Orange luminescence of α-AlO related to clusters consisting of F centers and divalent cations.

The orange luminescence of α-AlO under UV excitation is characterized by a 2.07-eV orange broadband emission that has not yet been elucidated. This emission is present in natural and synthetic crystals and powders, as well as in Be-treated samples.

Luminescence Properties of AlO:Ti in the Blue and Red Regions: A Combined Theoretical and Experimental Study.

Using jointly experimental results and first-principles calculations, we unambiguously assign the underlying mechanisms behind two commonly observed luminescence bands for the AlO material. Indeed, we show that the red band is associated with a Ti - transition as expected, while the blue band is the combination of the Ti + O → Ti + O and V+ → V 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.