Synergistic modulation of mobility and thermal conductivity in (Bi,Sb)<sub>2</sub>Te<sub>3</sub> towards high thermoelectric performance

Pan, Yu; Qiu, Yang; Witting, Ian T.; Zhang, Liguo; Fu, Chenguang; Li, Jingwei; Huang, Yi; Sun, Fu‐Hua; He, Jiaqing; Snyder, G. Jeffrey; Felser, Claudia; Li, Jing‐Feng

doi:10.1039/c8ee03225d

Cited by 131 publications

(142 citation statements)

References 30 publications

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“…Therefore, the zT s are usually high in tellurides and selenides, but they are low in sulfides. This is the general phenomenon that has been observed in those well‐known TE materials such as Bi 2 X 3 ‐, SnX‐, and PbX‐based compounds (X = S, Se, and Te) . As shown in Figure , the zT values gradually improve as the anion element change from S to Se and then to Te.…”

supporting

confidence: 52%

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

et al. 2019

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With the increasingly serious environmental pollution and intensified energy crisis, exploitation and utilization of new kinds of clean energy resources are imperative. Among them, thermoelectric (TE) conversion technology based on highperformance TE materials enables direct energy conversion between heat and electricity through the movement of internal phonons and charge carriers. [1][2][3][4] It has shown extensive and important prospects in power generation using industrial waste heat and electronic refrigeration. [5] The energy conversion efficiency of a TE material is mainly determined by its dimensionless figure of merit, defined as zT = σS 2 T/(κ L + κ e ), where σ, S, T, κ L , and κ e are the electrical conductivity, Seebeck coefficient, absolute temperature, lattice thermal conductivity, and electronic thermal conductivity, respectively. The general criteria for high zTs require high crystal symmetry for materials, many valleys (carrier pockets) near the Fermi level, heavy elements with small electronegativity differences between the constituent elements, or complex crystal structure, etc. [6][7][8][9][10] For the constituent elements in the same group such as S, Se, and Te, the heavy one (Te and Se) always has large atomic mass for low κ L and more covalent bonding character for large carrier mobility (µ H ) and thus outstanding electrical transports. [10] Therefore, the zTs are usually high in tellurides and selenides, but they are low in sulfides. This is the general phenomenon that has been observed in those well-known TE materials such as Bi 2 X 3 -, SnX-, and PbX-based compounds (X = S, Se, and Te). As shown in Figure 1, the zT values gradually improve as the anion element change from S to Se and then to Te. However, the case is different in Cu 2 X-based liquidlike TE materials that are among the hottest materials in recent TE study. They possess exceptionally low thermal conductivity and excellent zTs with the values of 1.7-1.9 for Cu 2 S, 1.5-2.3 for Cu 2 Se, and 0.4-1.1 for Cu 2 Te (see Figure 1). [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] It is quite abnormal and interesting that the zT in Cu 2 Te is lower than those in Cu 2 S and Cu 2 Se. As we known, tellurium is less electronegative, thus the chemical bonds between Cu and Te should be less ionic as compared with those in Cu 2 S and Cu 2 Se, which is beneficial for large µ H and electrical transports. Besides, the κ L in Cu 2 Te is expected lower than or similar to those in Cu 2 S and Cu 2 Se because tellurium is much heavier than sulfur and Most of the state-of-the-art thermoelectric (TE) materials exhibit high crystal symmetry, multiple valleys near the Fermi level, heavy constituent elements with small electronegativity differences, or complex crystal structure. Typically, such general features have been well observed in those well-known TE materials such as Bi 2 X 3 -, SnX-, and PbX-based compounds (X = S, Se, and Te). The performance is usually high in the materials with heavy constituent elements such as Te and Se, bu...

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supporting

confidence: 52%

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

et al. 2019

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“…To secure high thermoelectric performance, high zT is required . As the temperature is generally limited by the application conditions or the employed material itself, the dominating factors for enhancing zT lie in enhancing S 2 σ, which is generally defined as the power factor to describe the electrical performance, as well as in reducing κ . For metals or degenerate semiconductors under the assumption of parabolic band and energy‐independent scattering approximation, S can be expressed as

S = \frac{8 π^{2} k_{B}^{2}}{3 e h^{2}} \cdot m^{*} \cdot T {(\frac{π}{3 n})}^{\frac{2}{3}}

where k B is the Boltzmann constant, h is the Plank constant, and m * is the density of state effective mass.…”

Section: Introductionmentioning

confidence: 99%

Promising and Eco‐Friendly Cu₂X‐Based Thermoelectric Materials: Progress and Applications

et al. 2020

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Due to the nature of their liquid‐like behavior and high dimensionless figure of merit, Cu2X (X = Te, Se, and S)‐based thermoelectric materials have attracted extensive attention. The superionicity and Cu disorder at the high temperature can dramatically affect the electronic structure of Cu2X and in turn result in temperature‐dependent carrier‐transport properties. Here, the effective strategies in enhancing the thermoelectric performance of Cu2X‐based thermoelectric materials are summarized, in which the proper optimization of carrier concentration and minimization of the lattice thermal conductivity are the main focus. Then, the stabilities, mechanical properties, and module assembly of Cu2X‐based thermoelectric materials are investigated. Finally, the future directions for further improving the energy conversion efficiency of Cu2X‐based thermoelectric materials are highlighted.

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“…Recently, based on the two‐step sintering process, Pan et al. shifted the temperature of the maximum zT to ∼380 K by increasing the Sb content in Bi x Sb 2‐ x Te 3.2 as shown in Figure (a) . Increasing the Sb content, the bandgap and antisite defects concentration increased and the hole concentration increased from ∼1×10 19 cm −3 for Bi 0.5 Sb 1.5 Te 3 sample to ∼2 and ∼3×10 19 cm −3 for Bi 0.4 Sb 1.6 Te 3 and Bi 0.3 Sb 1.7 Te 3 samples, respectively.…”

Section: Shifting the Maximum‐zt Temperature For Bi2te3‐based Polycrymentioning

confidence: 98%

Tuning Optimum Temperature Range of Bi₂Te₃‐Based Thermoelectric Materials by Defect Engineering

Zhang

Fang

Liu

et al. 2020

Chemistry An Asian Journal

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Bi2Te3‐based solid solutions, which have been widely used as thermoelectric (TE) materials for the room temperature TE refrigeration, are also the potential candidates for the power generators with medium and low‐temperature heat sources. Therefore, depending on the applications, Bi2Te3‐based materials are expected to exhibit excellent TE properties in different temperature ranges. Manipulating the point defects in Bi2Te3‐based materials is an effective and important method to realize this purpose. In this review, we focus on how to optimize the TE properties of Bi2Te3‐based TE materials in different temperature ranges by defect engineering. Our calculation results of two‐band model revel that tuning the carrier concentration and band gap, which is easily realized by defects engineering, can obtain better TE properties at different temperatures. Then, the typical paradigms about optimizing the TE properties at different temperatures for n‐type and p‐type Bi2Te3‐based ZM ingots and polycrystals are discussed in the perspective of defects engineering. This review can provide the guidance to improve the TE properties of Bi2Te3‐based materials at different temperatures by defects engineering.

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Synergistic modulation of mobility and thermal conductivity in (Bi,Sb)₂Te₃ towards high thermoelectric performance

Abstract: Two-step sintering efficiently enhances zT by tuning the microstructure in a wide range from atomic defects to micrometer second phase.

Cited by 131 publications

References 30 publications

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

Promising and Eco‐Friendly Cu₂X‐Based Thermoelectric Materials: Progress and Applications

Tuning Optimum Temperature Range of Bi₂Te₃‐Based Thermoelectric Materials by Defect Engineering

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Synergistic modulation of mobility and thermal conductivity in (Bi,Sb)2Te3 towards high thermoelectric performance

Abstract: Two-step sintering efficiently enhances zT by tuning the microstructure in a wide range from atomic defects to micrometer second phase.

Cited by 131 publications

References 30 publications

Are Cu2Te‐Based Compounds Excellent Thermoelectric Materials?

Are Cu2Te‐Based Compounds Excellent Thermoelectric Materials?

Promising and Eco‐Friendly Cu2X‐Based Thermoelectric Materials: Progress and Applications

Tuning Optimum Temperature Range of Bi2Te3‐Based Thermoelectric Materials by Defect Engineering

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Product

Resources

About

Synergistic modulation of mobility and thermal conductivity in (Bi,Sb)₂Te₃ towards high thermoelectric performance

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

Are Cu₂Te‐Based Compounds Excellent Thermoelectric Materials?

Promising and Eco‐Friendly Cu₂X‐Based Thermoelectric Materials: Progress and Applications

Tuning Optimum Temperature Range of Bi₂Te₃‐Based Thermoelectric Materials by Defect Engineering