Issue 42, 2023

Extending rigid electron-deficient skeletons and appending electron-rich units to build high-efficiency red-emitting pyrene-derived TADF materials

Abstract

In order to develop novel pyrene-derived thermally activated delayed fluorescence (TADF) materials and deeply study their structure–property relationship, two emitters of PyPzCN-TPA2 and PyQlCN-TPA2 were designed and synthesized by alternating dicyano pyrenopyrazine (PyPzCN) and dicyano pyrenoquinoxaline (PyQlCN) as the rigid electron-deficient skeleton, as well as triphenylamine (TPA) as an electron-rich unit anchored at the K-region of pyrene, respectively. The effects of the rigid electron-deficient skeleton and electron-rich unit on photophysical and electroluminescence (EL) properties were primarily studied. The extending rigid electron-deficient skeleton made PyQlCN-TPA2 exhibit red-shifted emission at 658 nm in toluene and 840 nm in its neat film. The appending electron-rich unit at the K-region made both emitters exhibit large steric hindrance with a torsion angle of more than 70°, which resulted in a small ΔEST value of about 0.032 eV and a high kRISC of about 1.6–4.7 × 105 s−1. As a result, the solution-processed PyPzCN-TPA2 and PyQlCN-TPA2-doped OLEDs simultaneously exhibited high EQEs of 9.30% at 588 nm and 8.94% at 630 nm, respectively. The EQE roll-off was efficiently suppressed with an increase of emission wavelength. This is the first time that high-efficiency red-emitting pyrene-derived TADF materials were obtained by extending the rigid electron-deficient skeleton and appending the electron-rich unit at the K-region for solution-processed OLEDs.

Graphical abstract: Extending rigid electron-deficient skeletons and appending electron-rich units to build high-efficiency red-emitting pyrene-derived TADF materials

Supplementary files

Article information

Article type
Paper
Submitted
17 Sep 2023
Accepted
07 Oct 2023
First published
10 Oct 2023

J. Mater. Chem. C, 2023,11, 14876-14883

Extending rigid electron-deficient skeletons and appending electron-rich units to build high-efficiency red-emitting pyrene-derived TADF materials

X. Chang, K. Lu, K. Jiang, B. Ma, J. Huang, X. Gan, Y. Liu, J. Yu and W. Zhu, J. Mater. Chem. C, 2023, 11, 14876 DOI: 10.1039/D3TC03390B

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