posted on 2024-02-02, 12:04authored byThéo Cavignac, Maxence Vigier, Emmanuel Fritsch, Philippe Deniard, Stéphane Jobic, Camille Latouche
Using jointly experimental results and first-principles
calculations,
we unambiguously assign the underlying mechanisms behind two commonly
observed luminescence bands for the Al2O3 material.
Indeed, we show that the red band is associated with a Ti3+d–d transition as expected,
while the blue band is the combination of the Ti3+ + O– → Ti4+ + O2– and
VO•+e– → VO× de-excitation processes. Thanks
to our recent developments, which take into account the vibrational
contributions to the electronic transitions in solids, we were able
to simulate the luminescence spectra for the different signatures.
The excellent agreement with the experiment demonstrates that it should
be possible to predict the color of the material with a CIE chromaticity
diagram. We also anticipated the luminescence signature of Al2O3:Ti,Ca and Al2O3:Ti,Be
that were confirmed by experiment.