Journal ArticleDOI
Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals
Li-Dong Zhao,Shih Han Lo,Yongsheng Zhang,Hui Sun,Gangjian Tan,Ctirad Uher,Chris Wolverton,Vinayak P. Dravid,Mercouri G. Kanatzidis +8 more
TLDR
An unprecedented ZT of 2.6 ± 0.3 at 923 K is reported in SnSe single crystals measured along the b axis of the room-temperature orthorhombic unit cell, which highlights alternative strategies to nanostructuring for achieving high thermoelectric performance.Abstract:
The thermoelectric effect enables direct and reversible conversion between thermal and electrical energy, and provides a viable route for power generation from waste heat The efficiency of thermoelectric materials is dictated by the dimensionless figure of merit, ZT (where Z is the figure of merit and T is absolute temperature), which governs the Carnot efficiency for heat conversion Enhancements above the generally high threshold value of 25 have important implications for commercial deployment, especially for compounds free of Pb and Te Here we report an unprecedented ZT of 26 ± 03 at 923 K, realized in SnSe single crystals measured along the b axis of the room-temperature orthorhombic unit cell This material also shows a high ZT of 23 ± 03 along the c axis but a significantly reduced ZT of 08 ± 02 along the a axis We attribute the remarkably high ZT along the b axis to the intrinsically ultralow lattice thermal conductivity in SnSe The layered structure of SnSe derives from a distorted rock-salt structure, and features anomalously high Gruneisen parameters, which reflect the anharmonic and anisotropic bonding We attribute the exceptionally low lattice thermal conductivity (023 ± 003 W m(-1) K(-1) at 973 K) in SnSe to the anharmonicity These findings highlight alternative strategies to nanostructuring for achieving high thermoelectric performanceread more
Citations
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Journal ArticleDOI
Selectively tuning ionic thermopower in all-solid-state flexible polymer composites for thermal sensing
Cheng Chi,Meng An,Xin Qi,Yan Li,Ruihan Zhang,Gongze Liu,Chongjia Lin,He Huang,Hao Dang,Baris Demir,Yan Wang,Weigang Ma,Baoling Huang,Ming Zhang +13 more
TL;DR: In this paper , the mechanism of p-n conversion in all-solid-state ionic thermoelectric polymer material at the atomic scale was presented based on the analysis of Eastman entropy changes by molecular dynamics simulation.
Journal ArticleDOI
Strain effect on electronic structure and thermoelectric properties of orthorhombic SnSe: A first principles study
TL;DR: In this article, the Seebeck coefficients were obtained by solving Boltzmann Transport equation (BTE) with interpolated band energies, and the strain effect on thermoelectricity of orthorhombic SnSe was studied using density function theory.
Journal ArticleDOI
N-Type Bismuth Telluride Nanocomposite Materials Optimization for Thermoelectric Generators in Wearable Applications
TL;DR: High-performance nanocomposites of n-type Bi2Te2.7Se0.3, optimized especially for body heat harvesting and power generation applications, are synthesized and compared with each other to optimize the temperature-dependent thermoelectric properties.
Journal ArticleDOI
Rock-salt-type nanoprecipitates lead to high thermoelectric performance in undoped polycrystalline SnSe
TL;DR: In this paper, the authors reported a high ZT value of 1.3 at 850 K for undoped polycrystalline SnSe, which is attributed to a synergistic combination of enhanced power factor and reduction of the lattice thermal conductivity.
Journal ArticleDOI
Advances in thermoelectrics: From single phases to hierarchical nanostructures and back
TL;DR: In this paper, the authors describe their long-standing efforts to advance ZT to record levels starting from exploratory synthesis and evolving into the nanostructuring and panoscopic paradigm, which has helped to usher in a new era of investigation for thermoelectrics.
References
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Journal ArticleDOI
Generalized Gradient Approximation Made Simple
TL;DR: A simple derivation of a simple GGA is presented, in which all parameters (other than those in LSD) are fundamental constants, and only general features of the detailed construction underlying the Perdew-Wang 1991 (PW91) GGA are invoked.
Journal ArticleDOI
From ultrasoft pseudopotentials to the projector augmented-wave method
Georg Kresse,Daniel P. Joubert +1 more
TL;DR: In this paper, the formal relationship between US Vanderbilt-type pseudopotentials and Blochl's projector augmented wave (PAW) method is derived and the Hamilton operator, the forces, and the stress tensor are derived for this modified PAW functional.
Journal ArticleDOI
Special points for brillouin-zone integrations
Hendrik J. Monkhorst,J.D. Pack +1 more
TL;DR: In this article, a method for generating sets of special points in the Brillouin zone which provides an efficient means of integrating periodic functions of the wave vector is given, where the integration can be over the entire zone or over specified portions thereof.
Journal ArticleDOI
Complex thermoelectric materials.
TL;DR: A new era of complex thermoelectric materials is approaching because of modern synthesis and characterization techniques, particularly for nanoscale materials, and the strategies used to improve the thermopower and reduce the thermal conductivity are reviewed.
Journal ArticleDOI
High-performance bulk thermoelectrics with all-scale hierarchical architectures
Kanishka Biswas,Jiaqing He,Ivan Blum,Ivan Blum,Chun I. Wu,Timothy P. Hogan,Timothy P. Hogan,David N. Seidman,Vinayak P. Dravid,Mercouri G. Kanatzidis,Mercouri G. Kanatzidis +10 more
TL;DR: It is shown that heat-carrying phonons with long mean free paths can be scattered by controlling and fine-tuning the mesoscale architecture of nanostructured thermoelectric materials, and an increase in ZT beyond the threshold of 2 highlights the role of, and need for, multiscale hierarchical architecture in controlling phonon scattering in bulk thermoeLECTrics.