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X-ray powder diffraction studies of ordered vacancy compounds CuIn3Te5 and CuGa3Te5, prepared by the vertical Bridgman–Stockbarger technique, show that these materials exhibit a tetragonal chalcopyrite-related structure. The unit cell parameters a and c are, respectively, 6.1639(3) and 12.346(2) Å for CuIn3Te5, and 5.9321(8) and 11.825(4) Å for CuGa3Te5. From electrical resistivity characterization as a function of temperature a shallow acceptor level, with an activation energy lower than 30 meV, is found in both these compounds. Their direct energy gaps at room temperature are 1.013 and 1.092 eV for CuIn3Te5 and CuGa3Te5, respectively.

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A comparative study of the Raman spectra of Cu2BIICIVS4VI and Cu2BIICIVSe4VI(where B = Mn or Fe) magnetic quaternary semiconductor compounds with stannite-type structure (I4¯2m) has been done. Most of the fourteen Raman lines expected for these materials were observed in the spectra. The two strongest lines observed have been assigned to the IR inactive A11 and A12 stannite modes that originated from the motion of the S or Se anion around the Cu and CIV cations remaining at rest. The shift in the frequency of these two lines of about 150 cm−1 to lower energies observed in Cu2BIICIVSe4VI compounds as compared to those in Cu2BIICIVS4VI ones, can then be explained as due to the anion mass effect. Based on the fact that values of these frequencies depend mainly on anion mass and bond-stretching forces between nearest-neighbor atoms, the vibrational frequencies v¯(A12) and v¯(A12) of both modes for several Cu2BIICIVX4VI stannite compounds (where X = S, Se, or Te) very close to the experimental data reported for these materials were calculated from a simple model that relates these stretching forces to the anion-cation bond-distances.