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Enhanced thermoelectric performance is restricted greatly by the interaction of various transport parameters, and this bottleneck urgently requires a solution. In this paper, first-principles calculations and Boltzmann transport theory are used to study the thermoelectric performance of two-dimensional (PbX) 2 (X = S , Se , Te) monolayers, and it is found that the thermoelectric performance can be enhanced significantly by applying a biaxial tensile strain. The room-temperature ZT values of the p-type (PbS) 2 , (PbSe) 2 , and (PbTe) 2 in zigzag (armchair) directions are boosted as high as 1.97 (1.35), 2.26 (1.31), and 2.45 (1.59), respectively. The results show that it is mainly attributed to the significantly reduced phonon thermal conductivity. Moreover, the sharply reduced phonon thermal conductivity is mainly due to the enhancement of the phonon scattering rate caused by strong phonon anharmonicity. In addition, the excellent ZT value of the p-type (PbX) 2 (X = S , Se , Te) monolayer exhibits their potential application in the thermoelectric field, and the external strain has a good prospect in enhancing the thermoelectric performance. [ABSTRACT FROM AUTHOR]

Reliability problems caused by metal electromigration failure have attracted much attention, but it is barely investigated for thermoelectric semiconductors with increased current density in micro thermoelectric devices. Herein, we investigate electromigration reliability of a Bi2Te3 thermoelectric film with the current densities of ∼104 A/cm2. The failure mechanism and thermoelectric performance change of the Bi2Te3 film at different current densities by controlling the temperature are discussed, indicating the reliability issue is a comprehensive problem involving multiphysics effects. In addition, the activation energy of Bi2Te3 materials, as an essential electromigration parameter, is measured and calculated to be about 0.8 eV by the resistance change method. This work provides much guidance to the reliable service of thin-film TE devices operating under high current density. [ABSTRACT FROM AUTHOR]

We synthesized the solid solutions CuGa1-xInxTe2 (x = 0-1.0) by isoelectronic substitution of element In (Ga) for Ga(In) in the CuMTe2 (M = Ga, In) lattices and examined their thermoelectric properties. The structure upon substitution provides much high Seebeck coefficient (α), relatively low thermal (κ), and electrical conductivity (σ). AT 701 K, the α, σ, and κ are 283.15 µV K-1, 1.15 × 104 Ω-1 m-1, and 0.71 W m-1 K-1, respectively, for CuGa0.36In0.64Te2, which give the figure of merit (ZT) of 0.91, about two times those of the mother compounds CuGaTe2 and CuInTe2. This material holds great application perspectives at intermediate temperatures. [ABSTRACT FROM AUTHOR]