Pressure and temperature dependence of Raman spectra and their anharmonic effects in Bi2Se3 single crystal

Abstract

We report here on Raman spectroscopic studies of Bi2Se3 single crystal synthesized by chemical vapor transport technique as a function of pressure (0–12GPa) and temperature (80–300K). Polarized Raman experiments in the back-scattering configuration were performed to determine the position of the two dominant first-order Raman-active modes, Eg2 and A1g2 at around 132 and 174cm−1 respectively. High pressure Raman measurements provides the evidence that Bi2Se3 single crystal undergoes first order phase transition above 10GPa. Isobaric and isothermal mode Gruneisen parameter have been determined from the temperature and pressure dependent Raman spectra for both Raman active modes of Bi2Se3 single crystal. The analysis of the experimental data showed that the temperature dependencies of the phonon frequencies and linewidths were well described by considering the contributions from thermal expansion and lattice anharmonicity.