Measurement of photoluminescence efficiency of Ir(III) phenylpyridine derivatives in solution and solid-state films

We compared the photoluminescence efficiency (ΦPL) of fac-tris(2-phenylpyridine)iridium (Ir(ppy)3) and derivatives of it in solution and in doped solid-state films and estimated their radiative and nonradiative decay rates. The green phosphor of Ir(ppy)3 and blue phosphors of FIrpic, Ir(Fppy)3, FIr6 showed high ΦPL values approaching to 100% in both solution and doped solid-state films. On the other hand, the red phosphor of Btp2Ir(acac) showed lower ΦPL value less than 40% in both environments. Photoacoustic spectroscopy results indicated that for Btp2Ir(acac) nonradiative decay from the triplet state to the ground states is 64 ± 8%.