Strong room-temperature infrared emission from Er-implanted porous Si

This communication demonstrates a strong, room-temperature (RT), infrared (IR) (1.54 μm) emission from Er-implanted red-emitting (peaked at 1.9 eV) porous silicon (Er:PSi). Erbium was implanted into porous Si, bulk Si, and quartz with a dose of 1015/cm2 at 190 keV and annealed for 30 minutes in N2 at temperatures ranging from 500 °C to 900 °C under identical conditions. No RT IR emission was observed from Er implanted quartz and silicon after annealing at 650 °C (although after annealing at 900 °C very weak emission was observed from quartz at 9 K). The highest RT emission intensity at 1.54 μm was from Er:PSi with a peak concentration of 1.5×1020/cm3 and annealed at 650 °C. Even the luminescence intensity from Er:PSi annealed at 500 °C was 26 times higher than that observed from Er-implanted quartz at 400 keV and annealed at 900 °C. A reduction in photoluminescence (PL) intensity of about a factor of two from Er:PSi over the 9 to 300 K temperature range was observed which is consistent with Er in wide band gap materials.