Tb3+ Luminescence in a-SiNx:H

Abstract

Terbium doped hydrogenated amorphous silicon nitride was prepared by reactive RF-sputtering from a silicon target partially covered either with Tb4O7 or metallic Tb platelets in a Ar+N2+H2 atmosphere. When the samples have a high enough bandgap they present characteristic Tb3+ luminescence. The luminescence intensity depends on the annealing temperature. For a given smaple, the luminescence intensity under non-resonant excitation is 10 to 20 times smaller than under resonant excitation of Tb3+. The luminescence intensity under resonant excitation slightly increases with temperature, while under non-resonant excitation it decreases with temperature.. These results are interpreted as due to very effective intra-4f radiative recombination processes in Tb3+ in a-SiNx:H. However, the excitation transfer from the matrix is inefficient or our samples are not yet fully optimized for it.