scholarly journals N-Type Mg3Sb2-xBix Alloys as Promising Thermoelectric Materials

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Hongjing Shang ◽  
Zhongxin Liang ◽  
Congcong Xu ◽  
Jun Mao ◽  
Hongwei Gu ◽  
...  
Keyword(s):  
Thermoelectric Materials ◽  
Waste Heat Recovery ◽  
Carrier Mobility ◽  
Figure Of Merit ◽  
Waste Heat ◽  
Impurity Scattering ◽  
Thermoelectric Figure ◽  
Carrier Scattering ◽  
Ionized Impurity Scattering ◽  
Extrinsic Defects

N-type Mg3Sb2-xBix alloys have been extensively studied in recent years due to their significantly enhanced thermoelectric figure of merit (zT), thus promoting them as potential candidates for waste heat recovery and cooling applications. In this review, the effects resulting from alloying Mg3Bi2 with Mg3Sb2, including narrowed bandgap, decreased effective mass, and increased carrier mobility, are summarized. Subsequently, defect-controlled electrical properties in n-type Mg3Sb2-xBix are revealed. On one hand, manipulation of intrinsic and extrinsic defects can achieve optimal carrier concentration. On the other hand, Mg vacancies dominate carrier-scattering mechanisms (ionized impurity scattering and grain boundary scattering). Both aspects are discussed for Mg3Sb2-xBix thermoelectric materials. Finally, we review the present status of, and future outlook for, these materials in power generation and cooling applications.

scholarly journals Manipulation of ionized impurity scattering for achieving high thermoelectric performance in n-type Mg3Sb2-based materials

2017 ◽  
Vol 114 (40) ◽  
pp. 10548-10553 ◽  
Author(s):  
Jun Mao ◽  
Jing Shuai ◽  
Shaowei Song ◽  
Yixuan Wu ◽  
Rebecca Dally ◽  
...  
Keyword(s):  
Power Factor ◽  
Carrier Mobility ◽  
Phonon Scattering ◽  
Impurity Scattering ◽  
Substantial Improvement ◽  
Thermoelectric Performance ◽  
Scattering Mechanism ◽  
Carrier Scattering ◽  
Ionized Impurity Scattering ◽  
Higher Carrier Mobility

Achieving higher carrier mobility plays a pivotal role for obtaining potentially high thermoelectric performance. In principle, the carrier mobility is governed by the band structure as well as by the carrier scattering mechanism. Here, we demonstrate that by manipulating the carrier scattering mechanism in n-type Mg3Sb2-based materials, a substantial improvement in carrier mobility, and hence the power factor, can be achieved. In this work, Fe, Co, Hf, and Ta are doped on the Mg site of Mg3.2Sb1.5Bi0.49Te0.01, where the ionized impurity scattering crosses over to mixed ionized impurity and acoustic phonon scattering. A significant improvement in Hall mobility from ∼16 to ∼81 cm2⋅V−1⋅s−1 is obtained, thus leading to a notably enhanced power factor of ∼13 μW⋅cm−1⋅K−2 from ∼5 μW⋅cm−1⋅K−2. A simultaneous reduction in thermal conductivity is also achieved. Collectively, a figure of merit (ZT) of ∼1.7 is obtained at 773 K in Mg3.1Co0.1Sb1.5Bi0.49Te0.01. The concept of manipulating the carrier scattering mechanism to improve the mobility should also be applicable to other material systems.

scholarly journals Hybrid-structured ZnO thermoelectric materials with high carrier mobility and reduced thermal conductivity

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10855-10864 ◽  
Author(s):  
Dai-Bing Zhang ◽  
He-Zhang Li ◽  
Bo-Ping Zhang ◽  
Dou-dou Liang ◽  
Min Xia
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Materials ◽  
Carrier Mobility ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Carrier Mobility ◽  
High Carrier

We obtained a high thermoelectric figure of merit (ZT) in this simple ZnO by adopting a hybrid micro/nano structuring approach.

Thermoelectric Properties of n-Type 90% Bi2Te3+10%Bi2Se3 Thermoelectric Materials Produced by Melt Spinning Method and Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 161-164 ◽  
Author(s):  
Taek Soo Kim ◽  
Byong Sun Chun
Keyword(s):  
Solid Solutions ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Melt Spinning ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Thermoelectric Figure Of Merit ◽  
Vacuum Sintering ◽  
Thermoelectric Figure ◽  
Sintering Processes

N-type Bi2Te3-Sb2Te3 solid solutions doped with CdCl2 was prepared by melt spinning, crushing and vacuum sintering processes. Microstructure, bending strength and thermoelectric property were investigated as a function of the doping quantity from 0.03wt.% to 0.10wt.% and sintering temperature from 400oC to 500oC, and finally compared with those of conventionally fabricated alloys. The alloy showed a good structural homogeneity as well as bending strength of 3.88Kgf/mm2. The highest thermoelectric figure of merit was obtained by doping 0.03wt.% and sintering at 500oC.

Materials With Open Crystal Structure as Prospective Novel Thermoelectrics

1998 ◽  
Vol 545 ◽  
Author(s):  
Ctirad Uher ◽  
Jihui Yang ◽  
Siqing Hu
Keyword(s):  
Crystal Structure ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Optimal Transport ◽  
Heusler Alloys ◽  
Thermoelectric Figure Of Merit ◽  
Great Flexibility ◽  
Thermoelectric Figure ◽  
Guest Species ◽  
Filled Skutterudites

AbstractA useful approach to identify materials with high thermoelectric figure of merit is to search for solids that offer great flexibility to modify and tailor the structure so as to achieve the optimal transport behavior. Among the most promising novel thermoelectric materials are solids with “open crystal structure”. They may be typified by structures with unfilled cages, crystals with an empty atomic sublattice, and by a network of polyhedral cages enclosing guest species. In this paper we present our latest results concerning transport properties in the above classes of solids. Specifically, we focus on the filled skutterudites, half-Heusler alloys, and clathrates.

Enhancing the average thermoelectric figure of merit of elemental Te by suppressing grain boundary scattering

2020 ◽  
Vol 8 (17) ◽  
pp. 8455-8461 ◽  
Author(s):  
Yehao Wu ◽  
Feng Liu ◽  
Qi Zhang ◽  
Tiejun Zhu ◽  
Kaiyang Xia ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Grain Boundary ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Boundary Scattering ◽  
Thermoelectric Figure ◽  
Grain Boundary Scattering

Suppressed grain boundary scattering contributes to enhanced electrical conductivity and device zT in elemental Te based thermoelectric materials.

High thermoelectric performance in low-cost SnS0.91Se0.09 crystals

Science ◽  
2019 ◽  
Vol 365 (6460) ◽  
pp. 1418-1424 ◽  
Author(s):  
Wenke He ◽  
Dongyang Wang ◽  
Haijun Wu ◽  
Yu Xiao ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Thermoelectric Materials ◽  
High Performance ◽  
Carrier Mobility ◽  
Figure Of Merit ◽  
Toxic Elements ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Tin Sulfide ◽  
Temperature Dependent ◽  
Earth Abundant

Thermoelectric technology allows conversion between heat and electricity. Many good thermoelectric materials contain rare or toxic elements, so developing low-cost and high-performance thermoelectric materials is warranted. Here, we report the temperature-dependent interplay of three separate electronic bands in hole-doped tin sulfide (SnS) crystals. This behavior leads to synergistic optimization between effective mass (m*) and carrier mobility (μ) and can be boosted through introducing selenium (Se). This enhanced the power factor from ~30 to ~53 microwatts per centimeter per square kelvin (μW cm−1 K−2 at 300 K), while lowering the thermal conductivity after Se alloying. As a result, we obtained a maximum figure of merit ZT (ZTmax) of ~1.6 at 873 K and an average ZT (ZTave) of ~1.25 at 300 to 873 K in SnS0.91Se0.09 crystals. Our strategy for band manipulation offers a different route for optimizing thermoelectric performance. The high-performance SnS crystals represent an important step toward low-cost, Earth-abundant, and environmentally friendly thermoelectrics.

The Effects of the Carrier Concentrations on the Hall Mobilities of ZnO:Al Thin Films Deposited by Magnetron Sputtering

2017 ◽  
Vol 727 ◽  
pp. 938-941
Author(s):  
Xiao Jing Wang ◽  
Yun Zhang
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Magnetron Sputtering ◽  
Carrier Concentration ◽  
Carrier Mobility ◽  
Impurity Scattering ◽  
Flexible Substrates ◽  
Boundary Scattering ◽  
Scattering Mechanism ◽  
Ionized Impurity Scattering

ZnO:Al thin films were deposited on flexible substrates by magnetron sputtering. The effects of the carrier concentrations on the hall mobilities of AZO films were investigated. When the carrier concentration was high (~1020/cm3), the hall mobility decreased with increase of the carrier concentration, showing obvious characteristics of ionized impurity scattering; moreover, the carrier mobility could be expressed to be-2.14/3 proportional of the carrier concentration by combining the results of simulation and experiments.simulation and experiment. When the carrier concentration was about a magnitude of 1019 cm-3, the carrier mobility is influenced by the carrier concentration and grain size, which means the carrier mobility was affected by both the grain boundary scattering and ionized purity scattering mechanism.

Heat Transport in Superlattices and Nanocomposites for Thermoelectric Applications

2006 ◽  
Vol 46 ◽  
pp. 104-110 ◽  
Author(s):  
Gang Chen
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Large Scale ◽  
Energy Transport ◽  
High Efficiency ◽  
Waste Heat ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure

Energy transport in nanostructures differs significantly from macrostructures because of classical and quantum size effects on energy carriers. Experimental results show that the thermal conductivity values of nanostructures such as superlattices are significantly lower than that of their bulk constituent materials. The reduction in thermal conductivity led to a large increase in the thermoelectric figure of merit in several superlattice systems. Materials with a large thermoelectric figure of merit can be used to develop efficient solid-state devices that convert waste heat into electricity. Superlattices grown by thin-film deposition techniques, however, are not suitable for large scale applications. Nanocomposites represent one approach that can lead to high thermoelectric figure merit. This paper reviews the current understanding of thermal conductivity reduction mechanisms in superlattices and presents theoretical studies on thermoelectric properties in semiconducting nanocomposites, aiming at developing high efficiency thermoelectric energy conversion materials.

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