1.5 µm room-temperature luminescence from Er-implanted oxygen-doped silicon epitaxial films grown by molecular beam epitaxy

Oxygen-doped Si epitaxial films (OXSEF) grown by molecular beam epitaxy and subsequently implanted with Er show room-temperature luminescence around l=1.54 mm. The 45-nm-thick films have an oxygen concentration of 10 at. % and were implanted with 7.8 X 10^l4 25 keV Er ions/cm². The luminescence was optically excited with the 514 nm line of an Ar ion laser and is attributed to intra-4f transitions in Er³⁺. Thermal annealing at 700-800°C is necessary to optimize the luminescence after implantation. Pure Si implanted and annealed under the same conditions does not show Er-related luminescence at room temperature. The emission from Er in OXSEF is attributed to the high concentration of oxygen in the films, which forms complexes with Er. The excitation of Er³⁺ is due to a photocarrier mediated mechanism.