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arXiv · 1612.05344

New record of high ZT found in hybrid transition-metal-dichalcogenides

Yulou Ouyang·Yuee Xie·Zhongwei Zhang·Qing Peng·Yuanping Chen
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Abstract

The search for thermoelectrics with higher figures of merit (ZT) will never stop due to the demand of heat harvesting. Single layer transition metal dichalcogenides (TMD), namely MX2 (where M is a transition metal and X is a chalcogen) that have electronic band gaps are among the new materials that have been the focus of such research. Here, we investigate the thermoelectric transport properties of hybrid armchair-edged TMDs nanoribbons, by using the nonequilibrium Green's function technique combined with the first principles and molecular dynamics methods. We find a ZT as high as 7.4 in hybrid MoS2/MoSe2 nanoribbons at 800K, creating a new record for ZT. Moreover, the hybrid interfaces by substituting X atoms are more efficient than those by substituting M atoms to tune the ZT. The origin of such a high ZT of hybrid nanoribbons is the high density of the grain boundaries: the hybrid interfaces decrease thermal conductance drastically without a large penalty to electronic conductance.

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Yulou Ouyang, Yuee Xie, Zhongwei Zhang, Qing Peng, Yuanping Chen. 2016-12-16. New record of high ZT found in hybrid transition-metal-dichalcogenides. https://arxiv.org/abs/1612.05344

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