Extending the nanocluster-Si/erbium sensitization distance in Er-doped silicon nitride: The role of Er-Er energy migration

Abstract

The nanocluster-Si (nc-Si)/Er(3+) interaction distance in Er-doped silicon nitride is investigated using SiO(x)/Si(3)N(4):Er/Si(3)N(4)/Si(3)N(4):Er multilayers. The composition and thickness of SiO(x) layers were fixed to provide constant sensitization, while the thickness of Si(3)N(4):Er layers was varied to probe distance-dependence of sensitization. We find that while the distance over which an nc-Si transfers energy to an Er(3+) ion is constant at similar to 0.3 nm, the effective sensitization distance over which an Er(3+) is sensitized via nc-Si can be as large as similar to 1.3 nm. Based on a widely used phenomenological model of the distance-dependent Er(3+) photoluminescence intensity, we identify Er-Er energy migration as an important factor for the extension of the nc-Si sensitization distance over nc-Si energy transfer distance.