Strain-induced electronic band convergence: effect on the Seebeck coefficient of Mg2Si for thermoelectric applications

H. Balout (1) , P. Boulet , M. -C. Record (2)

1 Institut de Physique Nucléaire
2 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence

The present theoretical study, performed using density-functional theory and Boltzmann transport theory formalisms, shows that under 2.246 % isotropic tensile strain, the two energy-lowest conduction bands of Mg2Si overlap. The two, threefold-degenerated orbitals become a unique, sixfold-degenerated orbital. It is demonstrated that such degeneracy implies an increase of the Seebeck coefficient, of the electrical conductivity, of the power factor, and in fine of the figure of merit.

Mots clés: Silicides · Band structures · Density functional theory ·; Thermoelectricity · Isotropic constraints ·; Boltzmann transport theory

Domaines: Micro et nanotechnologies/Microélectronique

H. Balout, P. Boulet, M. -C. Record. Strain-induced electronic band convergence: effect on the Seebeck coefficient of Mg2Si for thermoelectric applications. Journal of Molecular Modeling, 2017, 23 (4), pp.130 - 130. ⟨10.1007/s00894-017-3304-1⟩. ⟨hal-01694202⟩