Energy transfer in a thin film of TPD fluorescent molecules doped with PtOEP and Ir(ppy)_3 phosphorescent molecules

摘要

A thin film of triphenylamine dimer, N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-benzidine (TPD), doped with fac tris(2-phenylpyridine) iridium (Ir(ppy)_3) and platinum octaethyl porphine (PtOEP) is characterized by pho-toluminescence emission measurements at several excitation wavelengths and photoluminescence excitation measurements at relevant emission wavelengths in the temperature range from 10 K to room temperature. The investigated film is a phosphorescent OLED material with singlet absorbing host (TPD) and triplet emitting guests [Ir(ppy)_3 and PtOEP]. At short wavelength excitation simultaneous triple band emission from singlet TPD, triplet Ir(ppy)_3 and TPD, and from triplet PtOEP is observed. Foerster-type singlet-singlet state energy transfer from TPD to Ir(ppy)_3 and PtOEP, intra-component intersystem crossing, and Dexter-type triplet-triplet energy transfer between the substituents are studied.