Huge power factor in p-type half-Heusler alloys NbFeSb and TaFeSb

TY - JOUR

T1 - Huge power factor in p-type half-Heusler alloys NbFeSb and TaFeSb

AU - Naydenov, Genadi Antonov

AU - Hasnip, Philip James

AU - Probert, Matthew Ian James

AU - Lazarov, Vlado

N1 - © 2019 The Author(s)

PY - 2019/6/3

Y1 - 2019/6/3

N2 - NbFeSb is a promising thermoelectric material which according to experimental and theoretical studies exhibits a high power factor of up to 10 mW/(m.K^2) at room temperature and ZT of 1 at 1000 K. In all previous theoretical studies, κ_latt is calculated using simplified models, which ignore structural defects. In this work, we calculate κ_latt by solving the Boltzmann Transport Equation and subsequently including the contributions of grain boundaries, point defects and electron-phonon interaction. The results for κ_latt and ZT are in excellent agreement with experimental measurements. In addition, we investigate theoretically the thermoelectric properties of TaFeSb. The material has recently been synthesised experimentally, thus conrming the theoretical hypothesis for its stability. This encourages a full-scale computation of its thermoelectric performance.Our results show that TaFeSb is indeed an excellent thermoelectric material which has an unprecedentedly high power factor of 16 mW/(m.K^2) at room temperature and ZT of 1.5 at 1000 K.

AB - NbFeSb is a promising thermoelectric material which according to experimental and theoretical studies exhibits a high power factor of up to 10 mW/(m.K^2) at room temperature and ZT of 1 at 1000 K. In all previous theoretical studies, κ_latt is calculated using simplified models, which ignore structural defects. In this work, we calculate κ_latt by solving the Boltzmann Transport Equation and subsequently including the contributions of grain boundaries, point defects and electron-phonon interaction. The results for κ_latt and ZT are in excellent agreement with experimental measurements. In addition, we investigate theoretically the thermoelectric properties of TaFeSb. The material has recently been synthesised experimentally, thus conrming the theoretical hypothesis for its stability. This encourages a full-scale computation of its thermoelectric performance.Our results show that TaFeSb is indeed an excellent thermoelectric material which has an unprecedentedly high power factor of 16 mW/(m.K^2) at room temperature and ZT of 1.5 at 1000 K.

KW - thermoelectric

KW - DENSITY FUNCTIONAL THEORY

KW - CASTEP

U2 - 10.1088/2515-7639/ab16fb

DO - 10.1088/2515-7639/ab16fb

M3 - Article

VL - 2

JO - Journal of physics : Materials

JF - Journal of physics : Materials

IS - 3

M1 - 035002

ER -