Solution-Processable High Efficiency Yellow Electroluminescent Device Based On Cationic Iridium Complex

A highly luminescent cationic iridium(III) complex with formula [Ir(Meppy)(2)(pybmzht)](+)(PF6)(-) was synthesized and characterized (where Meppy is 2-(4-methylphenyl)pyridine; pybmzht is 2,2-dimethy1-6-(2-(pyridin-2-y1)-1H- benzo [d]imidazol-1-yphexanenitrile). [Ir(Meppy)(2) (pybmzht)](+) (PF6)(-) exhibited yellow-emitting with PL peaked at 580 nm in solution. The no-doped electroluminescent device with the configuration; of ITO/PEDOT:PSS/complex/TPBI/CsF/A1 showed excellent properties with a luminous efficiency of 11 cd/A and an external quantum efficiency of 4.2%. High brightness of 12200 cd/m(2) and low turn on voltage of 4.3 V were realized while the host materials are absent. The results indicate that cationic iridium complexes are promising candidates in the high-efficiency no-doped electroluminescent device.