Sensitization of erbium in silicon oxide by evaporation and thermal oxidation

We report on the room temperature photoluminescence (PL) at 1.54 μm from erbium-doped silicon rich silicon oxide (ErSRSO) films, fabricated on fused quartz by thermal evaporation followed by thermal-annealing in air. PL measurements show maximum intensity in samples annealed at 1000°C for four hours. X-ray diffraction (XRD) structural analyses show that annealing caused the formation of active Er3+ (Er2O3) centers. XRD and PL results show that increasing Er2O3 concentration does not necessarily lead to an increase in photoluminescence. Compositional analysis using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) depth-profiling shows a strong correlation between the presence of contiguous Si rich regions and Er2O3 centers on the one hand and the observed PL on the other. The combination of PL, XRD, and TOF-SIMS results indicate the presence of silicon nanoclusters and its sensitization of erbium.