Two-phonon scattering in non-polar semiconductors: a first-principles study of warm electron transport in Si

Abstract

The ab-initio theory of charge transport in semiconductors typically employs the lowest-order perturbation theory in which electrons interact with one phonon (1ph). This theory is accepted to be adequate to explain the low-field mobility of non-polar semiconductors but has not been tested extensively beyond the low-field regime. Here, we report first-principles calculations of the electric field-dependence of the electron mobility of Si as described by the warm electron coefficient, $\beta$. Although the 1ph theory overestimates the low-field mobility by only around 20%, it overestimates $\beta$ by over a factor of two over a range of temperatures and crystallographic axes. We show that the discrepancy in $\beta$ is reconciled by inclusion of on-shell iterated 2-phonon (2ph) scattering processes, indicating that scattering from higher-order electron-phonon interactions is non-negligible even in non-polar semiconductors. Further, a ~20% underestimate of the low-field mobility with 2ph scattering suggests that non-trivial cancellations may occur in the perturbative expansion of the electron-phonon interaction.

18 pages, 3 figures, submitted

References in corpus (10)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Phonon-assisted optical absorption in silicon from first principles
• Ab initio Electron Mobility and Polar Phonon Scattering in GaAs
• First-principles dynamics of electrons and phonons
• Long-range quadrupole electron-phonon interaction from first principles
• Magnetotransport in semiconductors and two-dimensional materials from first principles
• Ab initio electron dynamics in high electric fields: accurate predictions of velocity-field curves
• High-field transport and hot electron noise in GaAs from first principles: role of two-phonon scattering
• Electronic noise of warm electrons in semiconductors from first-principles
• High-field charge transport and noise in p-Si from first principles

Cited by in corpus (2)

• Transport and noise of hot electrons in GaAs using a semi-analytical model of two-phonon polar optical phonon scattering
• Beyond-quasiparticle transport with vertex correction: self-consistent ladder formalism for electron-phonon interactions