Hierarchical structures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST)

Wang, Siqing; Xiao, Yu; Chen, Yongjin; Peng, Shang; Wang, Dongyang; Hong, Tao; Yang, Zhi; Sun, Yuan; Gao, Xiang; Zhao, Li‐Dong

doi:10.1039/d0ee03459b

“…SrTe particles of similar shapes were observed in both Figure 11(B,D), whereas for the 8% SrTe‐alloyed sample, both small‐ and large‐sized SrTe secondary phases (having sizes in the range of 5–16 nm) with comparable amounts were obtained (Figure 11(E)). 220 Along with the atomic‐scale point defects, mesoscale dislocations, and grain boundaries, the high‐range defect‐size distribution of nanostructures can form all‐scale hierarchical architectures in solid materials, which has been proven to be the most effective approach to suppress the heat‐carrying phonon transport, strengthen phonon scattering, and thus reduce κ lat by minimizing τ 26,87,88,91,93,220,221 . κ lat for PbTe and Na‐doped PbTe‐SrTe decreased with an increase in the fraction of SrTe and reached extremely low values for the PbTe system (Figure 11(F)).…”

Section: Extrinsic Sources For Slowing Down the Heat Transportmentioning

confidence: 99%

“…Three‐dimensional (3D) body defects effectively scatter phonons with ranged frequencies owing to the different sizes of nanoprecipitates, secondary phases, and porous structures 21,22,79–85 . The introduction of multiscale extrinsic defects to reduce κ lat has become a very advanced approach in the thermoelectric field 26,86–94 . Additionally, the new concepts of atomic ordering and high‐entropy engineering have recently been found to be effective in decreasing κ lat and enhancing the ZT values of various materials 27,95 .…”

Section: Introductionmentioning

confidence: 99%

Slowing down the heat in thermoelectrics

Qin

¹

,

Wang

²

,

Zhao

³

2021

InfoMat

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Heat transport has various applications in solid materials. In particular, the thermoelectric technology provides an alternative approach to traditional methods for waste heat recovery and solid‐state refrigeration by enabling direct and reversible conversion between heat and electricity. For enhancing the thermoelectric performance of the materials, attempts must be made to slow down the heat transport by minimizing their thermal conductivity (κ). In this study, a continuously developing heat transport model is reviewed first. Theoretical models for predicting the lattice thermal conductivity (κlat) of materials are summarized, which are significant for the rapid screening of thermoelectric materials with low κlat. Moreover, typical strategies, including the introduction of extrinsic phonon scattering centers with multidimensions and internal physical mechanisms of materials with intrinsically low κlat, for slowing down the heat transport are outlined. Extrinsic defect centers with multidimensions substantially scatter various‐frequency phonons; the intrinsically low κlat in materials with various crystal structures can be attributed to the strong anharmonicity resulting from weak chemical bonding, resonant bonding, low‐lying optical modes, liquid‐like sublattices, off‐center atoms, and complex crystal structures. This review provides an overall understanding of heat transport in thermoelectric materials and proposes effective approaches for slowing down the heat transport to depress κlat for the enhancement of thermoelectric performance.

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“…To optimize the electron and phonon transport, several innovative strategies have been deployed where PbTe, GeTe and SnSe have been considered to be highly effective. [7][8][9][10][11][12][13][14][15][16][17][18][19] However,t he Pb-toxicity in PbTea nd high performance in only in single crystals of SnSe with weak mechanical proper-ties and strong anisotropic nature,a re probably not appropriate for the future energy management. On the other hand the high cost of Ge in GeTel imits its use in various applications.…”

Section: Introductionmentioning

confidence: 99%

“…Thus, decoupling the electronic and thermal transport with maximization of power factor ( S 2 σ ) and minimization of thermal conductivity are desirable to develop efficient TE material. To optimize the electron and phonon transport, several innovative strategies have been deployed where PbTe, GeTe and SnSe have been considered to be highly effective [7–19] . However, the Pb‐toxicity in PbTe and high performance in only in single crystals of SnSe with weak mechanical properties and strong anisotropic nature, are probably not appropriate for the future energy management.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Band Convergence and Ultra‐Low Thermal Conductivity Lead to High Thermoelectric Performance in SnTe

Pathak

¹

,

Sarkar

²

,

Biswas

³

2021

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SnTe, as tructural analogue of champion thermoelectric (TE) material PbTe, has recently attracted wide attention for TE energy conversion. Herein, we demonstrate ac o-doping strategy to improve the TE performance of SnTe via simultaneous modulation of electronic structure and phonon transport. The electrical transport is optimizedb y 3mol %A gd oping in self-compensated SnTe( i.e., Sn 1.03 Te). Further,Mgdoping in SnAg 0.03 Te resulted in highly converged valence bands,w hich enhanced the Seebeck coefficient markedly.T he energy gap between two uppermost valence bands (DE v )decreases to 0.10 eV in Sn 0.92 Ag 0.03 Mg 0.08 Te compared to 0.35 eV in pristine SnTe. The optimizedp-type carrier concentration and highly converged valence bands gave ahigh power factor of ca. 27 mWcm À1 K À2 at 865 Ki nS n 0.92 Ag 0.03 Mg 0.08 Te. The lattice thermal conductivity of Sn 0.92 Ag 0.03 Mg 0.08 Te reached to an ultra-low value of % 0.23 Wm À1 K À1 at 865 Kd ue to the formation of MgTen anoprecipitates in SnTem atrix. These combined effects resulted in ah igh TE figure of merit, zT % 1.55 at 865 Ki nSn 0.92 Ag 0.03 Mg 0.08 Te.

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“…Thus, decoupling the electronic and thermal transport with maximization of power factor ( S 2 σ ) and minimization of thermal conductivity are desirable to develop efficient TE material. To optimize the electron and phonon transport, several innovative strategies have been deployed where PbTe, GeTe and SnSe have been considered to be highly effective [7–19] . However, the Pb‐toxicity in PbTe and high performance in only in single crystals of SnSe with weak mechanical properties and strong anisotropic nature, are probably not appropriate for the future energy management.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Band Convergence and Ultra‐Low Thermal Conductivity Lead to High Thermoelectric Performance in SnTe

Pathak

¹

,

Sarkar

²

,

Biswas

³

2021

View full text Add to dashboard Cite

SnTe, as tructural analogue of champion thermoelectric (TE) material PbTe, has recently attracted wide attention for TE energy conversion. Herein, we demonstrate ac o-doping strategy to improve the TE performance of SnTe via simultaneous modulation of electronic structure and phonon transport. The electrical transport is optimizedb y 3mol %A gd oping in self-compensated SnTe( i.e., Sn 1.03 Te). Further,Mgdoping in SnAg 0.03 Te resulted in highly converged valence bands,w hich enhanced the Seebeck coefficient markedly.T he energy gap between two uppermost valence bands (DE v )decreases to 0.10 eV in Sn 0.92 Ag 0.03 Mg 0.08 Te compared to 0.35 eV in pristine SnTe. The optimizedp-type carrier concentration and highly converged valence bands gave ahigh power factor of ca. 27 mWcm À1 K À2 at 865 Ki nS n 0.92 Ag 0.03 Mg 0.08 Te. The lattice thermal conductivity of Sn 0.92 Ag 0.03 Mg 0.08 Te reached to an ultra-low value of % 0.23 Wm À1 K À1 at 865 Kd ue to the formation of MgTen anoprecipitates in SnTem atrix. These combined effects resulted in ah igh TE figure of merit, zT % 1.55 at 865 Ki nSn 0.92 Ag 0.03 Mg 0.08 Te.

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Hierarchical structures lead to high thermoelectric performance in Cu_m+nPb₁₀₀Sb_mTe₁₀₀Se_2m (CLAST)

Abstract: Hierarchical microstructures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST) through synergistically optimizing carrier and phonon transport.

Cited by 53 publications

References 68 publications

Slowing down the heat in thermoelectrics

Slowing down the heat in thermoelectrics

Enhanced Band Convergence and Ultra‐Low Thermal Conductivity Lead to High Thermoelectric Performance in SnTe

Enhanced Band Convergence and Ultra‐Low Thermal Conductivity Lead to High Thermoelectric Performance in SnTe

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