二苯并噻吩
有机发光二极管
电致发光
二苯并呋喃
荧光粉
氧化膦
咔唑
掺杂剂
材料科学
磷光
兴奋剂
光电子学
铱
氧化物
光化学
化学
磷化氢
物理
纳米技术
光学
有机化学
冶金
催化作用
硫黄
图层(电子)
荧光
作者
Linda S. Sapochak,Asanga B. Padmaperuma,P.A. Vecchi,Xiuyu Cai,P. E. Burrows
摘要
Phosphine oxide substitution of small molecules with high triplet exciton energies allows development of vacuum sublimable, electron transporting host materials for blue OLEDs. Heteroaromatic building blocks (carbazole, dibenzofuran and dibenzothiophene) with ET ~ 3 eV were incorporated into phosphine oxide (PO) structures. External quantum efficiencies (EQEs) at lighting brightness (i.e., 800 cd/m2) reached as high as 9.8% at 5.2V for OLEDs using the heteroaromatic PO hosts doped with the sky blue phosphor, iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2,) picolinate (FIrpic). Comparing device properties at a similar current density (i.e., J = 13 mA/cm2) showed the dibenzothiophene-bridged PO compound exhibits the highest EQEs and lowest operating voltages at all phosphor dopant levels. These results are explained with respect to the effects of the inductive phosphine oxide substituents on electrochemical, photophysical and electroluminescence properties of the substituted heteroaromatic building blocks.
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