Enhanced visible and near-infrared optical absorption in silicon supersaturated with chalcogens

We show that single-crystal silicon supersaturated with sulfur (S), selenium (Se), or tellurium (Te) displays a substantially enhanced absorption coefficient for light with wavelengths of 400 to 1600 nm. Alloys were prepared in silicon on insulator wafers by ion implantation followed by nanosecond pulsed laser melting. Measurements of the absorption coefficient were made by direct transmission through freestanding thin films and by spectroscopic ellipsometry.