Raman spectrum of monoclinic semiconductor

The Raman-active phonons in semiconductor Cu2SnSe3 that crystallizes in the monoclinic structure with space group Cc were studied by measuring unpolarized Raman spectrum. The experimental Raman line wave numbers for the phonon modes were compared to those reported and to the results of lattice dynamical calculations based on simplified current models reported in the literature. From the factor group analysis of the zone-center vibrational modes, the symmetry of the observed Raman lines were tentatively assigned. The most intense A ′ mode at 178 cm−1; the lowest- and highest-frequency A ′ modes at 83 and 244 cm−1, respectively; A ″ modes at 204, 231 and 291 cm−1; and a band at about 363 cm−1 which probably corresponds to an overtone on the strong peak at 178 cm−1, have been observed in this compound.