scholarly journals Te Nanoneedles Induced Entanglement and Thermoelectric Improvement of SnSe

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2523 ◽  
Author(s):  
Hyun Ju ◽  
Myeongjin Kim ◽  
Jinglei Yang ◽  
Jooheon Kim
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Phonon Scattering ◽  
Reaction Times ◽  
Base Material ◽  
Thermoelectric Performance ◽  
Optimum Conditions ◽  
Tin Selenide ◽  
Research Fields ◽  
Widespread Interest

Chalcogenide-based materials have attracted widespread interest in high-performance thermoelectric research fields. A strategy for the application of two types of chalcogenide for improved thermoelectric performance is described herein. Tin selenide (SnSe) is used as a base material, and Te nanoneedles are crystallized in the SnSe, resulting in the generation of a composite structure of SnSe with Te nanoneedles. The thermoelectric properties with various reaction times are investigated to reveal the optimum conditions for enhanced thermoelectric performance. A reaction time of 4 h at 450 K generated a composite Te nanoneedles/SnSe sample with the maximum ZT value, 3.2 times larger than that of the pristine SnSe. This result is attributed to both the reduced thermal conductivity from the effective phonon scattering of heterointerfaces and the improved electrical conductivity value due to the introduction of Te nanoparticles. This strategy suggests an approach to generating high-performance practical thermoelectric materials.

Syntheses of Ni-doped and Fe-doped CoSb3 Thermoelectric Nanoparticles through Modified Polyol Process

2009 ◽  
Vol 1166 ◽  
Author(s):  
Takashi Itoh ◽  
Keisuke Isogai
Keyword(s):  
Thermal Conductivity ◽  
Reaction Time ◽  
Phonon Scattering ◽  
Reaction Times ◽  
Lattice Parameter ◽  
Polyol Process ◽  
Thermoelectric Performance ◽  
Partial Substitution ◽  
Reaction Products ◽  
X Ray

AbstractSkutterudite CoSb3 compounds are of increasing interest as materials with good thermoelectric performance over the temperature range of 600 to 800 K, but the thermal conductivity of the materials is relatively high. Nanostructured materials have been shown to enhance phonon scattering and lower the thermal conductivity of the thermoelectric materials. Partial substitution of Ni or Fe on the Co site of CoSb3 is a hopeful route for improving thermoelectric performance of the CoSb3 compounds. In the present work, synthesis of Ni-doped and Fe-doped CoSb3 nanoparticles through the modified polyol process was attempted and the optimum synthesizing condition was investigated. Co(OOCH3)2·4H2O, Ni(OOCH3)2·4H2O, FeCl3·6H2O and SbCl3, were prepared as precursors. The precursors were reduced by NaBH4 in tetraethyleneglycol at 513 K in an argon atmosphere, for different reaction times (holding times). The reaction products were characterized by the X-ray diffraction, the energy dispersive X-ray spectroscopy, and transmission electron microscopy. The nanoparticles with about 20 to 30 nm in size mainly existed in the reaction products regardless of the chemical composition and the reaction time. The skutterudite phase was identified as a main phase in the sample synthesized for long reaction time, but the other phases of Sb and MSb2 (M=Co, Ni, Fe) were also detected. The lattice parameter of the synthesized skutterudite phase linearly increased with increasing the doping agent concentration, following Vegard’s law.

scholarly journals First-principles predictions of low lattice thermal conductivity and high thermoelectric performance of AZnSb (A = Rb, Cs)

RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15486-15496
Author(s):  
Enamul Haque
Keyword(s):  
Thermal Conductivity ◽  
Debye Temperature ◽  
Layered Structure ◽  
First Principles ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Thermoelectric Performance

The layered structure, and presence of heavier elements Rb/Cs and Sb induce high anharmonicity, low Debye temperature, intense phonon scattering, and hence, low lattice thermal conductivity.

scholarly journals Polycrystalline SnSe with a thermoelectric figure of merit greater than the single crystal

2021 ◽  
Author(s):  
Chongjian Zhou ◽  
Yong Kyu Lee ◽  
Yuan Yu ◽  
Sejin Byun ◽  
Zhong-Zhen Luo ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Single Crystal ◽  
High Performance ◽  
Figure Of Merit ◽  
Waste Heat ◽  
Electric Energy ◽  
Cost Effective ◽  
Tin Selenide ◽  
Tin Oxides ◽  
Thermally Conductive

AbstractThermoelectric materials generate electric energy from waste heat, with conversion efficiency governed by the dimensionless figure of merit, ZT. Single-crystal tin selenide (SnSe) was discovered to exhibit a high ZT of roughly 2.2–2.6 at 913 K, but more practical and deployable polycrystal versions of the same compound suffer from much poorer overall ZT, thereby thwarting prospects for cost-effective lead-free thermoelectrics. The poor polycrystal bulk performance is attributed to traces of tin oxides covering the surface of SnSe powders, which increases thermal conductivity, reduces electrical conductivity and thereby reduces ZT. Here, we report that hole-doped SnSe polycrystalline samples with reagents carefully purified and tin oxides removed exhibit an ZT of roughly 3.1 at 783 K. Its lattice thermal conductivity is ultralow at roughly 0.07 W m–1 K–1 at 783 K, lower than the single crystals. The path to ultrahigh thermoelectric performance in polycrystalline samples is the proper removal of the deleterious thermally conductive oxides from the surface of SnSe grains. These results could open an era of high-performance practical thermoelectrics from this high-performance material.

Preferential phonon scattering and low energy carrier filtering by interfaces of in situ formed InSb nanoprecipitates and GaSb nanoinclusions for enhanced thermoelectric performance of In0.2Co4Sb12

2020 ◽  
Vol 49 (44) ◽  
pp. 15883-15894
Author(s):  
Sanyukta Ghosh ◽  
Gyan Shankar ◽  
Anirudha Karati ◽  
Gerda Rogl ◽  
Peter Rogl ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Energy Carrier ◽  
Low Energy ◽  
Thermoelectric Performance

The dispersion of GaSb and InSb nanoinclusions in In-filled Co4Sb12 results in low lattice thermal conductivity and high thermoelectric performance.

Retarding Ostwald ripening through Gibbs adsorption and interfacial complexions leads to high-performance SnTe thermoelectrics

2021 ◽  
Author(s):  
Decheng An ◽  
Jiangjing Wang ◽  
Jie Zhang ◽  
Xin Zhai ◽  
Zepeng Kang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Ostwald Ripening ◽  
Temperature Gradients ◽  
Thermoelectric Performance ◽  
Routine Method ◽  
Long Duration

Nanoprecipitation is a routine method to decrease the thermal conductivity for advancing thermoelectric performance. However, the coarsening/Ostwald ripening of precipitates under temperature gradients in long-duration service deteriorates the efficacy of...

High-performance electron-doped GeMnTe2: hierarchical structure and low thermal conductivity

2019 ◽  
Vol 7 (48) ◽  
pp. 27361-27366 ◽  
Author(s):  
Jinfeng Dong ◽  
Jun Pei ◽  
Hua-Lu Zhuang ◽  
Haihua Hu ◽  
Bowen Cai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Hierarchical Structure ◽  
High Performance ◽  
Thermoelectric Performance ◽  
Low Thermal Conductivity

All scale hierarchical structure induced low thermal conductivity promises high thermoelectric performance of electron doped GeMnTe2.

Fundamental Magnesium Researches in Japan

2005 ◽  
Vol 488-489 ◽  
pp. 9-16 ◽  
Author(s):  
Yo Kojima ◽  
Shigeharu Kamado
Keyword(s):  
Research And Development ◽  
Magnesium Alloys ◽  
High Performance ◽  
Large Scale ◽  
Mechanical Performance ◽  
Science And Technology ◽  
Base Material ◽  
Joint Research ◽  
Practical Utilization ◽  
Research Fields

In the current four-year term project in Japan, new platform science and technology is proposed as a core concept of research and development of advanced magnesium alloys together with understanding of their intrinsic characteristics. The research fields related to advanced super-light magnesium alloys for 21st Century have been focused to the selected three categories; ecomaterial design and processing, high qualification of mechanical performance, and high performance design and processing in functionality. On the basis of the obtained results, platform science and technology for environmentally benign and high performance magnesium alloys is constructed as an industrial base material for the next generation. As a result, numerous large-scale joint research and development projects on magnesium alloys based on partnerships between industries, academia and government has already started towards practical utilization since last year.

scholarly journals Enhanced thermoelectric performance of polycrystalline SnSe by compositing with layered Ti3C2Tx

2021 ◽  
Author(s):  
Yi Qin ◽  
Xiaohan Li ◽  
Ting Zhao ◽  
Jianfeng Zhu ◽  
Yanling Yang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Self Assembly ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
Seebeck Coefficients ◽  
Nanostructured Composite ◽  
Assembly Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Density Interfaces

Abstract Thermoelectric materials convert thermal energy into electricity directly. Constructing nanostructured composite architectures can be an effective strategy to develop thermoelectric performance. SnSe/Ti3C2Tx composite materials were synthesized through the electrostatic self-assembly method followed by spark plasma sintering. The interfaces introduced by Ti3C2Tx can scatter carriers effectively, thus increasing the Seebeck coefficients (S), finally, a high absolute S value of ~ 296.2 µV K− 1 was obtained at 773 K. At the same time, the high-density interfaces of SnSe/Ti3C2Tx composites enhance the phonon scattering, a low lattice thermal conductivity klat of 0.54 W m− 1 K− 1 was obtained in sample ω = 0.1%. Benefit from the elevated Seebeck coefficient and decreased thermal conductivity, a ZT of 0.1 was obtained in sample ω = 0.1% at 773 K along the pressing direction, compared with the pure SnSe, the thermoelectric performance improved by 68%. This research will provide a new way for the development of the thermoelectric properties of polycrystalline SnSe.

scholarly journals Giant isotope effect on phonon dispersion and thermal conductivity in methylammonium lead iodide

2020 ◽  
Vol 6 (31) ◽  
pp. eaaz1842
Author(s):  
M. E. Manley ◽  
K. Hong ◽  
P. Yin ◽  
S. Chi ◽  
Y. Cai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Phonon Scattering ◽  
Light Emission ◽  
Phonon Dispersion ◽  
Acoustic Phonons ◽  
Lead Iodide ◽  
Phonon Bottleneck ◽  
Optic Phonon ◽  
Methylammonium Lead Iodide

Lead halide perovskites are strong candidates for high-performance low-cost photovoltaics, light emission, and detection applications. A hot-phonon bottleneck effect significantly extends the cooling time of hot charge carriers, which thermalize through carrier–optic phonon scattering, followed by optic phonon decay to acoustic phonons and finally thermal conduction. To understand these processes, we adjust the lattice dynamics independently of electronics by changing isotopes. We show that doubling the mass of hydrogen in methylammonium lead iodide by replacing protons with deuterons causes a large 20 to 50% softening of the longitudinal acoustic phonons near zone boundaries, reduces thermal conductivity by ~50%, and slows carrier relaxation kinetics. Phonon softening is attributed to anticrossing with the slowed libration modes of the deuterated molecules and the reduced thermal conductivity to lowered phonon velocities. Our results reveal how tuning the organic molecule dynamics enables control of phonons important to thermal conductivity and the hot-phonon bottleneck.

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