A Novel Fluorene‐Triphenylamine Hybrid That is a Highly Efficient Host Material for Blue‐, Green‐, and Red‐Light‐Emitting Electrophosphorescent Devices
A Novel Fluorene‐Triphenylamine Hybrid That is a Highly Efficient Host Material for Blue‐, Green‐, and Red‐Light‐Emitting Electrophosphorescent Devices
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DOI：
10.1002/adfm.200700191
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发表时间：
2007-11
影响因子：
19
通讯作者：
Ping-I Shih;Chen‐Han Chien;F.‐I. Wu;C. Shu
中科院分区：
文献类型：
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作者：
Ping-I Shih;Chen‐Han Chien;F.‐I. Wu;C. Shu
通过Friedel-Crafts-型取代反应合成了一种新型主体材料TFTPA（tris[4-（9-phenylfluorene-9-yl）phenyl]amine），该材料以三苯胺为核，以9-苯基-9-芴基为外围.由于其空间体积庞大的9-苯基-9-芴基基团的存在，TFTPA表现出高玻璃化转变温度（186 °C），并且在形态和电化学上稳定。此外，如原子力显微镜测量所示，三重态铱掺杂剂的聚集在TFTPA主体中显著减少，从而产生高效的全色磷光。基于TFTPA的器件的性能远远上级相应的基于mCP或CBP的器件，特别是在蓝色和红色发光电磷光器件系统中。基于FIrpic的蓝色发光器件的效率在100 cd m-2的实际亮度下达到12%（26 cd A-1）和18 lm W-1;基于Ir（piq）2acac的红色发光器件相对于基于CBP主体材料的参考器件表现出极低的开启电压（2.6 V）和三倍的器件效率增强（9.0 lm W-1）。
TFTPA (tris[4‐(9‐phenylfluoren‐9‐yl)phenyl]amine), a novel host material that contains a triphenylamine core and three 9‐phenyl‐9‐fluorenyl peripheries, was effectively synthesized through a Friedel‐Crafts‐type substitution reaction. Owing to the presence of its sterically bulky 9‐phenyl‐9‐fluorenyl groups, TFTPA exhibits a high glass transition temperature (186 °C) and is morphologically and electrochemically stable. In addition, as demonstrated from atomic force microscopy measurements, the aggregation of the triplet iridium dopant is significantly diminished in the TFTPA host, resulting in a highly efficient full‐color phosphorescence. The performance of TFTPA‐based devices is far superior to those of the corresponding mCP‐ or CBP‐based devices, particularly in blue‐ and red‐emitting electrophosphorescent device systems. The efficiency of the FIrpic‐based blue‐emitting device reached 12 % (26 cd A–1) and 18 lm W–1 at a practical brightness of 100 cd m–2; the Ir(piq)2acac‐based red‐emitting device exhibited an extremely low turn‐on voltage (2.6 V) and a threefold enhancement in device efficiency (9.0 lm W–1) relative to those of reference devices based on the CBP host material.