A deep red phosphorescent Ir(III) complex for use in polymer light-emitting diodes: role of the arylsilyl substituents.

Here we report the synthesis and electrophosphorescence of a new deep-red phosphorescent Ir(III) complex with spatially embracing and thus solubilizing arylsilyl-substituted ligands, Ir(III) tris(2-(2'-benzo[b]thienyl)-5-(4'-triphenylsilylphenyl)pyridinato-N,C3'). A poly(N-vinylcarbazole) (PVK) film doped with this Ir(III) complex exhibited excellent phase homogeneity and showed saturated red electrophosphorescence of 2.7% maximum external quantum efficiency, whose Commission Internationale de L'Eclairage coordinates were (0.69, 0.30).