scholarly journals Substantial thermoelectric enhancement achieved by manipulating the band structure and dislocations in Ag and La co-doped SnTe

2021 ◽  
Author(s):  
Wenjing Xu ◽  
Zhongwei Zhang ◽  
Chengyan Liu ◽  
Jie Gao ◽  
Zhenyuan Ye ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Power Factor ◽  
Figure Of Merit ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Electronic Band ◽  
Co Doping ◽  
High Carrier ◽  
Valence Bands

AbstractEco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe; yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration and high thermal conductivity. In this work, we confirm that the Ag and La co-doping can be applied to simultaneously enhance the power factor and reduce the thermal conductivity, contributing to a final promotion of figure of merit. On one hand, the carrier concentration and band offset between valence bands are concurrently reduced, promoting the power factor to a highest value of ∼2436 µW·m−1·K−2 at 873 K. On the other hand, lots of dislocations (∼3.16×107 mm−2) associated with impurity precipitates are generated, resulting in the decline of thermal conductivity to a minimum value of 1.87 W·m−1·K−1 at 873 K. As a result, a substantial thermoelectric performance enhancement up to zT ≈ 1.0 at 873 K is obtained for the sample Sn0.94Ag0.09La0.05Te, which is twice that of the pristine SnTe (zT ≈ 0.49 at 873 K). This strategy of synergistic manipulation of electronic band and microstructures via introducing rare earth elements could be applied to other systems to improve thermoelectric performance.

scholarly journals Macroscopic weavable fibers of carbon nanotubes with giant thermoelectric power factor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver S. Dewey ◽  
Lauren W. Taylor ◽  
Mitchell A. Trafford ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Fermi Energy ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Thermoelectric Power Factor ◽  
Large Power ◽  
Energy Tuning

AbstractLow-dimensional materials have recently attracted much interest as thermoelectric materials because of their charge carrier confinement leading to thermoelectric performance enhancement. Carbon nanotubes are promising candidates because of their one-dimensionality in addition to their unique advantages such as flexibility and light weight. However, preserving the large power factor of individual carbon nanotubes in macroscopic assemblies has been challenging, primarily due to poor sample morphology and a lack of proper Fermi energy tuning. Here, we report an ultrahigh value of power factor (14 ± 5 mW m−1 K−2) for macroscopic weavable fibers of aligned carbon nanotubes with ultrahigh electrical and thermal conductivity. The observed giant power factor originates from the ultrahigh electrical conductivity achieved through excellent sample morphology, combined with an enhanced Seebeck coefficient through Fermi energy tuning. We fabricate a textile thermoelectric generator based on these carbon nanotube fibers, which demonstrates high thermoelectric performance, weavability, and scalability. The giant power factor we observe make these fibers strong candidates for the emerging field of thermoelectric active cooling, which requires a large thermoelectric power factor and a large thermal conductivity at the same time.

Synergistic optimization of carrier transport and thermal conductivity in Sn-doped Cu2Te

2018 ◽  
Vol 6 (39) ◽  
pp. 18928-18937 ◽  
Author(s):  
Yuchong Qiu ◽  
Ying Liu ◽  
Jinwen Ye ◽  
Jun Li ◽  
Lixian Lian
Keyword(s):  
Thermal Conductivity ◽  
Fermi Level ◽  
Carrier Concentration ◽  
Power Factor ◽  
Carrier Transport ◽  
Lone Pair ◽  
Thermoelectric Performance ◽  
Degenerate Semiconductors ◽  
Lone Pair Electrons

Doping Sn into the Cu2Te lattice can synergistically enhance the power factor and decrease thermal conductivity, leading to remarkably optimized zTs. The lone pair electrons from the 5s orbital of Sn can increase the DOS near the Fermi level of Cu2Te to promote PF and reduce κe by decreasing the carrier concentration. This study explores a scalable strategy to optimize the thermoelectric performance for intrinsically highly degenerate semiconductors.

scholarly journals Analyzing transport properties of p-type Mg2Si–Mg2Sn solid solutions: optimization of thermoelectric performance and insight into the electronic band structure

2019 ◽  
Vol 7 (3) ◽  
pp. 1045-1054 ◽  
Author(s):  
Hasbuna Kamila ◽  
Prashant Sahu ◽  
Aryan Sankhla ◽  
Mohammad Yasseri ◽  
Hoang-Ngan Pham ◽  
...  
Keyword(s):  
Band Structure ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Electronic Band Structure ◽  
Thermoelectric Performance ◽  
Electronic Band ◽  
P Type ◽  
Insight Into

Figure of merit zT mapping of p-Mg2Si1−xSnx with respect to carrier concentration.

Thermoelectric performance enhancement of Cu2S by Se doping leading to a simultaneous power factor increase and thermal conductivity reduction

2017 ◽  
Vol 5 (31) ◽  
pp. 7845-7852 ◽  
Author(s):  
Yao Yao ◽  
Bo-Ping Zhang ◽  
Jun Pei ◽  
Yao-Chun Liu ◽  
Jing-Feng Li
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Alloying ◽  
Spark Plasma Sintering ◽  
Power Factor ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Plasma Sintering ◽  
Se Doping ◽  
Spark Plasma

A series of single-phased Cu2S1−xSex bulks were prepared by using mechanical alloying (MA) combined with spark plasma sintering (SPS). Our results suggest that the TE properties of Cu2S can be greatly enhanced by simultaneously increasing PF and decreasing κ via doping a sole Se element.

scholarly journals Centimeter-Long Weavable Fibers of Carbon Nanotubes with Giant Thermoelectric Power Factor

2021 ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver Dewey ◽  
Lauren Taylor ◽  
Mitchell Trafford ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Fermi Energy ◽  
Performance Enhancement ◽  
Thermoelectric Performance ◽  
Thermoelectric Power Factor ◽  
Electronic Density ◽  
Large Power

Abstract Low-dimensional materials have recently attracted much interest as thermoelectric materials because of their charge carrier confinement leading to thermoelectric performance enhancement. Carbon nanotubes are promising candidates because of their one-dimensionality in addition to their unique advantages such as flexibility and light weight. However, preserving the large power factor of individual carbon nanotubes in macroscopic assemblies has been challenging, primarily due to poor sample morphology and a lack of proper Fermi energy tuning. Here, we report an unprecedentedly high value of power factor (14±5 mWm-1K-2) for centimeter-long weavable fibers of aligned carbon nanotubes with ultrahigh electrical and thermal conductivity. Our theoretical simulations show that the observed giant power factor originates from the one-dimensional quantum confinement of charge carriers, appearing when the Fermi energy is near a van Hove singularity in the electronic density of states. We fabricated a textile thermoelectric generator based on these carbon nanotube fibers, which demonstrated high thermoelectric performance, weavablity, and scalability. The giant power factor we observed make these fibers strong candidates for the emerging field of thermoelectric active cooling, which requires a large thermoelectric power factor and a large thermal conductivity at the same time.

The study of structural, electronic and thermoelectric properties of Ca1−xYbxZn2Sb2 (x = 0, 0.25, 0.5, 0.75, 1) Zintl compounds

2021 ◽  
pp. 2150100
Author(s):  
I. Mili ◽  
H. Latelli ◽  
T. Ghellab ◽  
Z. Charifi ◽  
H. Baaziz ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Figure Of Merit ◽  
Narrow Gap ◽  
High Carrier Concentration ◽  
Merit Factor ◽  
Composition Formula ◽  
High Seebeck Coefficient ◽  
High Carrier

Based on the electronic structure, the physical properties of [Formula: see text] ([Formula: see text], 0.25, 0.5, 0.75, 1) Zintl compounds are studied. The transport properties can be significantly changed by varying the composition [Formula: see text]. The materials under study are more metallic with increasing [Formula: see text] and behaves like a semiconductor when [Formula: see text] decreases. It is found that [Formula: see text] exhibits a larger thermopower magnitude ([Formula: see text] at [Formula: see text] and the Seebeck coefficient decreases as [Formula: see text] increases. The calculated figure of merit factor of [Formula: see text] is found to be low, this is explained by the fact that its structure is very compact and its bandgap is small which lead to high electrical and thermal conductivity due to high carrier concentration ([Formula: see text] at [Formula: see text]). On other hand a narrow-gap (0.46 eV for [Formula: see text]), provides a balance between a high Seebeck coefficient and low electronic thermal conductivity, with a slight increase in the carrier concentration when the temperature increases ([Formula: see text] at 600 K). As a consequence, [Formula: see text] compound is predicted to have good performance for thermoelectric applications. The electrical [Formula: see text] and the thermal [Formula: see text] conductivity for [Formula: see text] compound in both directions (along [Formula: see text] and [Formula: see text]-axes) are calculated. It is obtained that [Formula: see text] is 120% of [Formula: see text] at high-temperature, whereas [Formula: see text] Seebeck coefficient was higher than [Formula: see text] especially at [Formula: see text] ([Formula: see text]. The large value of [Formula: see text] showed that the transport is dominated by zz-axis.

Enhanced thermoelectric performance through carrier scattering at heterojunction potentials in BiSbTe based composites with Cu3SbSe4 nanoinclusions

2015 ◽  
Vol 3 (27) ◽  
pp. 7045-7052 ◽  
Author(s):  
Yuanyue Li ◽  
Di Li ◽  
Xiaoying Qin ◽  
Xiuhui Yang ◽  
Yongfei Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Thermoelectric Performance ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Carrier Scattering ◽  
Interface Scattering

Owing to enhanced power factor and reduced lattice thermal conductivity through interface scattering, a largest thermoelectric figure of merit ZT = 1.61 is achieved at 467 K for BiSbTe based composite with Cu3SbSe4 nanoinclusions.

scholarly journals Improving the Thermoelectric Properties of the Half-Heusler Compound VCoSb by Vanadium Vacancy

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1637 ◽  
Author(s):  
Lihong Huang ◽  
Junchen Wang ◽  
Xiaobo Mo ◽  
Xiaobo Lei ◽  
Sude Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Seebeck Coefficient ◽  
Carrier Concentration ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Secondary Phase ◽  
Thermoelectric Performance ◽  
Heusler Compound

The effects of V vacancy on the thermoelectric performance of the half-Heusler compound VCoSb have been investigated in this study. A certain amount of CoSb secondary phase is generated in the VCoSb matrix when the content of V vacancy is more than 0.1 at%. According to the results, a ZT value of 0.6, together with a power factor of 29 μW cm−1 K−2 at 873 K, were achieved for the nonstoichiometric sample V0.9CoSb. This proved that moderate V vacancy could improve the thermoelectric (TE) properties of VCoSb. The noticeable improvements are mainly owing to the incremental Seebeck coefficient, which may benefit from the optimized carrier concentration. However, too much V vacancy will result in more CoSb impurity and deteriorate the TE performances of VCoSb owing to the increased thermal conductivity.

High thermoelectric performance of superionic argyrodite compound Ag8SnSe6

2016 ◽  
Vol 4 (24) ◽  
pp. 5806-5813 ◽  
Author(s):  
Lin Li ◽  
Yuan Liu ◽  
Jiyan Dai ◽  
Aijun Hong ◽  
Min Zeng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Material ◽  
Power Factor ◽  
High Power ◽  
Figure Of Merit ◽  
Environmentally Friendly ◽  
Thermoelectric Performance ◽  
Low Thermal Conductivity ◽  
High Power Factor ◽  
High Figure

A good thermoelectric material usually has a high power factor and low thermal conductivity for high figure of merit (ZT), and is also environmentally friendly and economical.

Enhanced figure of merit in Mg2Si0.877Ge0.1Bi0.023/multi wall carbon nanotube nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (80) ◽  
pp. 65328-65336 ◽  
Author(s):  
Nader Farahi ◽  
Sagar Prabhudev ◽  
Matthieu Bugnet ◽  
Gianluigi A. Botton ◽  
Jianbao Zhao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Power Factor ◽  
Figure Of Merit ◽  
Phonon Scattering ◽  
Thermoelectric Performance ◽  
Multi Wall Carbon Nanotubes ◽  
Energy Filtering ◽  
Multi Wall Carbon Nanotube

Adding multi wall carbon nanotubes to Mg2Si0.877Ge0.1Bi0.023 led to an increased power factor via energy filtering as well as a lowered thermal conductivity via increased phonon scattering, and thus an enhanced thermoelectric performance.

Sign in / Sign up

Export Citation Format

Share Document