Single dopant white electrophosphorescent light emitting diodes using heteroleptic tris-cyclometalated iridium(III) complexes

We report single dopant single emissive layer white organic electroluminescent (EL) device based on the heteroleptic tris-cyclometalated iridium(III) complex, Ir(dfppy)(2)(pq), as the guest, where dfppy and pq are 2-(2,4-difluorophenyl) pyridine and 2-phenylquinoline, respectively, and 1,4-phenylenesis(triphenylsilane) (UGH2) as the host. The maximum luminous and power efficiencies of the device were 11.00 cd/A (J=0.05 mA/cm(2)) and 5.60 lm/W (J=0.001 mA/cm(2)), respectively. The CIE coordinates of the device with Ir(dfppy)(2)(pq) are (0.443, 0.473) and the EL spectrum of device shows emission band at 473 and 544 nm, at the applied voltage of 12 V. The similar phosphorescent decay rate of two ligands can lead to emit luminescence in two ligands at the same time. (c) 2007 Elsevier B.V. All rights reserved.