Luminescent properties of dysprosium(III) ions in LaAlO3 nanocrystallites

The absorption and emission spectra as well as decay time profile of Dy3+ ions in LaAlO3 nanocrystals were analyzed. The crystal structure of LaAlO3 was confirmed from XRD measurement. The emission peaks from blue to red came from main emitting level of dysprosium 4F9/2 to the ground and other excited levels of Dy3+ ions. Cross relaxation process led to non-radiative quenching of luminescence, so that the lifetime of the 4F9/2 energy level ions decreased with increasing amount of doped Dy3+ ions. The cross relaxation transfer rates were experimentally determined as a function of Dy3+ concentration.