Polymer phosphorescent light-emitting devices doped with tris(2-phenylpyridine) iridium as a triplet emitter

We have fabricated phosphorescent polymer light-emitting devices with tris( 2-phenylpyridine) iridium [Ir(ppy)(3)] as a triplet emissive dopant in poly (vinylcarbazole) (PVK) host. The device with 8% doping concentration of [Ir (ppy)(3)] in PVK showed the external quantum efficiency of 1.9% and the pea k luminance of 2,500 cd/m(2). The emission spectrum of the device exhibited no emission from PVK, indicating that the energy transfer from PVK to [Ir( ppy)(3)] is efficient. This work demonstrates that efficient electrophospho rescent light-emitting devices can be realized with polymers. (C) 2000 Amer ican Institute of Physics. [S0003-6951(00)00141-8].