Raman and FIR reflection spectroscopy of ZnP2 and CdP2 single crystals

The permittivity models for the ZnP2 and CdP2 crystals were determined by analysis of the far infrared reflection and Raman scattering spectra. For the first time, the dielectric permittivity is presented in an additive form containing the plasmon and phonon parts. The influence of a concentration of the free charge carriers on reflection spectra of doped CdP2 is represented.