Premium
m ‐Indolocarbazole Derivative as a Universal Host Material for RGB and White Phosphorescent OLEDs
Author(s) -
Lai ChengChang,
Huang MinJie,
Chou HoHsiu,
Liao ChuangYi,
Rajamalli Pachaiyappan,
Cheng ChienHong
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201502079
Subject(s) - phosphorescence , materials science , oled , phosphor , electroluminescence , optoelectronics , dopant , quantum efficiency , diode , phosphorescent organic light emitting diode , carbazole , doping , layer (electronics) , photochemistry , nanotechnology , optics , chemistry , physics , fluorescence
The host materials designed for highly efficient white phosphorescent organic light‐emitting diodes (PhOLEDs) with power efficiency (PE) >50 lm W ‐1 and low efficiency roll‐off are very rare. In this work, three new indolocarbazole‐based materials (ICDP, 4ICPPy, and 4ICDPy) are presented composed of 6,7‐dimethylindolo[3,2‐ a ]carbazole and phenyl or 4‐pyridyl group for hosting blue, green, and red phosphors. Among this three host materials, 4ICDPy‐based devices reveal the best electroluminescent performance with maximum external quantum efficiencies (EQEs) of 22.1%, 27.0%, and 25.3% for blue (FIrpic), green ( fac ‐Ir(ppy) 3 ), and red ((piq) 2 Ir(acac)) PhOLEDs. A two‐color and single‐emitting‐layer white organic light‐emitting diode hosted by 4ICDPy with FIrpic and Ir(pq) 3 as dopants achieves high EQE of 20.3% and PE of 50.9 lm W −1 with good color stability; this performance is among the best for a single‐emitting‐layer white PhOLEDs. All 4ICDPy‐based devices show low efficiency roll‐off probably due to the excellent balanced carrier transport arisen from the bipolar character of 4ICDPy.