanced hole and electron transport properties, the PhOLED device retains 95% of the luminance (LT95) even after 8777 hours of continuous operation at 1000 cd m−2, firmly establishing the negligible efficiency roll-off and superior stability with the new heptacyclic host. This work validates the superiority of this molecular design strategy and provides an instructive strategy for designing effective hosts for highly efficient and stable red PhOLEDs.

Graphical abstract: Highly efficient and stable pure-red phosphorescent organic light-emitting diodes based on heptacyclic bipolar hosts featuring an armor-like structure

Supplementary files

Article information

Article type
Paper
Submitted
01 abr 2024
Accepted
10 jun 2024
First published
11 jun 2024

J. Mater. Chem. C, 2024,12, 9993-9998

Highly efficient and stable pure-red phosphorescent organic light-emitting diodes based on heptacyclic bipolar hosts featuring an armor-like structure

Z. Meng, Y. Zhu, H. Li, X. Zhang, Y. Shang, C. Kuang and H. Meng, J. Mater. Chem. C, 2024, 12, 9993 DOI: 10.1039/D4TC01313A

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