Published online by Cambridge University Press: 15 March 2011
We have fabricated phosphorescent light emitting devices using mixed ligand bisorthometalated Ir(III) complexes, chlorobis-(2-phenylpyridinato-N,C 2 ')pyridineiridium(III) [Ir(Cl)(ppy)2(py)] and chlorobis-(2-phenylpyridinato-N,C 2')triphenylphosphine iridium(III) [Ir(Cl)(ppy)2P(Ph)3] chlorobis-(2-phenylpyridinato-N,C 2')tri-n-butylphosphine iridium(III) [Ir(Cl)(ppy)2P(n-Bu)3], where ppy is the orthometalating ligand. These complexes vary in their HOMO (highest occupied molecular orbital), LUMO (lowest unoccupied molecular orbital) and emissive states in accordance with the φ-accepting abilities of the non-orthometalating ligands. The lifetimes and EL spectrum of the devices were studied and compared.