Monodisperse six-armed triazatruxenes: Microwave-enhanced synthesis and highly efficient pure-deep-blue electroluminescence

An effective strategy to achieve highly efficient pure-blue electroluminescence (EL) via a novel series of six-arm monodisperse macromolecules based on the triazatruxene and fluorene units were investigated. Luminescent monodisperse macromolecules with dendritic structures such as dendrimers and star-type oligomers were characterized by well-defined and dendritic structures as well as superior chemical purity. The resulting materials are less prone to aggregation in the solid state due to their hindered structures and emit pure blue light while the device efficiencies have been much improved. A family of monodisperse macromolecules with triazatruxene as a core and six oligofluorene arms as the branches has been designed. The maximum external quantum efficiency (EQE) and current efficiency achieved was 2.0% and 2.07 cd/A. Further optimization of the devices and investigation of the relationships between their chemical structures and optoelectronic properties are in progress.