We have studied photoluminescence (PL) from samples of Er-doped Si-rich silicon oxide (SRSO) annealed at for in , (FG1), (FG2), and , respectively, or subjected to double-step annealing processes. For the given film composition, the PL spectra of the samples annealed in , FG1, or FG2 are similar in shape but reveal small differences in the intensities of emission bands; while the spectra are qualitatively different in the case of oxidation. By combining the treatments of oxidation and annealing in FG1, the PL intensity of the SRSO matrix increases significantly; the emission from Si nanoclusters (Si-ncls) is also enhanced while the PL remains efficient. The effects of annealing gas ambients are discussed in terms of hydrogen passivation, Si oxynitridation and/or oxidation occurring in the film upon annealing and play different roles in the PL. We have studied photoluminescence (PL) from samples of Er-doped Si-rich silicon oxide (SRSO) annealed at for in , (FG1), (FG2), and , respectively, or subjected to double-step annealing processes. For the given film composition, the PL spectra of the samples annealed in , FG1, or FG2 are similar in shape but reveal small differences in the intensities of emission bands; while the spectra are qualitatively different in the case of oxidation. By combining the treatments of oxidation and annealing in FG1, the PL intensity of the SRSO matrix increases significantly; the emission from Si nanoclusters (Si-ncls) is also enhanced while the PL remains efficient. The effects of annealing gas ambients are discussed in terms of hydrogen passivation, Si oxynitridation and/or oxidation occurring in the film upon annealing and play different roles in the PL. Export citation and abstract BibTeX RIS