Acoustic deformation potentials of n -type PbTe from first principles
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Published version
Date
2018-08-03
Authors
Murphy, Aoife R.
Murphy-Armando, Felipe
Fahy, Stephen B.
Savić, Ivana
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Published Version
Abstract
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.
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Keywords
Electrical conductivity , Electron-phonon coupling , Electronic structure , Density functional theory , Condensed matter and materials physics
Citation
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