Synthesis and electroluminescence of poly(aryleneethynylene)s based on fluorene containing hole-transport units

Citation
Xw. Zhan et al., Synthesis and electroluminescence of poly(aryleneethynylene)s based on fluorene containing hole-transport units, J MAT CHEM, 11(6), 2001, pp. 1606-1611
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS CHEMISTRY
ISSN journal
0959-9428 → ACNP
Volume
11
Issue
6
Year of publication
2001
Pages
1606 - 1611
Database
ISI
SICI code
0959-9428(2001)11:6<1606:SAEOPB>2.0.ZU;2-X
Abstract
A new series of light-emitting poly(aryleneethynylene)s (PAE) based on fluo rene with sterically hindered substituents containing hole transport units such as tetraphenyldiaminobiphenyl, carbazole and thiophene and the non-pla nar unit binaphthyl were synthesized by a palladium-catalyzed coupling reac tion. The introduction of hole transport moieties into the PAE main chain c an improve the luminance properties of PAE type polymers. The electronic st ructures and photo- and electroluminescent (EL) properties of these polymer s can be manipulated by simply varying the nature of the co-units in the po lymeric chain. The spectral emission varies from greenish-blue to green or yellowish-green, depending on the composition of the copolymers. A single-l ayer 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 3 0 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-em itting double-layer LED with the structure of ITO/TPD-PFE/2-(2-hydroxypheny l)pyridylberyllium/LiF/AlLi at a current density of 38 mA cm(-2).