Optically active Er+3 in silica films, which are suitable for silicon-based optical applications, have been prepared by a sol-gel deposition process with high Er atomic concentrations of 6 and 12 %, followed by furnace annealing. Films were characterized for their thickness, index of refraction, and photoluminescence at room temperature. Photoluminescence yield is strongly enhanced for vacuum annealing in the temperature range 500-750 °C. Reasonable room-temperature photoluminescence is also observed for annealing at 1000 °C. These results demonstrate the viability of incorporating Er at high concentrations.