Impact of phonons and spin-orbit coupling on Auger recombination in InAs

Abstract

We extend the methodology for calculating Auger recombination from first principles to include spin-orbit interaction, which allows us to study materials in which the spin-orbit splitting and the band gap are of similar magnitude. We use this methodology to compute the direct and indirect Auger coefficients in InAs and related alloys. The direct process involves only Coulomb interaction, while the indirect process is mediated by phonons. We show how the spin-orbit split-off states allow for efficient direct Auger recombination, greatly enhancing the excitation rate of Auger holes due to a near resonance between the spin-orbit splitting and the band gap of the material. We find that the direct hole-hole-electron Auger recombination coefficient decays exponentially with increasing band gap, while the electron-electron-hole Auger recombination coefficient decays faster than exponentially. Additionally, we modeled the phonon-assisted process in InAs and show that the direct Auger process is dominant.

Phonon-assisted Auger-Meitner Recombination in Silicon from First Principles

“…Previous work on AMR in InAs found that including spin-orbit coupling did not appreciably alter the AMR rate unless the splitting was large enough to form resonant states with the band gap. [22] Given that the spin-orbit splitting in silicon is significantly smaller than the band gap, we can safely omit it from our calculations in order to reduce the computational cost without suffering any severe loss of accuracy.…”