Synthesis and electroluminescence of poly(aryleneethynylene)s based on fluorene containing holetransport units
2001; Royal Society of Chemistry; Volume: 11; Issue: 6 Linguagem: Inglês
10.1039/b100065i
ISSN1364-5501
AutoresXiaowei Zhan, Yunqi Liu, Gui Yu, Xia Wu, Daoben Zhu, Runguang Sun, Daike Wang, Arthur J. Epstein,
Tópico(s)Luminescence and Fluorescent Materials
ResumoA new series of light-emitting poly(aryleneethynylene)s (PAE) based on fluorene with sterically hindered substituents containing hole transport units such as tetraphenyldiaminobiphenyl, carbazole and thiophene and the non-planar unit binaphthyl were synthesized by a palladium-catalyzed coupling reaction. The introduction of hole transport moieties into the PAE main chain can improve the luminance properties of PAE type polymers. The electronic structures and photo- and electroluminescent (EL) properties of these polymers can be manipulated by simply varying the nature of the co-units in the polymeric chain. The spectral emission varies from greenish-blue to green or yellowish-green, depending on the composition of the copolymers. A single-layer light-emitting diode (LED) prepared from poly{[2,7-diethynyl-9,9-bis(2-ethylhexyl)fluorene]-alt-[N,N′-diphenyl-N,N′-bis(4-phenyl)-1,1′-biphenyl-4,4′-diamine]} (TPD-PFE) using an aluminium electrode emits green light (510 nm) with an EL external quantum efficiency of 0.007% and a brightness of 30 cd m−2 at a bias voltage of 27 V and a current density of 420 mA cm−2. An EL external quantum efficiency of 0.06% can be obtained from a blue-emitting double-layer LED with the structure of ITO/TPD-PFE/2-(2-hydroxyphenyl)pyridylberyllium/LiF/AlLi at a current density of 38 mA cm−2.
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