We have characterized the mechanism of energy transfer from Si nanoparticles to Er3+ ions in different silicate glasses, namely soda-lime and aluminium silicates, and made the comparison with pure silica. By means of a multi-implantation scheme we have formed a 350 nm thick glass layer with a uniform Si excess (5% or 15% atomic excess) and an Er distribution. Several Er doses were chosen so that the resulting Er peak concentration could vary from 2 × 1019 up to 6 × 1020 cm−3. Fused silica wafers coimplanted in the same conditions were used as a reference material in order to compare the different efficiency and mechanisms of Er emission as a function of the host silicate composition. Thermal treatment at low temperature has been performed to enhance the photoluminescence around 1540 nm. Large PL emission, compared to structures doped only with Er, has been successfully detected in all co-implanted glasses, with similar intensity. Moreover, we have measured PL lifetimes from 2.5 to 12 ms (depending on the Er dose and Si excess), and estimated an Er effective excitation cross-section of the order of 1 × 10−17 cm2.