Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles

Abstract

Half-Heusler (HH) compounds, with a valence electron count of 8 or 18, have gained popularity as promising high-temperature thermoelectric (TE) materials due to their excellent electrical properties, robust mechanical capabilities, and good high-temperature thermal stability. With the help of first-principles calculations, great progress has been made in half-Heusler thermoelectric materials. In this review, we summarize some representative theoretical work on band structures and transport properties of HH compounds. We introduce how basic band-structure calculations are used to investigate the atomic disorder in n-type MNiSb (M = Ti, Zr, Hf) compounds and guide the band engineering to enhance TE performance in p-type FeRSb (R = V, Nb) based systems. The calculations on electrical transport properties, especially the scattering time, and lattice thermal conductivities are also demonstrated. The outlook for future research directions of first-principles calculations on HH TE materials is also discussed.

Decisive role of interstitial defects in half-Heusler semiconductors: An ab initio study

“…In the ongoing quest for materials that are capable of converting huge amount of available waste heat into valuable electrical energy [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], half-Heusler thermoelectric alloys [19][20][21][22][23][24][25][26][27][28][29] have lately attracted enormous attention. These alloys are ternary intermetallics with the three elements in 1:1:1 stoichiometric proportion as represented by the general formula XY Z (X and Y are transition metals and Z is nonmagnetic element) [30].…”

Thermal and Electronic Transport Properties of the Half-Heusler Phase ScNiSb

“…These materials show p -type behavior. For some of them (e.g., PtYSb), thermoelectric parameter values (e.g., ZT = 0.57 at 973 K [8]) are as good as for HH phases without RE [MNiSn, MCoSb (M = Ti, Zr, Hf) and XFeSb (X = V, Nb, Ta)] before optimization [13,14,15,16,17,18]. In recent years, the on-going intense studies on various RE-based HH phases have been focused on their other remarkable properties, like large magnetocaloric effect, huge magnetoresistance, superconductivity, presence of Dirac states, etc.…”

Approaching the minimum lattice thermal conductivity of p-type SnTe thermoelectric materials by Sb and Mg alloying

“…[1][2][3][4][5][6][7][8]. The conversion efficiency of TE devices is restricted by the Carnot efficiency and the dimensionless figure of merit zT, zT = a 2 rT/(j e + j L ), where a, r, j e , j L and T represent the Seebeck coefficient, the electrical conductivity, the electronic thermal conductivity, the lattice thermal conductivity, and the absolute temperature, respectively [9][10][11][12][13][14]. In order to enhance the conversion efficiency, a high Seebeck coefficient, a high electrical conductivity and a low thermal conductivity are required.…”