Ab initio and Experimental Study of Vibrational Properties of In-=SUB=-2-=/SUB=-Se-=SUB=-3-=/SUB=-

Abstract

The results of investigation of the vibrational properties of the semiconductor compound In2Se3: by the density functional perturbation theory (DFPT) and experimentally using Raman spectroscopy are presented. Comparison of Raman scattering measurements and results of calculations of lattice dynamics allowed us to identify four Raman active modes found at 91.28, 104.5, 182.68 and 193.6 cm-1. The phonon modes were identified by considering the point group symmetry. The results of identification of phonon modes confirmed the R3m-symmetry of the α-In2Se3 phase. A comparison is also made with the results of the experimental data available in the literature obtained by the method of Raman spectroscopy. The calculated frequencies and symmetries of the phonon modes at the center of the Brillouin zone are in good agreement with the experimental data. Keywords: In2Se3, Raman scattering, IR- and Raman active modes, phonon dispersion, phonon density of states.