Temperature dependent Raman scattering studies of three dimensional topological insulators Bi2Se3.

We investigate the temperature dependent (83K ⩽ T ⩽ 523K) frequency shift of 2A¹_g and 1E²_g phonon modes in the three dimensional topological insulator Bi₂Se₃, using Raman spectroscopy. The high quality single crystals of Bi₂Se₃ were grown using a modified Bridgman technique and characterized by Laue diffraction and high resolution transmission electron microscopy. A significant broadening in the line shape and red-shift in the frequencies were observed with increase in temperature. Polarized Raman scattering measurement shows a strong polarization effect of A¹_g and A²_g phonon modes which confirms the good quality single crystals of Bi₂Se₃. Temperature co-efficient for A¹_1g; E²_g , and A²_1g modes was estimated to be -1.44 × 10^-2, -1.94 ×10^-2, and -1.95 ×10^-2 cm^-1/K, respectively. Our results shed light on anharmonic properties of Bi₂Se₃. [ABSTRACT FROM AUTHOR]