Optical Characterization of β-FeSi₂ Thin Films Prepared by Femtosecond Laser Ablation

Iron disilicide thin films are prepared on fused quartz using femtosecond laser deposition (FsPLD) with a FeSi₂ alloy target. X-ray diffraction results indicate the films are single-phase, orthorhombic, β-FeSi₂. Field scanning electron microscopy, high resolution transmission electron microscopy, UV--VIS--NIR spectroscopy and Raman microscope are used to characterize the structure,
composition, and optical properties of the β-FeSi₂ films. Normal incidence spectral transmittance and reflectance data indicate a minimum, direct energy gap of 0.85eV. The two most intense lines of Raman scattering peaked at 181.3cm^-1 and 235.6cm^-1 for the film on fused quartz, and at 191.2cm^-1 and 243.8cm^-1 for the film on Si (100), are observed.