Effects of silicon nanostructure evolution on Er³⁺ luminescence in silicon-rich silicon oxide/Er-doped silica multilayers

The effect of silicon nanostructure evolution on Er3+ luminescence is investigated by using multilayers of 2.5 nm thin Si Ox (x<2) and 10 nm thin Er-doped silica (Si O2: Er). By separating excess Si and Er atoms into separate, nanometer-thin layers, the effect of silicon nanostructure evolution on np-Si sensitized Er3+ luminescence could be investigated while keeping the microscopic Er3+ environment the same. The authors find that while the presence of np-Si is necessary for efficient sensitization, the overall quality of np-Si layer has little effect on the Er3+ luminescence. On the other hand, intrusion of np-Si into Er-doped silica layers leads to deactivation of np-Si Er3+ interaction, suggesting that there is a limit to excess Si and Er contents that can be used.