Doping effects on charge density instability in non-centrosymmetric PbxTaSe2

TL;DR

This study investigates how Pb doping affects vibrational and electronic properties in PbxTaSe2, revealing mode variations and potential charge density wave remnants, with implications for understanding doping-induced phase changes in layered materials.

Contribution

It provides new insights into the vibrational behavior and charge density wave phenomena in Pb-doped TaSe2 through Raman spectroscopy analysis.

Findings

Vibrational modes vary significantly with Pb concentration.

Additional low-frequency modes suggest remnant charge density waves or disorder.

Pb doping influences the electronic and vibrational properties of TaSe2.

Abstract

We report on the investigation of vibrational and electronic properties of the Pb doped dichalcogenide PbxTaSe2 using Raman scattering experiments. We observe a marked variation of the main vibrational modes with Pb concentration x. The concentration dependence of the vibrational modes resembles the dependence of the vibrational modes in TaSe2 on the number of crystallographic layers along the c axis direction [1]. The temperature and polarization dependence of Raman spectra of PbxTaSe2 revealed additional broad modes in the low frequency regime which are discussed in context of remnant charge density wave, induced disorder, or PbSe phase formed in the interface of Pb and TaSe2 layers.