Optical characterization of β-FeSi2 layers formed by ion beam synthesis

Abstract Thin β -FeSi 2 layers have been prepared by ion beam synthesis (IBS) on (1 1 1)Si substrates. The obtained samples have been characterized by means of infrared and Raman spectroscopies. The infrared (IR) transmittance spectra show the absorption at 310 cm −1 as an indication of the initial nucleation of β -FeSi 2 precipitates during the implantation of iron into silicon substrate. The main feature of the photoluminescence (PL) measurements at 12 K in the β -FeSi 2 /(1 1 1)Si samples annealed at 850 °C for 90 min is an intense peak localized at 0.811 eV. This peak is assigned to optical radiative transitions intrinsic to β -FeSi 2 .