Bistriazoles with a Biphenyl Core Derivative as an Electron-Favorable Bipolar Host of Efficient Blue Phosphorescent Organic Light-Emitting Diodes

High-quality host materials are indispensable for the construction in the emitting layer of efficient organic light-emitting diodes (OLEDs), especially in a guest and host system. The good carrier transport and energy transfer between the host and emitters are out of necessity. In this work, a wide...

Full description

Saved in:
Bibliographic Details
Published in:ACS applied materials & interfaces 2020-11, Vol.12 (44), p.49895-49904
Main Authors: Lee, Jiun-Haw, Chen, Chia-Hsun, Lin, Bo-Yen, Lan, Yi-Hsin, Huang, Yi-Mei, Chen, Nai-Jing, Huang, Jau-Jiun, Volyniuk, Dmytro, Keruckiene, Rasa, Grazulevicius, Juozas Vidas, Wu, Yuh-Renn, Leung, Man-kit, Chiu, Tien-Lung
Format: Article
Language:English
Subjects:
Organic Electronic Devices
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:High-quality host materials are indispensable for the construction in the emitting layer of efficient organic light-emitting diodes (OLEDs), especially in a guest and host system. The good carrier transport and energy transfer between the host and emitters are out of necessity. In this work, a wide bandgap and bipolar organic compound, 2,2′-bis­(4,5-diphenyl-(1,2,4)-triazol-3-yl)­biphenyl (BTBP), conjugating two electron-transporting triazole moieties on a hole-transporting biphenyl core, was synthesized and characterized. The wide bandgap of 4.0 eV makes the promise in efficient energy transfer between the host and various color emitters to apply as the universal host, especially for blue emitters. The close electron and hole mobilities perform the same order of 10–5 cm2·V–1·s–1, identified as bipolar behavior and benefited for carrier balance at low bias. Although carrier transportation belongs to bipolar behavior at a low electrical field, the electron mobility is much faster than the hole one at a high electrical field and belongs to electron-transporting behavior. Employing the BTBP as the host matrix mixed with a phosphor dopant, iridium­(III)­bis­[4,6-di-fluorophenyl-pyridinato-N,C2]­picolinate, a high-efficiency sky-blue phosphorescent organic light-emitting diode (OLED) was achieved with a maximum current efficiency of 65.9 cd/A, maximum power efficiency of 62.8 lm/W, and maximum external quantum efficiency of 30.2%.
ISSN:1944-8244
1944-8252
DOI:10.1021/acsami.0c13705