Issue 26, 2024

Fine tuning the steric hindrance of the Eu(ii) tris(pyrazolyl)borate complex for a blue organic light-emitting diode

Abstract

Eu(II) complexes with characteristic d–f transitions demonstrate their potential applications in organic light-emitting diodes (OLEDs) due to their advantages including short excited-state lifetimes, 100% theoretical exciton utilization efficiency and tunable emission colors. Thermally stable and efficient Eu(II) complexes are necessary for blue OLEDs, which are still the bottleneck as compared to red and green OLEDs. A blue-emitting Eu(II) complex can be obtained by appropriate ligand design because the 5d energy levels are sensitive to the external environments. Herein, a series of Eu(II) complexes based on tris(pyrazolyl)borate ligands were designed and synthesized. By carefully adjusting the steric hindrance, a thermally stable sky-blue emission Eu(II) complex bis[hydrotris(3-tert-butylpyrazolyl)borate]europium(II) (Eu–tBu) was obtained by employing the bulky tert-butyl group. The sky-blue OLED based on Eu–tBu was fabricated, showing a maximum external quantum efficiency of 15.7%, a maximum luminance of 52 240 cd m−2, and Commission Internationale del Eclairage coordinates of (0.13, 0.27) at 1000 cd m−2.

Graphical abstract: Fine tuning the steric hindrance of the Eu(ii) tris(pyrazolyl)borate complex for a blue organic light-emitting diode

Supplementary files

Article information

Article type
Paper
Submitted
09 Mme 2024
Accepted
04 Jan 2024
First published
05 Jan 2024

J. Mater. Chem. C, 2024,12, 9834-9840

Fine tuning the steric hindrance of the Eu(II) tris(pyrazolyl)borate complex for a blue organic light-emitting diode

W. Yan, Y. Li, P. Huo, R. Guo, G. Yu, Z. Zhao, K. Wang, Z. Bian and Z. Liu, J. Mater. Chem. C, 2024, 12, 9834 DOI: 10.1039/D4TC01456A

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