| 1. |
- Jia, Yanhua, et al.
(author)
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Wearable Thermoelectric Materials and Devices for Self-Powered Electronic Systems
- 2021
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In: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095. ; 33:42
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Research review (peer-reviewed)abstract
- The emergence of artificial intelligence and the Internet of Things has led to a growing demand for wearable and maintenance-free power sources. The continual push toward lower operating voltages and power consumption in modern integrated circuits has made the development of devices powered by body heat finally feasible. In this context, thermoelectric (TE) materials have emerged as promising candidates for the effective conversion of body heat into electricity to power wearable devices without being limited by environmental conditions. Driven by rapid advances in processing technology and the performance of TE materials over the past two decades, wearable thermoelectric generators (WTEGs) have gradually become more flexible and stretchable so that they can be used on complex and dynamic surfaces. In this review, the functional materials, processing techniques, and strategies for the device design of different types of WTEGs are comprehensively covered. Wearable self-powered systems based on WTEGs are summarized, including multi-function TE modules, hybrid energy harvesting, and all-in-one energy devices. Challenges in organic TE materials, interfacial engineering, and assessments of device performance are discussed, and suggestions for future developments in the area are provided. This review will promote the rapid implementation of wearable TE materials and devices in self-powered electronic systems.
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| 2. |
- Sadowski, Grzegorz, et al.
(author)
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Epitaxial growth and thermoelectric properties of Mg3Bi2 thin films deposited by magnetron sputtering
- 2022
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 120:5
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Journal article (peer-reviewed)abstract
- Mg3Sb2-based thermoelectric materials attract attention for applications near room temperature. Here, Mg-Bi films were synthesized using magnetron sputtering at deposition temperatures from room temperature to 400 & DEG;C. Single-phase Mg3Bi2 thin films were grown on c-plane-oriented sapphire and Si(100) substrates at a low deposition temperature of 200 & DEG;C. The Mg3Bi2 films grew epitaxially on c-sapphire and fiber-textured on Si(100). The orientation relationships for the Mg3Bi2 film with respect to the c-sapphire substrate are (0001) Mg3Bi2||(0001) Al2O3 and [11 2 over bar 0] Mg3Bi2||[11 2 over bar 0] Al2O3. The observed epitaxy is consistent with the relatively high work of separation, calculated by the density functional theory, of 6.92 J m(-2) for the Mg3Bi2 (0001)/Al2O3 (0001) interface. Mg3Bi2 films exhibited an in-plane electrical resistivity of 34 mu omega m and a Seebeck coefficient of +82.5 mu V K-1, yielding a thermoelectric power factor of 200 mu W m(-1) K-2 near room temperature.
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| 3. |
- Sadowski, Grzegorz, et al.
(author)
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Structural evolution and thermoelectric properties of Mg3SbxBi2-x thin films deposited by magnetron sputtering
- 2023
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In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : A V S AMER INST PHYSICS. - 0734-2101 .- 1520-8559. ; 41:4
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Journal article (peer-reviewed)abstract
- Mg3Bi2-based compounds are of great interest for thermoelectric applications near room temperature. Here, undoped p-type Mg3SbxBi2-x thin films were synthesized using magnetron sputtering (three elemental targets in Ar atmosphere) with a growth temperature of 200 ? on three different substrates, namely, Si as well as c- and r-sapphire. The elemental composition was measured with energy-dispersive x-ray spectroscopy and the structure by x-ray diffraction. The electrical resistivity and the Seebeck coefficient were determined under He atmosphere from room temperature to the growth temperature. All samples are crystalline exhibiting the La2O3-type crystal structure (space group P-3m1). The observed thermoelectric response is consistent with a semiconductive behavior. With increasing x, the samples become more electrically resistive due to the increasing bandgap. High Bi content (x < 1) is thus beneficial due to lower resistivity and a higher power factor near room temperature. Thermoelectric thin films synthesized at low temperatures may provide novel pathways to enable flexible devices on polymeric and other heat-sensitive substrates.
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| 4. |
- Shu, Rui, et al.
(author)
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Solid-State Janus Nanoprecipitation Enables Amorphous-Like Heat Conduction in Crystalline Mg3Sb2-Based Thermoelectric Materials
- 2022
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In: Advanced Science. - : Wiley. - 2198-3844. ; 9:25
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Journal article (peer-reviewed)abstract
- Solid-state precipitation can be used to tailor material properties, ranging from ferromagnets and catalysts to mechanical strengthening and energy storage. Thermoelectric properties can be modified by precipitation to enhance phonon scattering while retaining charge-carrier transmission. Here, unconventional Janus-type nanoprecipitates are uncovered in Mg3Sb1.5Bi0.5 formed by side-by-side Bi- and Ge-rich appendages, in contrast to separate nanoprecipitate formation. These Janus nanoprecipitates result from local comelting of Bi and Ge during sintering, enabling an amorphous-like lattice thermal conductivity. A precipitate size effect on phonon scattering is observed due to the balance between alloy-disorder and nanoprecipitate scattering. The thermoelectric figure-of-merit ZT reaches 0.6 near room temperature and 1.6 at 773 K. The Janus nanoprecipitation can be introduced into other materials and may act as a general property-tailoring mechanism.
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| 5. |
- Wang, Weishu, et al.
(author)
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滑行过程中火箭发动机泵系统各构件温度数值模拟
- 2005
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In: Journal of Propulsion Technology. - Beijing, China. - 1001-4055. ; 26, s. 394-397
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Journal article (peer-reviewed)abstract
- 利用数值计算的方法,研究了某型液体火箭发动机泵系统各构件及泵腔残余氧化剂在二次启动前滑行过程的温度变化。基于集总参数法建立了温度变化计算模型,并建立了泵腔残余氧化剂排空计算模型。计算结果与试车数据吻合良好。滑行过程中,涡轮温度下降,而泵壳体及进口管的温度升高;泵腔中残余氧化剂间歇排放。研究结果表明,滑行结束时泵系统的温度高于100℃,泵腔中残余氧化剂含汽率为1,不满足二次点火启动条件。
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| 6. |
- Zhu, Yongbin, et al.
(author)
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Enhanced Thermoelectric Properties of Mg2Sn-Mg3Sb2 Nanocomposites by Tailoring Matrix/Inclusion Interface toward Energy Harvesting Applications
- 2023
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In: ACS Applied Nano Materials. - : AMER CHEMICAL SOC. - 2574-0970. ; 6:7, s. 6133-6140
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Journal article (peer-reviewed)abstract
- Nanocomposites have been long exploited for achieving balanced material properties. Here, we synthesized nominal (Mg2Sn0.85Sb0.15)1-x-(Mg3Sb2)x (x = 0-0.15) nano-composites, achieving a significant reduction of the lattice thermal conductivity of Mg2Sn0.85Sb0.15 from 2.03 Wm-1K-1 to 1.38 Wm-1K-1 due to phonon scattering by VMg point defects, Mg3Sb2 nanoparticles, and heterogeneous interfaces. Hence, a significantly enhanced thermoelectric figure of merit, ZT, is achieved. At 773 K, the sample of x = 0.075 reaches a ZT of 1.4, corresponding to a 14% enhancement compared to the Mg2Sn0.85Sb0.15 (x = 0) sample. The strategy of introducing heterogeneous structures has important implications for reducing thermal conductivity for other solid-solution thermoelectric systems.
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