Multicenters in Ce3+ visible emission of YAG ceramics

Abstract New aspects on the Ce3+ in YAG transparent ceramics, obtained from absorption and emission spectra in the 10–300 K range, under different visible excitation wavelengths, along with emission decays are presented. The spectra and lifetime of regular Ce Y 3 + center are similar to those reported for single crystals. In the attempt to reveal perturbed Ce3+ centers by defects, the 5d → 4f emission spectra under pulsed 532 nm (5 ns) excitation (below the Ce3+ absorption band) were recorded. The spectra and decays (at different wavelengths) are function on temperature, revealing at least three types of Ce3+ new emitting centers. The low temperature spectra, different from those of Ce Y 3 + center, are dominated by a set of strongly perturbed centers with very short lifetimes. At least two other types of perturbed centers were separated by using wavelength and temperature dependences of decays. The spectral characteristics of these perturbed Ce3+ centers by lattice defects are analyzed in terms of the effects of the structural changes induced by Ce3+ doping on the interaction with defects, by using recent reported results.