Figure 3.

(a) Calculated infrared reflectance spectra at near-normal incidence θ_i ≈ 0 for the GeC/Si (001) epilayers of different film thicknesses. The results include bulk zb GeC as well as 8 μm, 6 μm, 4 μm, 2 μm, 1 μm, 0.5 μm, and 0.05 μm thick films. (b) Reflectivity spectra of 4 μm thick GeC/Si (001) epifilm, with blue- and red-colored lines indicating undoped η = 0 and n-doped η = 0.5 E+19 cm⁻³, respectively. (c) Polarization-dependent reflectivity of 0.5 μm thick GeC/Si (001) epifilm at oblique incident angle θ_i = 45°, where blue- and red-colored lines indicate s- and p-polarization spectra. The positions of ${\mathsf{\omega }}_{\mathrm{TO}}$and ${\mathsf{\omega }}_{\mathrm{LO}}$modes of GeC are also marked (see text).