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
The thermoelectric performance of anisotropic SnSe doped with Na
TL;DR: In this paper, Na2Se as an acceptor was doped into lead-free polycrystalline SnSe in order to optimize the electrical transport properties, especially to increase the carrier concentration.
Journal ArticleDOI
Crystal Structure Induced Ultralow Lattice Thermal Conductivity in Thermoelectric Ag9AlSe6
Journal ArticleDOI
Temperature Trapping: Energy-Free Maintenance of Constant Temperatures as Ambient Temperature Gradients Change
TL;DR: A temperature-trapping theory for asymmetric phase-transition materials with thermally responsive thermal conductivities is established and a concept of an energy-free thermostat within ambient temperature gradients is theoretically introduced and experimentally demonstrated.
Journal ArticleDOI
Low-symmetry two-dimensional materials for electronic and photonic applications
TL;DR: In this article, the synthesis, properties, and novel device applications of low-symmetry 2D materials, including black phosphorus and its arsenic alloys, compounds with black-phosphorus-like structure such as the monochalcogenides of group IV elements like Ge and Sn, as well as the class of lowsymmetric transition metal dichal cogenide (TMDC) materials such as rhenium disulfide (ReS2) and ReSe2), are discussed.
Journal ArticleDOI
A facile chemical reduction approach for effectively tuning thermoelectric properties of PEDOT films
TL;DR: In this article, PEDOT-Tos-PPP films were prepared via a vapor phase polymerization (VPP) method and treated with NaBH 4 /DMSO solutions to adjust the redox level.
References
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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.