Two-phonon processes in II-VI semiconductors investigated with terahertz time-domain spectroscopy

Summary form only given. Terahertz time-domain spectroscopy (THz-TDS) is meanwhile a well proved technique to determine the complex dielectric function of materials in the far-infrared (FIR) regime of the electromagnetic spectrum. Especially in accurate measurements of the optical properties of crystals at frequencies below the transverse optical phonon (TO) resonance, THz-TDS is a powerful alternative to classical methods like Raman and FTIR spectroscopy. We investigate the temperature-dependent FIR properties of the II-VI semiconductor compounds ZnTe and CdTe in the frequency range between 200 GHz and 2.3 THz.