Characteristics of light emission from mixture of spin-on glass and erbium oxide nanoparticles were investigated. Such erbium-doped silica thin films after furnace annealing have exhibited a strong room temperature photoluminescence (PL) at similar to 1.53 mu m. The PL intensity of the erbium-doped thin film after annealing at 1000 degrees C was 30 times higher than those after low-temperature annealing. The chemical environment of the erbium ion in the thin film after annealing has been studied by Time-of-Flight Secondary Ion Mass Spectrometry (SIMS). The SIMS result confirmed that Er-O-Si complex was favored and OH group was eliminated in the erbium-doped silica film sample after annealing. Hence we accounted for the PL enhancement of erbium-doped silica by furnace annealing. (C) 2007 Elsevier B.V. All rights reserved.