scholarly journals Two impurity energy level regulation leads to enhanced thermoelectric performance of Ag1−xCdxIn5Se8

RSC Advances ◽  
2017 ◽  
Vol 7 (21) ◽  
pp. 12719-12725 ◽  
Author(s):  
Xingchen Shen ◽  
Nusrat Shaheen ◽  
Aijuan Zhang ◽  
Dingfeng Yang ◽  
Wei Yao ◽  
...  

AgIn5Se8 is a promising thermoelectric material due to its low thermal conductivity. By incorporating Cd2+ ions at Ag+ lattice sites; the electron concentration is increased, resulting in greatly enhanced electrical conductivity, and a high thermoelectric power factor.

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.


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 4 (24) ◽  
pp. 5806-5813 ◽  
Author(s):  
Lin Li ◽  
Yuan Liu ◽  
Jiyan Dai ◽  
Aijun Hong ◽  
Min Zeng ◽  
...  

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.


RSC Advances ◽  
2018 ◽  
Vol 8 (37) ◽  
pp. 20764-20772
Author(s):  
Ahmad Gharleghi ◽  
Roy-Hung Hung ◽  
Zong-Ren Yang ◽  
Rasoul Malekfar ◽  
Chia-Jyi Liu

The peak zT is attained for hydrothermally synthesized Bi0.83Zn0.05Sb0.12 nanoalloy due to the significantly enhanced thermoelectric power factor and relatively low thermal conductivity.


2014 ◽  
Vol 2 (30) ◽  
pp. 11913-11921 ◽  
Author(s):  
D. K. Misra ◽  
A. Bhardwaj ◽  
Sanjay Singh

Varying the valence electron concentration per unit cell (VEC) in a half-Heusler (HH) material gives a large number of structures and substructures that can be exploited to improve the thermoelectric performance.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 72
Author(s):  
Dianta Ginting ◽  
Chan-Chieh Lin ◽  
Jong-Soo Rhyee

Thermoelectric power generation is an energy conversion technology from heat to electric energy, which can be applied to waste heat power conversion. Among thermoelectric materials (TE), PbTe-PbSe-PbS quaternary alloys and composites are promising candidates for thermoelectric power generation applications in the mid-temperature operating range from 500 to ~850 K. Besides, the thermoelectric performance of quaternary alloys and composites is not fully optimized regarding its composition and synthesis process. In the quaternary system, PbTe-PbSe-PbS, it was found that PbS will form nanoprecipitation in the matrix of quaternary alloy for a small content of PbS (≤0.07), which reduces the lattice thermal conductivity. The power factor of PbTe-PbSe-PbS quaternary alloys can be significantly enhanced by using a band convergence in PbTe1−xSex. The band structure modifications, with the result of simultaneous PbS nanoprecipitation, give rise to a high Z T value of 2.3 at 800 K for (PbTe)0.95−x(PbSe)x(PbS)0.05. The chemical potential tuning by effective K-doping ( x = 0.02) and PbS substitution reveals a high power factor and low thermal conductivity, resulting in a comparatively high Z T value of 1.72 at 800 K. The combination of a high Seebeck coefficient and low thermal conductivity results in a very high Z T value of 1.52 at 700 K as n-type materials for low Cl-doped ( x = 0.0005) (PbTe0.93−xSe0.07Clx)0.93(PbS)0.07 composites. Therefore, this review presents the simultaneous emergence of effective chemical potential tuning, band convergence, and nanoprecipitation, giving rise to a significant enhancement of the thermoelectric performance of both p - and n -type PbTe-PbSe-PbS quaternary alloy and composite TE materials.


RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1593-1599 ◽  
Author(s):  
Jonna Hynynen ◽  
David Kiefer ◽  
Christian Müller

The crystallinity of P3HT strongly benefits the electrical conductivity but not Seebeck coefficient, leading to an increase in power factor by one order of magnitude.


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