Magnetic field dependence of triplet state in iridium complex phosphor

The magnetic field dependence of photo-luminescent spectrum in tris (2-phenylpyridine) iridium complex is reported. Upon applying magnetic field from 0 to 6 T, remarkable change of spectral band shape was observed at 4.2 K. Comparing the spectral variation under magnetic field with the time resolved spectra, it is clarified that the luminescence involves distinctive contributions from, at least, two spectral sets of zero-field-split triplet sub-levels, and an additional fast decay component which is presumably associated with the nearly singlet manifold. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)