Optical characterization of nanostructured β − FeSi₂ layers obtained by Fe⁺ implantation

In this work, we present a comprehensive analysis of nanostructured β − FeSi₂ layers obtained by 40 keV Fe ion implantation in silicon, followed by rapid thermal annealing. A series of chemical, structural and optical characterizations of the samples were performed. Our results establish the formation of a 26.6 nm thick layer consisting of β − FeSi₂ nanocrystals, with an average size of 4.8 nm, embedded in the Si substrate. Optical excitation of the sample leads to a photoluminescence signal with an extremely narrow peak (1 nm full width at half maximum) at 1456 nm. This sharp emission is comparable with the radiation of semiconductor lasers and therefore, this β − FeSi₂ nanostructured layer is of interest for the fabrication of new optoelectronic devices in the near-infrared region. (paper)