Drude–Smith–Lorentz type dielectric property of semimetal SiTe2 crystal in terahertz range

Silicon ditelluride (SiTe 2 ) has attracted significant attention due to its semimetal electronic and optical properties. In this study, we used terahertz time-domain spectroscopy (THz-TDS) to investigate the THz dielectric response. The measured complex refractive index, complex dielectric constant, and complex conductivity exhibit pronounced carrier features in the THz range. Both the dielectric constant and conductivity could be fitted by Drude-Smith-Lorentz model. The fitting results reveal that the dielectric response of SiTe 2 in terahertz range arises from the combined effects of free carrier transport and backscattering. This study systematically elucidates the dielectric response characteristics of SiTe 2 in the THz range, which provides a foundation for the design and modeling of SiTe 2 -based THz optoelectronic devices.