Hierarchical structures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST)

2021 ◽  
Author(s):  
Siqi Wang ◽  
Yu Xiao ◽  
Yongjin Chen ◽  
Shang Peng ◽  
Dongyang Wang ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Phonon Transport ◽  
Thermoelectric Performance

Hierarchical microstructures lead to high thermoelectric performance in Cum+nPb100SbmTe100Se2m (CLAST) through synergistically optimizing carrier and phonon transport.

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 .

scholarly journals High Thermoelectric Performance in SnTe Nanocomposites with All-Scale Hierarchical Structures

2020 ◽  
Vol 12 (20) ◽  
pp. 23102-23109 ◽  
Author(s):  
Qinghui Jiang ◽  
Huishan Hu ◽  
Junyou Yang ◽  
Jiwu Xin ◽  
Sihui Li ◽  
...  
Keyword(s):  
Hierarchical Structures ◽  
Thermoelectric Performance

Zr vacancy interfaces: an effective strategy for collaborative optimization of ZrNiSn-based thermoelectric performance

2019 ◽  
Vol 7 (45) ◽  
pp. 26053-26061 ◽  
Author(s):  
Yihua Zhang ◽  
Shuankui Li ◽  
Fusheng Liu ◽  
Chaohua Zhang ◽  
Lipeng Hu ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Thermoelectric Materials ◽  
Phonon Transport ◽  
Collaborative Optimization ◽  
Thermoelectric Performance ◽  
Effective Strategy

Grain boundaries play a key role in carrier/phonon transport in thermoelectric materials.

scholarly journals Phonon Transport and Thermoelectric Properties of Imidazole-Graphyne

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5604
Author(s):  
Yanyan Chen ◽  
Jie Sun ◽  
Wei Kang ◽  
Qian Wang
Keyword(s):  
Thermal Conductivity ◽  
Lattice Thermal Conductivity ◽  
Transport Theory ◽  
Hole Concentration ◽  
Chemical Properties ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Boltzmann Transport ◽  
Boltzmann Transport Theory ◽  
Carbon Based

The pentagon has been proven to be an important structural unit for carbon materials, leading to different physical and chemical properties from those of hexagon-based allotropes. Following the development from graphene to penta-graphene, a breakthrough has very recently been made for graphyne—for example, imidazole-graphyne (ID-GY) was formed by assembling experimentally synthesized pentagonal imidazole molecules and acetylenic linkers. In this work, we study the thermal properties and thermoelectric performance of ID-GY by combining first principle calculations with the Boltzmann transport theory. The calculated lattice thermal conductivity of ID-GY is 10.76 W/mK at 300 K, which is only one tenth of that of γ-graphyne (106.24 W/mK). A detailed analysis of the harmonic and anharmonic properties, including the phonon group velocity, phonon lifetime, atomic displacement parameter, and bond energy curves, reveals that the low lattice thermal conductivity can be attributed to the low Young’s modulus, low Debye temperature, and high Grüneisen parameter. Furthermore, at room temperature, ID-GY can reach a high ZT value of 0.46 with a 5.8 × 1012 cm−2 hole concentration, which is much higher than the value for many other carbon-based materials. This work demonstrates that changing structural units from hexagonal to pentagonal can significantly reduce the lattice thermal conductivity and enhance the thermoelectric performance of carbon-based materials.

Significantly enhanced thermoelectric performance in intermediate weak-coupling C8-BTBT molecular junction with p/n type electrode doping

2021 ◽  
Author(s):  
Bei Zhang ◽  
shidong zhang ◽  
Jiwei Dong ◽  
Yaoxing Sun ◽  
Fangping Ouyang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Transport Properties ◽  
Weak Coupling ◽  
Density Functional ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Molecular Junction ◽  
Functional Theory ◽  
Delicate Balance ◽  
Central Molecule

For single-molecular junction, inherent energy mismatch between central molecule and electrodes requires a delicate balance between electronic and phonon transport properties. Based on a combination of density functional theory and...

Ultralow lattice thermal conductivity and dramatically enhanced thermoelectric properties of monolayer InSe induced by external electric field

2021 ◽  
Author(s):  
Zheng Chang ◽  
Kunpeng Yuan ◽  
Zhehao Sun ◽  
Xiaoliang Zhang ◽  
Yufei Gao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
External Electric Field ◽  
Thermoelectric Properties ◽  
Electrostatic Interaction ◽  
Lattice Thermal Conductivity ◽  
Phonon Transport ◽  
Thermoelectric Performance

With the ability of altering the inherent interatomic electrostatic interaction, modulating external electric field strength is a promising approach to tune the phonon transport behavior and enhance thermoelectric performance of...

Tuning SnSe/SnS hetero-interfaces to enhance thermoelectric performance

2018 ◽  
Vol 11 (04) ◽  
pp. 1850069 ◽  
Author(s):  
Xuerui Liu ◽  
Shuankui Li ◽  
Tinyang Liu ◽  
Weiming Zhu ◽  
Rui Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Materials ◽  
High Performance ◽  
Multiple Scales ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Energy Filtering ◽  
Promising Strategy ◽  
Filtering Effect ◽  
Heterogeneous Nanostructure

With the development of nanotechnology, thermoelectric materials with complex heterogeneous nanostructure offer a promising approach to improve the thermoelectric performance. In this work, SnSe/SnS hetero-nanosheet was tuned by the epitaxial growth of SnSe on the few layers of SnS nanosheets. The heterojunction interface can optimize the carrier/phonon transport behavior by energy filtering effect and scattering the phonon in multiple scales. Compared with pristine SnSe, the power factor of SnSe/SnS hetero-nanosheet increases from 2.2[Formula: see text][Formula: see text]V/cmK2 to 3.21[Formula: see text][Formula: see text]V/cmK2 at 773[Formula: see text]K, whereas the thermal conductivity decreases significantly from 0.65[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] to 0.48[Formula: see text]W[Formula: see text][Formula: see text][Formula: see text]m[Formula: see text] at 773[Formula: see text]K. The maximum ZT of 0.5 is obtained at 773[Formula: see text]K in the SnSe/SnS hetero-nanosheets, which is 89% higher than pristine SnSe. This approach is proved to be a promising strategy to design high performance thermoelectric materials.

Intrinsically Ultralow Thermal Conductive Inorganic Solids for High Thermoelectric Performance

2021 ◽  
Author(s):  
Moinak Dutta ◽  
Debattam Sarkar ◽  
Kanishka Biswas
Keyword(s):  
Thermal Conductivity ◽  
Solid State ◽  
Thermoelectric Materials ◽  
Electrical Transport ◽  
Phonon Transport ◽  
Heat Energy ◽  
Thermoelectric Performance ◽  
Low Thermal Conductivity ◽  
Inorganic Solids

Thermoelectric materials which can convert heat energy to electricity relies on crystalline inorganic solid state compounds exhibiting low phonon transport (i.e. low thermal conductivity) without much inhibiting the electrical transport....

scholarly journals Enhanced Thermoelectric Performance of Polycrystalline Si0.8Ge0.2 Alloys through the Addition of Nanoscale Porosity

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2591
Author(s):  
S. Aria Hosseini ◽  
Giuseppe Romano ◽  
P. Alex Greaney
Keyword(s):  
Thermal Conductivity ◽  
Carrier Concentration ◽  
Phonon Scattering ◽  
Mean Free Path ◽  
Phonon Transport ◽  
Thermoelectric Performance ◽  
Boltzmann Transport ◽  
Nanoscale Structures ◽  
Electronic Thermal Conductivity ◽  
Significant Performance

Engineering materials to include nanoscale porosity or other nanoscale structures has become a well-established strategy for enhancing the thermoelectric performance of dielectrics. However, the approach is only considered beneficial for materials where the intrinsic phonon mean-free path is much longer than that of the charge carriers. As such, the approach would not be expected to provide significant performance gains in polycrystalline semiconducting alloys, such as SixGe1-x, where mass disorder and grains provide strong phonon scattering. In this manuscript, we demonstrate that the addition of nanoscale porosity to even ultrafine-grained Si0.8Ge0.2 may be worthwhile. The semiclassical Boltzmann transport equation was used to model electrical and phonon transport in polycrystalline Si0.8Ge0.2 containing prismatic pores perpendicular to the transport current. The models are free of tuning parameters and were validated against experimental data. The models reveal that a combination of pores and grain boundaries suppresses phonon conductivity to a magnitude comparable with the electronic thermal conductivity. In this regime, ZT can be further enhanced by reducing carrier concentration to the electrical and electronic thermal conductivity and simultaneously increasing thermopower. Although increases in ZT are modest, the optimal carrier concentration is significantly lowered, meaning semiconductors need not be so strongly supersaturated with dopants.

Relationships between hierarchical structure and properties in macromolecular systems

1987 ◽  
Vol 45 ◽  
pp. 440-443
Author(s):  
E. Baer
Keyword(s):  
Uniaxial Tension ◽  
Hierarchical Structure ◽  
Inorganic Material ◽  
Hierarchical Structures ◽  
Bone Collagen ◽  
Structure And Properties ◽  
Connective Tissues ◽  
Scale Level ◽  
Fibrous Protein ◽  
Macromolecular Systems

The most advanced macromolecular materials are found in plants and animals, and certainly the connective tissues in mammals are amongst the most advanced macromolecular composites known to mankind. The efficient use of collagen, a fibrous protein, in the design of both soft and hard connective tissues is worthy of comment. Very crudely, in bone collagen serves as a highly efficient binder for the inorganic hydroxyappatite which stiffens the structure. The interactions between the organic fiber of collagen and the inorganic material seem to occur at the nano (scale) level of organization. Epitatic crystallization of the inorganic phase on the fibers has been reported to give a highly anisotropic, stress responsive, structure. Soft connective tissues also have sophisticated oriented hierarchical structures. The collagen fibers are “glued” together by a highly hydrated gel-like proteoglycan matrix. One of the simplest structures of this type is tendon which functions primarily in uniaxial tension as a reinforced elastomeric cable between muscle and bone.

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