Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study
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,...
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Elsevier
2021-11-01
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| Series: | Journal of Materiomics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352847821000563 |
| _version_ | 1797716467428360192 |
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| author | Juan Cui Shasha Li Chengliang Xia Yue Chen Jiaqing He |
| author_facet | Juan Cui Shasha Li Chengliang Xia Yue Chen Jiaqing He |
| author_sort | Juan Cui |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-03-12T08:21:53Z |
| format | Article |
| id | doaj.art-97e931939fee4892b1df588b4fad038d |
| institution | Directory Open Access Journal |
| issn | 2352-8478 |
| language | English |
| last_indexed | 2024-03-12T08:21:53Z |
| publishDate | 2021-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materiomics |
| spelling | doaj.art-97e931939fee4892b1df588b4fad038d2023-09-02T18:26:53ZengElsevierJournal of Materiomics2352-84782021-11-017611901197Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles studyJuan Cui0Shasha Li1Chengliang Xia2Yue Chen3Jiaqing He4Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China; Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, SAR, Hong Kong, ChinaDepartment of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, SAR, Hong Kong, China; School of Science, Nanjing University of Posts and Telecommunications, Nanjing, 210023, ChinaDepartment of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, SAR, Hong Kong, ChinaDepartment of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, SAR, Hong Kong, China; HKU Zhejiang Institute of Research and Innovation, 1623 Dayuan Road, Lin A, 311305, China; Corresponding author. Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, SAR, Hong Kong, China.Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China; Guangdong Provincial Key Laboratory of Energy Materials for Electric Power, Southern University of Science and Technology, Shenzhen, 518055, China; Corresponding author. Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.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.http://www.sciencedirect.com/science/article/pii/S2352847821000563GeTePressure effectElectronic structureTransport properties |
| spellingShingle | Juan Cui Shasha Li Chengliang Xia Yue Chen Jiaqing He Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study Journal of Materiomics GeTe Pressure effect Electronic structure Transport properties |
| title | Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study |
| title_full | Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study |
| title_fullStr | Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study |
| title_full_unstemmed | Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study |
| title_short | Pressure effects on the electrical transport and anharmonic lattice dynamics of r-GeTe: A first-principles study |
| title_sort | pressure effects on the electrical transport and anharmonic lattice dynamics of r gete a first principles study |
| topic | GeTe Pressure effect Electronic structure Transport properties |
| url | http://www.sciencedirect.com/science/article/pii/S2352847821000563 |
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