Enhanced thermoelectric performance of band structure engineered GeSe1−xTex alloys

2021 ◽  
Vol 5 (6) ◽  
pp. 1734-1746
Author(s):  
D. Sidharth ◽  
A. S. Alagar Nedunchezhian ◽  
R. Akilan ◽  
Anup Srivastava ◽  
Bhuvanesh Srinivasan ◽  
...  

The power factor of GeSe enhanced and thermal conductivity decreased by Te substitution and thereby, GeSe0.80Te0.20 exhibits high ZT.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver S. Dewey ◽  
Lauren W. Taylor ◽  
Mitchell A. Trafford ◽  
...  

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.


2018 ◽  
Vol 6 (39) ◽  
pp. 18928-18937 ◽  
Author(s):  
Yuchong Qiu ◽  
Ying Liu ◽  
Jinwen Ye ◽  
Jun Li ◽  
Lixian Lian

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.


2021 ◽  
Vol 871 ◽  
pp. 203-207
Author(s):  
Jian Liu

In this work, we use first principles DFT calculations, anharmonic phonon scatter theory and Boltzmann transport method, to predict a comprehensive study on the thermoelectric properties as electronic and phonon transport of layered LaSe2 crystal. The flat-and-dispersive type band structure of LaSe2 crystal offers a high power factor. In the other hand, low lattice thermal conductivity is revealed in LaSe2 semiconductor, combined with its high power factor, the LaSe2 crystal is considered a promising thermoelectric material. It is demonstrated that p-type LaSe2 could be optimized to exhibit outstanding thermoelectric performance with a maximum ZT value of 1.41 at 1100K. Explored by density functional theory calculations, the high ZT value is due to its high Seebeck coefficient S, high electrical conductivity, and low lattice thermal conductivity .


2017 ◽  
Vol 5 (31) ◽  
pp. 7845-7852 ◽  
Author(s):  
Yao Yao ◽  
Bo-Ping Zhang ◽  
Jun Pei ◽  
Yao-Chun Liu ◽  
Jing-Feng Li

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.


2021 ◽  
Author(s):  
Natsumi Komatsu ◽  
Yota Ichinose ◽  
Oliver Dewey ◽  
Lauren Taylor ◽  
Mitchell Trafford ◽  
...  

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.


2016 ◽  
Vol 45 (17) ◽  
pp. 7483-7491 ◽  
Author(s):  
Heng Quan Yang ◽  
Lei Miao ◽  
Cheng Yan Liu ◽  
Xiao Yang Wang ◽  
Ying Peng ◽  
...  

Wire-like SnxSb2Te3+x (x = 0.00–0.05) nanoparticles were synthesized using elemental precursors in EG. An enhanced power factor and reduced thermal conductivity were realized in the Sn0.02Sb2Te3.02 nanobulk sample as a result of the newly generated defect centers of (Sn′Sb + h˙).


2015 ◽  
Vol 3 (27) ◽  
pp. 7045-7052 ◽  
Author(s):  
Yuanyue Li ◽  
Di Li ◽  
Xiaoying Qin ◽  
Xiuhui Yang ◽  
Yongfei Liu ◽  
...  

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.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1637 ◽  
Author(s):  
Lihong Huang ◽  
Junchen Wang ◽  
Xiaobo Mo ◽  
Xiaobo Lei ◽  
Sude Ma ◽  
...  

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.


2018 ◽  
Vol 6 (2) ◽  
pp. 349-356 ◽  
Author(s):  
Jiwon Kim ◽  
Kyu Hyoung Lee ◽  
Sung-Dae Kim ◽  
Jae-Hong Lim ◽  
Nosang V. Myung

The embedding of nanoprecipitates into a semiconducting matrix can lead to improved thermoelectric performances by enhancing the power factor or reducing the thermal conductivity of the system in which they are incorporated.


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