Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 31, 2019
Previous Article Next Article

Dibenzo[b,d]furan and dibenzo[b,d]thiophene molecular dimers as hole blocking materials for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes

Author affiliations

Abstract

Novel hole blocking materials (HBMs) based on dibenzo[b,d]furan and dibenzo[b,d]thiophene molecular dimers have been rationally designed and synthesized for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes (PhOLEDs). Thermal, optical, and electrochemical analyses show that [2,2′-bidibenzo[b,d]furan]-6,6′-diylbis(diphenylphosphine oxide) (DBF-d-PO), [2,2′-bidibenzo[b,d]thiophene]-6,6′-diylbis(diphenylphosphine oxide) (DBT-d-PO), 6,6′-di(pyridine-3-yl)-2,2′-bidibenzo[b,d]furan (DBF-d-Py), and 6,6′-di(pyridine-3-yl)-2,2′-bidibenzo[b,d]thiophene (DBT-d-Py) possess high thermal stability, deep highest occupied molecular orbital energy levels (−6.61 to −6.95 eV), and high triplet energy (ET) (2.68–2.95 eV). Blue PhOLEDs with DBF-d-PO, DBT-d-PO, DBF-d-Py, and DBT-d-Py exhibit low turn-on and operating voltages, excellent external quantum efficiency, and high current and power efficiencies. A blue PhOLED with DBF-d-Py shows the best efficiency with a maximum external quantum efficiency of 24.3%, a maximum current efficiency of 44.3 cd A−1, and a maximum power efficiency of 46.4 lm W−1. In addition, it exhibits an outstanding external quantum efficiency of 22.4% at a practical luminance of 1000 cd m−2 and a very high maximum luminance of 88 953 cd m−2 at 12 V. Furthermore, blue PhOLEDs with DBF-d-Py and DBT-d-Py exhibit highly improved lifetimes compared with the conventional HBM, BmPyPB, because of the efficient hole blocking by the deep HOMO energy level and the high thermal stability stabilizing hole blocking layer morphology.

Graphical abstract: Dibenzo[b,d]furan and dibenzo[b,d]thiophene molecular dimers as hole blocking materials for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes

Back to tab navigation

Supplementary files

Article information


Submitted
21 May 2019
Accepted
12 Jul 2019
First published
15 Jul 2019

J. Mater. Chem. C, 2019,7, 9599-9608
Article type
Paper

Dibenzo[b,d]furan and dibenzo[b,d]thiophene molecular dimers as hole blocking materials for high-efficiency and long-lived blue phosphorescent organic light-emitting diodes

S. Jang, K. H. Lee, J. Y. Lee and Y. Lee, J. Mater. Chem. C, 2019, 7, 9599
DOI: 10.1039/C9TC02689D

Social activity

Search articles by author

Spotlight

Advertisements