Modification of the vibrational spectra of Cd1-xZnxTe semiconductor alloys

An analysis is made of the lattice reflection spectra of Cd 1−x Zn x Te (x=0-0.5) alloys by the Kramers-Kronig and dispersion methods. This involves reconstruction of the dielectric function of a crystalline alloy e(ω) = e'(ω) + ie″(w) from the reflection spectra, followed by decomposition of the function e″ into Lorentzian profiles of lattice oscillators. The frequencies of the lattice oscillators obtained for different alloy compositions are distributed between four Cd−Te vibrational modes and four Zn−Te modes, in accordance with the model structure of the alloy Cd 1−x Zn x Te formed by five basic Cd(4−n)Zn(n)Te cells (n=0,1,2,3,4) from tetrahedrally arranged Cd and Zn cations around the shared Te anion