In-plane anisotropic Raman response of layered In2Te5 semiconductor

This work presents a systematic study of phonon modes in Indium tellurides (In2Te5), a member of Pentatelluride M2Te5, where M = Al, Ga, and In, by Raman spectroscopy. We demonstrated the strong anisotropic Raman response for linearly polarized excitation, and the eight detected Raman characteristic peaks were further revealed by density functional perturbation theory calculations. All Raman mode shifts exhibit a linear temperature dependence. The first-order temperature coefficient (χ) of the In2Te5 Raman mode ranges from –0.00444 to –0.01557 cm−1/K. Our results shed light on phonon vibrational properties of In2Te5, attracting future research interest in group III–VI layered semiconductors.