Concentration quenching of the luminescence from trivalent thulium, terbium, and erbium ions embedded in an AlN matrix

The concentration quenching behaviour of erbium, terbium, and thulium ions embedded in sputter deposited AlN films was investigated. For each of these three systems a series of specimens with different ion concentrations was prepared. In all three cases the concentration for maximum of the luminescence intensity (optimum concentration) at the selected excitation parameters was determined. These optimum concentrations differ strongly for the different ions. A rate equation model based on transition probabilities can explain the observations.