Investigating the effect of temperature dependent many-body interactions on bulk electronic structures and the robust nature of (001) surface states of SnTe

Sihi, Antik; Pandey, Sudhir K.

doi:10.48550/arxiv.2008.05694

Cited by 3 publications

(3 citation statements)

References 58 publications

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“…Another approach is by using conventional statistical mechanical approach to calculate G. In the temperature Green's function method, the concept of temperature is introduced through Matsubara-time. This method is easy to adopt in self-consistent calculations [55][56][57][58].…”

Section: Brief Description Of the Calculation Methodsmentioning

confidence: 99%

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Shastri

Pandey

2021

J. Phys.: Condens. Matter

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This work, presents a study of lifetime of carriers due to intrinsic scattering mechanisms viz. electron-electron interaction (EEI), electron-phonon interaction (EPI) and phonon-phonon interaction (PPI) in a promising half-Heusler thermoelectric FeVSb. Using the full-GW method, the effect of EEI and temperature on the valence and conduction band extrema and band gap are studied. The lifetime of carriers with temperature are estimated at these band extrema. At 300 K, estimated value of lifetime at VBM (CBM) is ∼1.91 × 10 −14 s (∼2.05 × 10 −14 s). The estimated ground state band gap considering EEI is ∼378 meV. Next, the effect of EPI on the lifetime of electrons and phonons with temperature are discussed. The comparison of two electron lifetimes suggests that EEI should be considered in transport calculations along with EPI. The average acoustic, optical and overall phonon lifetimes due to EPI are studied with temperature. Further, the effect of PPI is studied by computing average phonon lifetime for acoustic and optical phonon branches. The lifetime of the acoustic phonons are higher compared to optical phonons which indicates acoustic phonons contribute more to lattice thermal conductivity (κ ph ). The comparison of phonon lifetime due to EPI and PPI suggests that, above 500 K EPI is the dominant phonon scattering mechanism and cannot be ignored in κ ph calculations. Lastly, a prediction of the power factor and figure of merit of n-type and p-type FeVSb is made by considering the temperature dependent carrier lifetime for the electronic transport terms. This study shows the importance of considering EEI in electronic transport calculations and EPI in phonon transport calculations in FeVSb. Our study is expected to provide results to further explore the thermoelectric transport in this material.

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Section: Brief Description Of the Calculation Methodsmentioning

confidence: 99%

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Shastri

Pandey

2021

J. Phys.: Condens. Matter

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“…Another approach is by using conventional statistical mechanical approach to calculate G. In the temperature Green's function method, the concept of temperature is introduced through Matsubaratime. This method is easy to adopt in self-consistent calculations [40][41][42][43].…”

Section: Brief Description Of the Calculation Methodsmentioning

confidence: 99%

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Shastri¹,

Pandey²

2021

Preprint

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This work, presents a study of lifetime of carriers due to intrinsic scattering mechanisms viz. electron-electron (EEI), electron-phonon (EPI) and phonon-phonon interactions (PPI) in a promising half-Heusler thermoelectric FeVSb. Using the full-GW method, the effect of EEI and temperature on the valence and conduction band extrema and band gap are studied. The lifetime of carriers with temperature are estimated at these band extrema. At 300 K, estimated value of lifetime at VBM (CBM) is ∼1.91 x10 −14 s (∼2.05 x10 −14 s). The estimated ground state band gap considering EEI is ∼378 meV. Next, the effect of EPI on the lifetime of electrons and phonons with temperature are discussed. The comparison of two electron lifetimes suggests that EEI should be considered in transport calculations along with EPI. The average acoustic, optical and overall phonon lifetimes due to EPI are studied with temperature. Further, the effect of PPI is studied by computing average phonon lifetime for acoustic and optical phonon branches. The lifetime of the acoustic phonons are higher compared to optical phonons which indicates acoustic phonons contribute more to lattice thermal conductivity (κ ph ). The comparison of phonon lifetime due to EPI and PPI suggests that, above 500 K EPI is the dominant phonon scattering mechanism and cannot be ignored in κ ph calculations. Lastly, a prediction of the power factor and figure of merit of n-type and p-type FeVSb is made by considering the temperature dependent carrier lifetime for the electronic transport terms. This study shows the importance of considering EEI in electronic transport calculations and EPI in phonon transport calculations. Our study is expected to provide results to further explore the thermoelectric transport in this material.

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“…1 and 2 are used to compute the C V and F , respectively, which are implemented in phonopy code. 23 This method of calculating C V and F are also executed by other works 26,27 . The calculated values of C V and F in the temperature range 0 − 1400 K are shown in Fig.…”

Section: B Thermal Propertiesmentioning

confidence: 99%

Dependency of XC functionals and role of 3s(2p) orbitals of Co(Si) as core/valence states on the vibrational and thermodynamic properties of CoSi

Sk,

Pandey

2020

Preprint

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First-principles phonon calculations along with density functional theory (DFT) play an important role to study the dynamical and thermal properties of materials. Here, we investigate the effect of exchange correlation (XC) functionals on the vibrational and thermodynamic properties of CoSi. The role of 3s(2p) orbitals of Co(Si) as core/valence states on the phonon properties of this compound is also studied. Phonon calculations are carried out by finite displacement method with supercell approach using equilibrium crystal structures obtained from DFT calculations. The calculated results are compared with the existing experiment. Three XC functionals, viz., LDA, PBEsol and SCAN are used for calculating the phonon dispersion, phonon density of states (DOS)/partial DOS and thermal properties of this compound. SCAN is found to give the highest phonon frequency of ∼56 meV which is in good agreement with the experimental value, while LDA (PBEsol) gives ∼54 (∼55) meV. The zero-point energy is calculated as ∼ 10 kJ/mol for all the functionals. The Debye temperatures (ΘD) are computed as ∼626 K, ∼638 K and ∼650 K for LDA, PBEsol and SCAN, respectively. The ΘD obtained from LDA gives the good agreement with the reported value. The phonon dispersion and phonon DOS are found to be dependent whether 3s(2p) orbitals of Co(Si) are considered as core or valence states. But, this orbital dependency is seemed to be insignificant on the thermal properties of this compound.

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Investigating the effect of temperature dependent many-body interactions on bulk electronic structures and the robust nature of (001) surface states of SnTe

Cited by 3 publications

References 58 publications

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Studying the lifetime of charge and heat carriers due to intrinsic scattering mechanisms in FeVSb half-Heusler thermoelectric

Dependency of XC functionals and role of 3s(2p) orbitals of Co(Si) as core/valence states on the vibrational and thermodynamic properties of CoSi

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