scholarly journals Formation of Dense Pore Structure by Te Addition in Bi0.5Sb1.5Te3: An Approach to Minimize Lattice Thermal Conductivity

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Syed Waqar Hasan ◽  
Hyeona Mun ◽  
Sang Il Kim ◽  
Jung Young Cho ◽  
Jong Wook Roh ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Power Factor ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Synergetic Effects ◽  
Spark Plasma ◽  
P Type

We herein report the electronic and thermal transport properties of p-type Bi0.5Sb1.5Te3polycrystalline bulks with dense pore structure. Dense pore structure was fabricated by vaporization of residual Te during the pressureless annealing of spark plasma sintered bulks of Te coated Bi0.5Sb1.5Te3powders. The lattice thermal conductivity was effectively reduced to the value of 0.35 W m−1 K−1at 300 K mainly due to the phonon scattering by pores, while the power factor was not significantly affected. An enhancedZTof 1.24 at 300 K was obtained in spark plasma sintered and annealed bulks of 3 wt.% Te coated Bi0.5Sb1.5Te3by these synergetic effects.

scholarly journals Reduction of Lattice Thermal Conductivity in PbTe Induced by Artificially Generated Pores

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Yeol Hwang ◽  
Eun Sung Kim ◽  
Syed Waqar Hasan ◽  
Soon-Mok Choi ◽  
Kyu Hyoung Lee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Transport Properties ◽  
Thermoelectric Materials ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Phonon Modes ◽  
Thermal Transport Properties

Highly dense pore structure was generated by simple sequential routes using NaCl and PVA as porogens in conventional PbTe thermoelectric materials, and the effect of pores on thermal transport properties was investigated. Compared with the pristine PbTe, the lattice thermal conductivity values of pore-generated PbTe polycrystalline bulks were significantly reduced due to the enhanced phonon scattering by mismatched phonon modes in the presence of pores (200 nm–2 μm) in the PbTe matrix. We obtained extremely low lattice thermal conductivity (~0.56 W m−1 K−1at 773 K) in pore-embedded PbTe bulk after sonication for the elimination of NaCl residue.

scholarly journals Excellent Room-Temperature Thermoelectricity of 2D GeP3: Mexican-Hat-Shaped Band Dispersion and Ultralow Lattice Thermal Conductivity

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6376
Author(s):  
Cong Wang ◽  
Zhiyuan Xu ◽  
Ke Xu ◽  
Guoying Gao
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Transport Theory ◽  
Phonon Scattering ◽  
Quantum Confinement Effect ◽  
Boltzmann Transport Theory ◽  
Mexican Hat ◽  
P Type

Although some atomically thin 2D semiconductors have been found to possess good thermoelectric performance due to the quantum confinement effect, most of their behaviors occur at a higher temperature. Searching for promising thermoelectric materials at room temperature is meaningful and challenging. Inspired by the finding of moderate band gap and high carrier mobility in monolayer GeP3, we investigated the thermoelectric properties by using semi-classical Boltzmann transport theory and first-principles calculations. The results show that the room-temperature lattice thermal conductivity of monolayer GeP3 is only 0.43 Wm−1K−1 because of the low group velocity and the strong anharmonic phonon scattering resulting from the disordered phonon vibrations with out-of-plane and in-plane directions. Simultaneously, the Mexican-hat-shaped dispersion and the orbital degeneracy of the valence bands result in a large p-type power factor. Combining this superior power factor with the ultralow lattice thermal conductivity, a high p-type thermoelectric figure of merit of 3.33 is achieved with a moderate carrier concentration at 300 K. The present work highlights the potential applications of 2D GeP3 as an excellent room-temperature thermoelectric material.

scholarly journals Study of anisotropic thermal conductivity in textured thermoelectric alloys by Raman spectroscopy

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24456-24465
Author(s):  
Rapaka S. C. Bose ◽  
K. Ramesh
Keyword(s):  
Crystal Structure ◽  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Transport Properties ◽  
Thermal Transport ◽  
Layered Crystal ◽  
Layered Crystal Structure ◽  
Thermal Transport Properties ◽  
Anisotropic Thermal Conductivity ◽  
P Type

Polycrystalline p-type Sb1.5Bi0.5Te3 (SBT) and n-type Bi2Te2.7Se0.3 (BTS) compounds possessing layered crystal structure show anisotropic electronic and thermal transport properties.

A High Thermoelectric Performance ZT in p-Type LaSe2 Crystal

2021 ◽  
Vol 871 ◽  
pp. 203-207
Author(s):  
Jian Liu
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
High Power ◽  
Density Functional ◽  
Lattice Thermal Conductivity ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Boltzmann Transport ◽  
High Power Factor ◽  
P Type

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 .

The Influence of RuO2 Addition on the Thermoelectric Properties of BiSbTe Alloys

2012 ◽  
Vol 512-515 ◽  
pp. 1651-1654 ◽  
Author(s):  
Yu Kun Xiao ◽  
Zhi Xiang Li ◽  
Jun Jiang ◽  
Sheng Hui Yang ◽  
Ting Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Combined Process ◽  
Plasma Sintering ◽  
The Matrix ◽  
Spark Plasma ◽  
Xrd Patterns ◽  
Factor Α ◽  
P Type

P-type BiSbTe/RuO2 composite was fabricated using a combined process of melting and spark plasma sintering. The XRD patterns showed that RuO2 reacted with the matrix for the RuO2 content of 1.0 wt% and 4.0 wt% samples. The measured thermoelectric properties showed that the highest electrical conductivity was obtained for the sample with 2.0 wt% RuO2. The power factor (α2σ/κ) decreased with the increase of RuO2 below 450 K. The lattice thermal conductivity was lower than that of BiSbTe over the whole temperature range for BiSbTe/2.0 wt% RuO2.

Thermal transport properties of monolayer MoSe2 with defects

2020 ◽  
Vol 22 (10) ◽  
pp. 5832-5838 ◽  
Author(s):  
Jiang-Jiang Ma ◽  
Jing-Jing Zheng ◽  
Wei-Dong Li ◽  
Dong-Hong Wang ◽  
Bao-Tian Wang
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Thermal Transport ◽  
Lattice Thermal Conductivity ◽  
Thermal Transport Properties

The defects in monolayer MoSe2 have a significant effect on its lattice thermal conductivity.

scholarly journals Is LiI a Potential Dopant Candidate to Enhance the Thermoelectric Performance in Sb-Free GeTe Systems? A Prelusive Study

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 643 ◽  
Author(s):  
Bhuvanesh Srinivasan ◽  
David Berthebaud ◽  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Short Communication ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Plasma Sintering ◽  
Spark Plasma

As a workable substitute for toxic PbTe-based thermoelectrics, GeTe-based materials are emanating as reliable alternatives. To assess the suitability of LiI as a dopant in thermoelectric GeTe, a prelusive study of thermoelectric properties of GeTe1−xLiIx (x = 0–0.02) alloys processed by Spark Plasma Sintering (SPS) are presented in this short communication. A maximum thermoelectric figure of merit, zT ~ 1.2, was attained at 773 K for 2 mol% LiI-doped GeTe composition, thanks to the combined benefits of a noted reduction in the thermal conductivity and a marginally improved power factor. The scattering of heat carrying phonons due to the presumable formation of Li-induced “pseudo-vacancies” and nano-precipitates contributed to the conspicuous suppression of lattice thermal conductivity, and consequently boosted the zT of the Sb-free (GeTe)0.98(LiI)0.02 sample when compared to that of pristine GeTe and Sb-rich (GeTe)x(LiSbTe2)2 compounds that were reported earlier.

THERMOELECTRIC PROPERTIES OF p-TYPE SKUTTERUDITES (Pr0.25Nd0.75)xFe3CoSb12 BY LEVITATION MELTING AND SPARK PLASMA SINTERING

2013 ◽  
Vol 06 (05) ◽  
pp. 1340006 ◽  
Author(s):  
JINGSHU XU ◽  
CHENGUANG FU ◽  
JIAN XIE ◽  
XINBING ZHAO ◽  
TIEJUN ZHU
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Lattice Thermal Conductivity ◽  
Levitation Melting ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

The p-type skutterudite compounds of ( Pr 0.25 Nd 0.75)x Fe 3 CoSb 12 (x = 0.67–0.78) have been successfully synthesized by levitation melting followed by annealing and spark plasma sintering. The thermoelectric properties have been characterized by the measurements of Seebeck coefficient, electrical conductivity and thermal conductivity in the temperature range from 300 K to 850 K. The improvement in the thermoelectric properties was realized due to the reduction in the lattice thermal conductivity when the voids were partially filled by Pr 0.25 Nd 0.75. The maximum ZT value of ~ 0.83 for ( Pr 0.25 Nd 0.75)0.76 Fe 3 CoSb 12 was obtained at 700 K.

scholarly journals Influence of Te Vacancies on the Thermoelectric Properties of n-type Cu0.008Bi2Te2.7-xSe0.3

2020 ◽  
Vol 58 (10) ◽  
pp. 721-727
Author(s):  
Yerim Yang ◽  
TaeWan Kim ◽  
Seokown Hong ◽  
Jiwoo An ◽  
Sang-il Kim
Keyword(s):  
Thermal Conductivity ◽  
Transport Properties ◽  
Point Defect ◽  
Thermoelectric Properties ◽  
Thermal Transport ◽  
Phonon Scattering ◽  
Band Model ◽  
Total Thermal Conductivity ◽  
Thermal Transport Properties ◽  
Callaway Model

In this study, we report the influence of Te vacancy formation on the thermoelectric properties of n-type Cu0.008Bi2Te2.7Se0.3 alloys, including their electronic and thermal transport properties. Te-deficient Cu0.008Bi2Te2.7-xSe0.3 (x = 0, 0.005, 0.01 and 0.02) samples were systematically synthesized and characterized. Regarding electronic transport properties, carrier concentration was increased with Te vacancies, while carrier mobility was maintained. As a result, the electrical conductivity significantly increased while the Seebeck coefficient reduced moderately, thus, the power factor was enhanced from 3.04 mW/mK<sup>2</sup> (pristine) to 3.22 mW/mK<sup>2</sup> (x = 0.02) at 300 K. Further analysis based on a single parabolic band model revealed that the weighted mobility of the conduction band increased, which is favorable for electron transport, as Te vacancies were generated. Regarding thermal transport properties, lattice thermal conductivity decreased with Te vacancies due to additional point defect phonon scattering, however, total thermal conductivity increased due to larger electronic contribution as Te vacancies increased. Analysis using the Debye-Callaway model suggests that the phonon scattering by the Te vacancies is as efficient as the substitution point defect scattering. Consequently, the thermoelectric figure of merit zT increased at all temperatures for x = 0.005 and 0.01. The maximum zT of 0.95 was achieved for Te-deficient Cu0.008Bi2Te2.69Se0.3 (x = 0.01) at 400 K.

Strain Engineering of Polar Optical Phonon Scattering Mechanism – An Effective Way to Optimize the Power-factor and Lattice Thermal Conductivity of ScN

2021 ◽  
Author(s):  
Iyyappa Rajan Panneerselvam ◽  
Man Hea Kim ◽  
Carlos Baldo III ◽  
Yan Wang ◽  
Mahalakshmi Sahasranaman
Keyword(s):  
Thermal Conductivity ◽  
Power Factor ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Material Selection ◽  
Strain Engineering ◽  
Polar Optical Phonon ◽  
Thermoelectric Power Factor ◽  
Optical Phonon Scattering

The tug-of-war between the thermoelectric power factor and the figure-of-merit complicates thermoelectric material selection, particularly for mid-to-high temperature thermoelectric materials. Approaches to reduce lattice thermal conductivity while maintaining a high-power...

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