Temperature dependence of Raman-active optical phonons in Bi_2Se_3 and Sb_2Te_3

TL;DR

This study investigates how Raman-active optical phonons in Bi_2Se_3 and Sb_2Te_3 vary with temperature, revealing their potential for non-contact thermometry in devices across a broad temperature spectrum.

Contribution

It provides a detailed analysis of temperature-dependent phonon behavior in Bi_2Se_3 and Sb_2Te_3 using Raman spectroscopy, highlighting their application in temperature sensing.

Findings

Phonon peak positions shift with temperature in both materials.

Linewidth broadening correlates with temperature due to anharmonic effects.

Raman spectroscopy can serve as a tool for thermometry in these materials.

Abstract

Inelastic light scattering spectra of Bi_2Se_3 and Sb_2Te_3 single crystals have been measured over the temperature range from 5 K to 300 K. The temperature dependence of dominant A^{2}_{1g} phonons shows similar behavior in both materials. The temperature dependence of the peak position and linewidth is analyzed considering the anharmonic decay of optical phonons and the material thermal expansion. This work suggests that Raman spectroscopy can be used for thermometry in Bi_2Se_3- and Sb_2Te_3-based devices in a wide temperature range.