Phonon and vibrational spectra of hydrogenated CdTe

This work presents far-infrared reflectivity spectra collected with synchrotron radiation on specially prepared CdTe monocrystals in the temperature region of 30-300 K. The investigated samples were of three different types characterized by the three different levels of hydrogenation-strong, middle, and low ones. In order to interpret the experimental data, the imaginary part of the dielectric function was evaluated by means of Kramers-Kronig transformation. To determine quantitatively the influence of hydrogen atoms on the phonon and vibrational spectra of hydrogenated CdTe crystals we used the special statistical model proposed in this paper. This model takes into account the tetrahedron as the basic structural unit and distinguishes the contribution of the hydrogen-bearing tetrahedra from the contribution of the hydrogen-free ones to the crystal phonon spectra. (c) 2006 American Institute of Physics.