Optical and electronic properties of thin bismuth-antimony films in the terahertz frequency range

The influence of antimony content x and a film thickness on dynamical terahertz conductivity and galvanomagnetic properties of thin-film bismuth antimonides Bi1-xSbx at room temperature is studied in this work by means of terahertz time-domain spectroscopy and galvanomagnetic measurements. It is shown that thin bismuth-antimony films have tunable optical response in the THz frequency range. The hyperbolic permittivity dispersion of an effective film-on-substrate structure is also reported. The studied thin-film materials can be applied in detection of terahertz radiation and in terahertz filtering, modulation, phase and polarization shifting, in sensing, imaging and communication systems which work at normal conditions.