Electron-phonon coupling and quantum correction to topological magnetoconductivity in 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Bi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>Ge</mml:mi><mml:msub><mml:mi>Te</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

Singh, Niraj K.; Rawat, Divya; Dey, Dibyendu; Elsukova, Anna; Persson, Per O. Å.; Eklund, Per; Taraphder, A.; Soni, Ajay

doi:10.1103/physrevb.105.045134

“…We have estimated the phonon lifetime (τ i ) with the help of the relation : τ i = 1/(2πc(FWHM) i ) where (FWHM) i is the full width at half-maxima of the Raman active mode. [58,59] The obtained room temperature phonon lifetime of all the Raman modes is extremely low and varies from 0.3-1 ps (Figure 3b and Figure S5, Supporting Information). The suppressed phonon lifetimes indicate multiple phonons scattering pathways as both scattering rate and phonon lifetime are inversely related to each other.…”

Section: Resultsmentioning

confidence: 99%

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Pathak

¹

,

Dutta

²

,

Srivastava

³

et al. 2022

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Intrinsically low lattice thermal conductivity (k lat ) while maintaining the high carrier mobility (μ) is of the utmost importance for thermoelectrics. Topological insulators (TI) can possess high μ due to the metallic surface states. TIs with heavy constituents and layered structure can give rise to high anharmonicity and are expected to show low k lat .Here, we demonstrate that Bi 1.1 Sb 0.9 Te 2 S (BSTS), which is a 3D bulk TI, exhibits ultra-low k lat of 0.46 Wm À 1 K À 1 along with high μ of � 401 cm 2 V À 1 s À 1 . Sound velocity measurements and theoretical calculations suggest that chemical bonding hierarchy and high anharmonicity play a crucial role behind such ultra-low k lat . BSTS possesses low energy optical phonons which strongly couple with the heat carrying acoustic phonons leading to ultra-low k lat . Further, Cl has been doped at the S site of BSTS which increases the electron concentration and reduces the k lat resulting in a promising ntype thermoelectric figure of merit (zT) of � 0.6 at 573 K.

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“…All the modes show a decrease in the phonon frequency with the increase in temperature (Figure S4, Supporting Information). We have estimated the phonon lifetime ( τ i ) with the help of the relation : τ i =1/(2π c (FWHM) i ) where (FWHM) i is the full width at half‐maxima of the Raman active mode [58, 59] . The obtained room temperature phonon lifetime of all the Raman modes is extremely low and varies from 0.3–1 ps (Figure 3b and Figure S5, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Pathak

¹

,

Dutta

²

,

Srivastava

³

et al. 2022

Self Cite

View full text Add to dashboard Cite

Intrinsically low lattice thermal conductivity (k lat ) while maintaining the high carrier mobility (μ) is of the utmost importance for thermoelectrics. Topological insulators (TI) can possess high μ due to the metallic surface states. TIs with heavy constituents and layered structure can give rise to high anharmonicity and are expected to show low k lat .Here, we demonstrate that Bi 1.1 Sb 0.9 Te 2 S (BSTS), which is a 3D bulk TI, exhibits ultra-low k lat of 0.46 Wm À 1 K À 1 along with high μ of � 401 cm 2 V À 1 s À 1 . Sound velocity measurements and theoretical calculations suggest that chemical bonding hierarchy and high anharmonicity play a crucial role behind such ultra-low k lat . BSTS possesses low energy optical phonons which strongly couple with the heat carrying acoustic phonons leading to ultra-low k lat . Further, Cl has been doped at the S site of BSTS which increases the electron concentration and reduces the k lat resulting in a promising ntype thermoelectric figure of merit (zT) of � 0.6 at 573 K.

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“…Moreover, A IV B V 2 C VI 4 compounds show the characteristics beneficial for further reduction of 𝜅 L , such as cation disorder, [25] van der Waals gap, [17,26] and notable electron-phonon coupling. [27] Te-based A IV B V 2 C VI 4 compounds have been widely studied, demonstrating their potential as topological insulators [28,29] and phase change materials. [30,31] However, as TE materials, they are restricted by the extremely low PF.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover,

{{\mathrm{A}}}^{{\mathrm{IV}}}{\mathrm{B}}_2^{\mathrm{V}}{\mathrm{C}}_4^{{\mathrm{VI}}}

compounds show the characteristics beneficial for further reduction of κ L , such as cation disorder, [ 25 ] van der Waals gap, [ 17,26 ] and notable electron‐phonon coupling. [ 27 ]…”

Section: Introductionmentioning

confidence: 99%

Discovery of the Layered Thermoelectric Compound GeBi₂Se₄ and Accelerating Its Performance Optimization by Machine Learning

Wang,

Li

et al. 2023

Adv Materials Technologies

1

0

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Searching for new materials with intrinsically low lattice thermal conductivity is crucial for the exploration of high‐performance thermoelectric materials. Herein, the layered compound GeBi2Se4 with intrinsically low lattice thermal conductivity is discovered, and its thermoelectric performance optimization is accelerated by machine learning. The ultralow lattice thermal conductivity of 0.53 W m−1 K−1 at room temperature for the GeBi2Se4 sample can be ascribed to the large anharmonicity and miscellaneous crystal defects. By alloying tellurium (Te) at the selenium (Se) site, the lattice thermal conductivity is further reduced due to the alloy scattering effect and chemical bond softening while the density‐of‐states effective mass of electrons is significantly increased. Finally, the best n‐type thermoelectric GeBi2Se1.9Te2.1 sample with a dimensionless figure of merit zT of 0.56 at 460 K is screened out by machine learning and verified by experiments, which increases by 140% in comparison with the pristine GeBi2Se4.

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Electron-phonon coupling and quantum correction to topological magnetoconductivity in Bi2GeTe4

Cited by 17 publications

References 46 publications

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Discovery of the Layered Thermoelectric Compound GeBi₂Se₄ and Accelerating Its Performance Optimization by Machine Learning

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Electron-phonon coupling and quantum correction to topological magnetoconductivity in Bi2GeTe4

Cited by 17 publications

References 46 publications

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi1.1Sb0.9Te2S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi1.1Sb0.9Te2S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi1.1Sb0.9Te2S

Discovery of the Layered Thermoelectric Compound GeBi2Se4 and Accelerating Its Performance Optimization by Machine Learning

Contact Info

Product

Resources

About

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Strong Anharmonicity‐Induced Low Thermal Conductivity and High n‐type Mobility in the Topological Insulator Bi_1.1Sb_0.9Te₂S

Discovery of the Layered Thermoelectric Compound GeBi₂Se₄ and Accelerating Its Performance Optimization by Machine Learning