By analyzing Raman spectra, a comparative study was made of the lattice vibrational modes in CuInTe2 and ordered defect compounds. It was found that Raman lines in ordered defect compounds appeared at almost the same frequency as in CuInTe2. This was explained by suggesting that the cation vacancy should not be considered as being simply an empty site in the lattice, but instead as a localized region of positive Coulomb potential which attracted the valence electrons of surrounding anions. It was proposed that the vacancy-Te force constant which arose from the positive potential was of the same magnitude as the Cu-Te stretching bond.

Raman Spectra of CuInTe2, CuIn3Te5 and CuIn5Te8 Ternary Compounds. C.Rincón, S.M.Wasim, G.Marín, E.Hernández, J.M.Delgado, J.Galibert: Journal of Applied Physics, 2000, 88[6], 3439-44