Optimal Bandwidth for High Efficiency Thermoelectrics

Zhou, Jun; Yang, Ronggui; Chen, Gang; Dresselhaus, M. S.

doi:10.1103/physrevlett.107.226601

Cited by 95 publications

(95 citation statements)

References 27 publications

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“…Recently, we revisited this problem by studying the TE transport in a narrow conduction band using the tight-binding model along with a few most-used carrier scattering models. 25 We found that the optimal ZT cannot be obtained in an extremely narrow conduction band with zero energy variation of ) (E Ξ . However, there…”

Section: Introductionmentioning

confidence: 81%

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
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Following the idea that there exists an optimal bandwidth for maximizing the thermoelectric figure of merit (ZT), we conduct detailed calculations in this paper to search for the optimal ZT in Bi 2 Te 3 /Sb 2 Te 3 quantum dot (QD) nanocomposites (NCs) with Bi 2 Te 3 QDs uniformly embedded in Sb 2 Te 3 matrix where electron minibands are formed. The two-channel transport model, which considers both the miniband transport by the quantum-confined carriers and the background transport by the bulk-like carriers, is used for electrical transport, while the lattice thermal conductivity is modeled using the modified effective medium approximation. Simultaneous decrease of the lattice thermal conductivity and the Lorenz number leads to an enhanced ZT in QD NCs when the Seebeck coefficient is not dramatically decreased. The optimal structural parameters that result in optimal electronic structure for maximizing ZT are found, with the consideration of realistic carrier scattering physics including phonon bottleneck effect. The optimal QD size is found to be ~nm 6, and the optimal inter-dot distance depends on the QD size and the doping concentration. For a * Author to whom correspondence should be addressed: Ronggui.Yang@colorado.edu 2 given QD size, the maximum ZT is determined by the minimum of Lorenz number, which occurs when the quantum-confined carrier transport overwhelms the bulk-like carrier transport.

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Section: Introductionmentioning

confidence: 81%

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
Self Cite

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“…To optimize the thermal properties, various phonon engineering approaches were used to enhance phonon scattering and decrease κ L by having taken advantage of nanoinclusion [3][4][5][6][7][8][9][10][11][12][13] . A series of band structure engineering approaches were employed to improve the electrical properties [14][15][16][17][18][19][20] . Recently, we discovered that the electrical and thermal properties of TE materials could be simultaneously optimized through coexisting multi-localization transport behavior 21 .…”

Section: Magnetoelectric Interaction and Transport Behaviors In Magnementioning

confidence: 99%

Magnetoelectric interaction and transport behaviours in magnetic nanocomposite thermoelectric materials

et al. 2016

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How to suppress the performance deterioration of thermoelectric materials in the intrinsic excitation region remains a key challenge. The magnetic transition of permanent magnet nanoparticles from ferromagnetism to paramagnetism provides an effective approach for the solution of this challenge. Here we have designed and prepared the magnetic nanocomposite thermoelectric materials consisting of BaFe 12 O 19 nanoparticles (BaM-NPs) and Ba 0.3 In 0.3 Co 4 Sb 12 matrix. It is discovered that the electrical transport behaviors of the nanocomposites have been controlled by the magnetic transition of BaM-NPs from ferromagnetism to paramagnetism. BaM-NPs trap the elctrons below the Curie temperature (T C ) and release the trapped electrons above the T C , playing an "electron repository" role in maintaining high ZT. BaM-NPs produce two types of magnetoelectric effects of electron spiral motion and magnon-drag thermopower besides enhancing phonon scattering. Our work demonstrates that the thermoelectric performance deterioration in the intrinsic excitation region can be suppressed through the magnetic transition of permanent magnet nanoparticles.Thermoelectric (TE) materials have attracted much interest owing to the fascinating applications in recycling utilization of industrial waste heat and automobile exhaust heat, high-efficiency cooling of next-generation integrated circuits, and full-spectrum solar power generation 1,2 . The properties of TE materials are characterized by dimensionless figure of merit ZT=α 2 σT/(κ E +κ L ). Where T, α, σ, κ E and κ L are the absolute temperature, Seebeck coefficient, electrical conductivity, and the electronic and lattice components of the thermal conductivity (κ), respectively. To optimize the thermal properties, various phonon engineering approaches were used to enhance phonon scattering and decrease κ L by having taken advantage of nanoinclusion [3][4][5][6][7][8][9][10][11][12][13] . A series of band structure engineering approaches were employed to improve the electrical properties [14][15][16][17][18][19][20] . Recently, we discovered that the electrical and thermal properties of TE materials could be simultaneously optimized through coexisting multi-localization transport behavior 21 . However, TE materials have been facing a serious problem that the intrinsic excitation unavoidably results in the deterioration of high-temperature performance. Up to now, it remains a key challenge how to suppress the performance deterioration of TE materials in the intrinsic excitation region.Based on the Maxwell's electromagnetic theory, the charged particles (electrons and holes) are confined to circular paths or helixes and even trapped by magnetic impurities owing to the Lorentz force (F L ) 22 . To achieve excellent electrical transport properties, all semiconductor materials including various TE materials had been generally required to eliminate the magnetic impurities in the past decades. This understanding has limited the development of magnetic nanocomposite TE materials. Here we pr...

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“…The mobility is set to be μ ¼ 420 cm 2 =V s for each system and the scattering rate may be proportional to the density of final states (DOS). By assuming proportionality of the scattering rate with respect to the DOS, we obtain r ¼ þ0.5, r ¼ 0 and r ¼ −0.5 for 1D, 2D, and 3D systems, respectively [16]. Hereafter, we consider such different r values for the different dimensions.…”

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confidence: 99%

Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors

et al. 2016

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We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one-and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ, bulk semiconductors may give a higher power factor compared to the lower dimensional ones.

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Optimal Bandwidth for High Efficiency Thermoelectrics

Cited by 95 publications

References 27 publications

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
Self Cite

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
Self Cite

Magnetoelectric interaction and transport behaviours in magnetic nanocomposite thermoelectric materials

Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors

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Optimal Bandwidth for High Efficiency Thermoelectrics

Cited by 95 publications

References 27 publications

Optimal thermoelectric figure of merit in Bi2Te3/Sb2TeZhou1, Wang2, Sharp3 et al. 2012Phys. Rev. BSelf Cite

Optimal thermoelectric figure of merit in Bi2Te3/Sb2TeZhou1, Wang2, Sharp3 et al. 2012Phys. Rev. BSelf Cite

Magnetoelectric interaction and transport behaviours in magnetic nanocomposite thermoelectric materials

Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors

Contact Info

Product

Resources

About

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
Self Cite

Optimal thermoelectric figure of merit in Bi2Te3/Sb2Te
Zhou
¹
,
Wang
²
,
Sharp
³

et al. 2012
Phys. Rev. B
Self Cite