Luminescence from V3+ in tetrahedral oxo-coordination

Luminescence from trivalent vanadium in tetrahedral oxo-coordination is observed in LiGaO2, LiAlO2, and SrAl2O4. In LiGaO2 the V3+ ion exhibits the most intense broad-band emission between 1400 and 2000 nm with lifetimes of 89 and 11 μs at 12 and 300 K, respectively. The decrease in the lifetime is mainly caused by non-radiative decay processes, the quantum efficiency at room temperature is about 2.5%. In LiAlO2 and SrAl2O4 the non-radiative quenching process is even stronger because of the smaller energy gap between the participating levels and the larger electron–phonon coupling. In all crystals, even at low temperature, significant non-radiative decay occurs.