Assessing the quality of relaxation-time approximations with fully-automated computations of phonon-limited mobilities

Abstract

The mobility of carriers, as limited by their scattering with phonons, can now routinely be obtained from first-principles electron-phonon coupling calculations. However, so far, most computations have relied on some form of simplification of the linearized Boltzmann transport equation based on either the self-energy, the momentum- or constant relaxation time approximations. Here, we develop a high-throughput infrastructure and an automatic workflow and we compute 69 phonon-limited mobilities in semiconductors. We compare the results resorting to the approximations with the exact iterative solution. We conclude that the approximate values may deviate significantly from the exact ones and are thus not reliable. Given the minimal computational overhead, our work encourages to rely on this exact iterative solution and warns on the possible inaccuracy of earlier results reported using relaxation time approximations.

6 pages, 2 figures

References in corpus (4)

• BoltzTraP. A code for calculating band-structure dependent quantities
• Ab initio Electron Mobility and Polar Phonon Scattering in GaAs
• First-principles predictions of Hall and drift mobilities in semiconductors
• Convergence and pitfalls of density functional perturbation theory phonons calculations from a high-throughput perspective

Cited by in corpus (10)

• Long-range electrostatic contribution to the electron-phonon couplings and mobilities of two-dimensional and bulk materials
• Abinit 2025: New Capabilities for the Predictive Modeling of Solids and Nanomaterials
• Assessing carrier mobility, dopability, and defect tolerance in the chalcogenide perovskite BaZrS${}_3$
• Electron mobility of SnO2 from first principles
• Hierarchical Characterization of Thermoelectric Performance in Copper-Based Chalcogenide CsCu${}_3$S${}_2$: Unveiling the role of Anharmonic Lattice Dynamics
• Nonlinear Hall effect from long-lived valley-polarizing relaxons
• Band gap renormalization, carrier mobility, and transport in Mg${}_2$Si and Ca${}_2$Si: \textit{Ab initio} scattering and Boltzmann transport equation study
• Beyond-quasiparticle transport with vertex correction: self-consistent ladder formalism for electron-phonon interactions
• First-principles Prediction of Carrier Mobility in Semiconductor Nanowires Based on the Spatially Dependent Boltzmann Transport Equation
• Significant first-principles electron-phonon coupling effects in the LiZnAs and ScAgC half-Heusler thermoelectrics