First-principles investigation on the thermoelectric performance of half-Heusler compound CuLiX(X = Se, Te)

Abstract

The remarkable thermoelectric performance is predicted for half-Heusler (HH) compounds of CuLiX (X = Se, Te) based on the first-principles calculation, the deformation potential (DP) theory, and semi-classical Boltzmann theory. The Slack model is employed to evaluate the lattice thermal conductivity and the result is in good agreement with the previously reported data. The results of mechanical properties demonstrate that CuLiSe is ductile but CuLiTe is brittle. The relaxation time and the carrier mobility are calculated with DP theory. The electrical and thermal conductivities are obtained by using the semi-classical Boltzmann theory based on the relaxation approximation. The Seebeck coefficient and power factor are obtained and their characters are analyzed. The dimensionless figure of merits (ZT) is obtained for the p- and n-type CuLiX. The maximum ZT of 2.65 can be achieved for n-type CuLiTe at the carrier concentration of 3.19 × 1019 cm−3 and 900 K, which indicates that this compound is a very promising candidate for the highly efficient thermoelectric materials.

Exploring structural, mechanical, and thermoelectric properties of half-Heusler compounds RhBiX (X = Ti, Zr, Hf): A first-principles investigation

“… 28 CuLiX (X = Se, Te) is considered an excellent thermoelectric material because of its high thermoelectric superiority value, where the value of CuLiTe (CuLiSe) is equal to 2.65 (1.7). 29 For KBiX (X = Ba, Sr), based on theoretical calculation, ZT reached 2.68 (1.56) for KBiBa (KBiSr). 30 J. Carrete used an ab initio method to screen a batch of structurally stable HH compounds and predicted that the materials had small lattice thermal conductivity.…”

Significantly (00l)-textured Ag2Se thin films with excellent thermoelectric performance for flexible power applications

“…8 In comparison, inorganic thin films deposited at flexible substrates have more potential to achieve high thermoelectric performance, as the reported high ZT s in relevant bulk materials. Until now, inorganic bulks including Bi 2 Te 3 , 9 SnSe, 10 Cu 2 Se, 11 filled CoSb 3 , 12 GeTe, 13 MgSb, 14 and Half-Heuslers 15 all have reported ZT values exceeding 1.5, and the corresponding thin films usually have ZT values over 0.5. For instance, a high estimated ZT value ∼1.2 at 600 K is achieved from SnSe based thin films along the in-plane direction, 16 a high ZT of ∼1.5 at 300 K in p-type Bi 0.5 Sb 1.5 Te 3 thin films is reported, 17 and n-type Ag/In co-doped CoSb 3 thin films presented a high ZT of ∼0.65 at 623 K. 18 However, the ZT value of flexible thin films is usually lower than that of its bulk due to the smaller grains, numerous grain boundaries and point defects which may seriously hinder the electrical transport and reduce the ZT values.…”

Electronic Structure-, Phonon Spectrum-, and Effective Mass- Related Thermoelectric Properties of PdXSn (X = Zr, Hf) Half Heuslers

“…XCoSb (X = Ti, Zr, Hf) compounds have gained attention because of their ZT value, which is equal to 1.0 at 1097 K with p-type doping [ 20 , 21 ]. K. Jia et al found that CuLiX(X = Se, Te) are a good thermoelectric material due to their high ZT value, which is equal to 2.65 (1.7) for CuLiTe (CuLiSe) [ 22 ]. FeNbSb-based half Heusler compounds have also been explored, and their value of ZT is >1 [ 23 , 24 ].…”