Synthesis and light-emitting properties of fluorene-based copolymers Bearing Diphenyl imidazole Chromophore
writer：Qiang Peng*, Guanwen Fu, Dan Su.
keywords：polymer light-emitting diodes
source：期刊
specific source：Synthetic Metals,2010,160,1672-1678.
Issue time：2010年
New type of alternating fluorene-based copolymers containing electron-deficient aryl-substituted imidazole units in the main chains were designed, synthesized and characterized. The resulting copolymers were amorphous and showed excellent solubility in common organic solvents, such as dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, toluene, and THF. These polymers also possessed good thermal stability with glass transition temperatures of 96 and 82 oC and decomposition onset temperatures of 365 and 379 oC, respectively. They exhibited good blue photoluminescence properties with high photoluminescence efficiencies. The long-wavelength emission of polyfluorenes had been effectively reduced by introduction of nonlinear structure aryl-substituted imidazole units. Light-emitting devices with an ITO/PEDOT/PVK/copolymer/LiF/Al configuration could emit strong blue light with high external quantum efficiencies of 1.49 and 2.05%.