Raman Spectroscopy of Bi2Se3-xTex (x= 0 to 3) Topological Insulator Crystals

TL;DR

This study investigates the vibrational properties of pure and mixed Bi2Se3-xTex topological insulator crystals using Raman spectroscopy, revealing atomic size effects and mode splitting in vibrational spectra.

Contribution

It provides detailed Raman spectral analysis of both binary and ternary tetradymite topological insulators, highlighting atomic size effects and mode deconvolution.

Findings

Atomic size influences Raman peak shifts.

In-plane Eg modes show peak broadening and splitting.

Presence of separate BiSe and BiTe vibrational modes.

Abstract

We report crystal growth and Raman spectroscopy characterization of pure and mixed bulk topological insulators. The series comprises of both binary and ternary tetradymite topological insulators. We analyzed in detail the Raman peaks of vibrational modes as out of plane Ag, and in plane Eg for both binary and ternary tetradymite topological insulators. Both out of plane Ag exhibit obvious atomic size dependent peak shifts and the effect is much lesser for the former than the latter. The situation is rather interesting for in plane Eg, which not only shows the shift but rather a broader hump like structure. The de convolution of the same show two clear peaks, which are understood in terms of the presence of separate in plane BiSe and BiTe modes in mixed tetradymite topological insulators. Summarily, various Raman modes of well-characterized pure and mixed topological insulator single crystals are reported and discussed in this article.