Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study

Cui，Juan1,2; Li，Shasha2,3; Xia，Chengliang2; Chen，Yue2,4; He，Jiaqing1,5

2021-11-01

10.1016/j.jmat.2021.03.008

Journal of Materiomics   影响因子和分区

2352-8478

2352-8486

Various strategies for thermoelectric material optimization have been widely studied and used for promoting electrical transport and suppressing thermal transport. As a nontraditional method, pressure has shown great potential, as it has been applied to obtain a high thermoelectric figure of merit, but the microscopic mechanisms involved have yet to be fully explored. In this study, we focus on r-GeTe, a low-temperature phase of GeTe, and investigate the pressure effects on the electronic structure, electrical transport properties and anharmonic lattice dynamics based on density functional theory (DFT), the Boltzmann transport equations (BTEs) and perturbation theory. Electronic relaxation times are obtained based on the electron-phonon interaction and the constant relaxation time approximation. The corresponding electrical transport properties are compared with those obtained from previous experiments. Hydrostatic pressure is shown to increase valley degeneracy, decrease the band effective mass and enhance the electrical transport property. At the same time, the increase in the low-frequency phonon lifetime and phonon group velocity leads to an increase in lattice thermal conductivity under pressure. This study provides insight into r-GeTe under hydrostatic pressure and paves the way for a high-pressure strategy to optimize transport properties.

Electronic structure GeTe Pressure effect Transport properties

SCI

英语

第一 ; 通讯

WOS:000708847300002

2-s2.0-85116980450

Scopus

1.Shenzhen Key Laboratory of Thermoelectric Materials,Department of Physics,Southern University of Science and Technology,Shenzhen,518055,China
2.Department of Mechanical Engineering,The University of Hong Kong,SAR,Pokfulam Road,Hong Kong
3.School of Science,Nanjing University of Posts and Telecommunications,Nanjing,210023,China
4.HKU Zhejiang Institute of Research and Innovation,Lin A,1623 Dayuan Road,311305,China
5.Guangdong Provincial Key Laboratory of Energy Materials for Electric Power,Southern University of Science and Technology,Shenzhen,518055,China

Cui，Juan,Li，Shasha,Xia，Chengliang,et al. Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study[J]. Journal of Materiomics,2021,7(6):1190-1197.

Cui，Juan,Li，Shasha,Xia，Chengliang,Chen，Yue,&He，Jiaqing.(2021).Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study.Journal of Materiomics,7(6),1190-1197.

Cui，Juan,et al."Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study".Journal of Materiomics 7.6(2021):1190-1197.