Decay dynamics of photo-luminescence in tris(2-phenylpyridine)iridium phosphor

The phosphor material, tris(2-phenylpyridine)iridium (Ir(ppy)3), has attracted much attention as an emitter of highly efficient electro-phosphorescent devices. In the present work, decay dynamics of photo-luminescence and its temperature dependence have been investigated in the Ir(ppy)3 emitting center. From the analyses of luminescent decay profiles and time-resolved luminescent spectra, thermally activated population transfer from every triplet sub-level to a singlet state is suggested.