Mechanisms of light emission from terbium ions (Tb3+) embedded in a Si rich silicon oxide matrix

Mechanisms of light emission in Tb doped Si rich SiOx matrix prepared by magnetron sputtering are studied by photoluminescence spectroscopy (PL). Characteristic PL peaks of Tb3+ ions and Si nanocrystals are simultaneously observed with an inverse relationship between their intensity. With a prolonged heat treatment at high temperatures, light emission from Tb3+ ions enhances at the expense of total quenching of the PL signal from the nanocrystals. It is suggested from the annealing studies as a function of process conditions and structural characterization that the light emission from Tb ions is mediated by trap states formed in the band gap of the oxide matrix by TbxSiyOz complexes or excess Si states.

► The effect of process parameters on light emission of Tb3+ is determined.
► Matrix effect on light emission mechanisms of Tb3+ is discussed.
► Silicate formation is found to favor PL from Tb3+.