Acoustic deformation potentials of n -type PbTe from first principles

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Murphy, Aoife R.
Murphy-Armando, Felipe
Fahy, Stephen B.
Savić, Ivana
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We calculate the uniaxial and dilatation acoustic deformation potentials Lu and Ld of the conduction band L valleys of PbTe from first principles, using the local density approximation (LDA) and hybrid functional (HSE03) exchange-correlation functionals. We find that the choice of a functional does not substantially affect the effective band masses and deformation potentials as long as a physically correct representation of the conduction band states near the band gap has been obtained. Fitting of the electron-phonon matrix elements obtained in density functional perturbation theory (DFPT) with the LDA excluding spin-orbit interaction (SOI) gives L u = 7.0 eV and L d = 0.4 eV. Computing the relative shifts of the L valleys induced by strain with the HSE03 functional including SOI gives L u = 5.5 eV and L d = 0.8 eV, in good agreement with the DFPT values. Our calculated values of L u agree fairly well with experiment (∼3–4.5 eV). The computed values of L d are substantially smaller than those obtained by fitting electronic transport measurements (∼17–22 eV), indicating that intravalley acoustic phonon scattering in PbTe is much weaker than previously thought.
Electrical conductivity , Electron-phonon coupling , Electronic structure , Density functional theory , Condensed matter and materials physics
Murphy, A. R., Murphy-Armando, F., Fahy, S. and Savić, I. (2018) 'Acoustic deformation potentials of $n$-type PbTe from first principles', Physical Review B, 98(8), 085201 (12pp). DOI: 10.1103/PhysRevB.98.085201