Synthesis and properties of copolymers based on dialkylfluorene and 3,6-fluorene substituted by triphenylamine units

A series of conjugated copolymers derived from 9,9-dioctyl-2,7-fluorene (DOF). and 9,9-bis (4-diphenylaminophenyl)-3,6-fluorene(36FT) were prepared by Suzuki coupling polymerization, which have a high molecular weights(M(n) =47000-189000). The resulting copolymers are readily soluble in common organic solvents such as THF, CHCl(3) and toluene etc.. The electrochemical, optical and electroluminescent properties were investigated. Cyclic voltammogram. (CV) indicates that the HOMO level of the copolymers is higher than that of the PF homopolymer, and it increases with the increase in 36FT mass fraction from 2% to 35%. The blue polymer light-emitting diodes(PLEDs) with the device configuration of ITO/PEDOT/PVK/polymer/Ba/Al were prepared. The highest external quantum efficiency was 0.52% from the device with 36PFT10 as the active layer.