Erbium in oxygen-doped silicon: Electroluminescence

Room-temperature electroluminescence at 1.54 μm is demonstrated in erbium-implanted oxygen-doped silicon (27 at. % O), due to intra-4f transitions of the Er3+. The luminescence is electrically stimulated by biasing metal-(Si:O, Er)-p+ silicon diodes. The 30-nm-thick Si:O, Er films are amorphous layers deposited onto silicon substrates by chemical-vapor deposition of SiH4 and N2O, doped by ion implantation with Er to a concentration up to ≊1.5 at. %, and annealed in a rapid thermal annealing furnace. The most intense electroluminescence is obtained in samples annealed at 400 °C in reverse bias under breakdown conditions and it is attributed to impact excitation of erbium by hot carriers injected from the Si into the Si:O, Er layer. The electrical characteristics of the diode are studied in detail and related to the electroluminescence characteristics. A lower limit for the impact excitation cross section of ≊6×10−16 cm2 is obtained.