Optical Properties and Electron–Phonon Interactions of CdTe1-XSex(In) Single Crystal

The far-infrared reflectivity spectra of CdTe0.97Se0.03 and CdTe0.97Se0.03(In) single crystals were measured at different temperatures. The analysis of the far-infrared spectra was carried out by a fitting procedure based on the dielectric function which includes spacious distribution of free carrier as well as their influence on the plasmon–phonon interaction. We found that the long wavelength optical phonon modes of CdTe1-xSex mixed crystals exhibit a two-mode behavior. The local In mode at about 160 cm−1 is observed. In both samples, a surface layer with a low concentration of free carriers is formed.