Polarons in Wurtzite Nitride Semiconductors

TL;DR

This paper calculates polaron properties in wurtzite nitride semiconductors, incorporating anisotropic electron-phonon interactions and second-order corrections, with specific results for GaN.

Contribution

It introduces a Frohlich-like Hamiltonian accounting for LO and TO polarization mixing in anisotropic wurtzite structures and computes polaron characteristics including damping rates.

Findings

Electron-phonon coupling in GaN is strong, requiring second-order corrections.

Polaron binding energy and effective mass are quantitatively evaluated.

Finite temperature damping rates are determined.

Abstract

Polaron binding energy and effective mass are calculated for semiconductors with wurtzite crystalline structure from the first order electron-phonon corrections to the self-energy. A recently introduced Frohlich-like electron-phonon interaction Hamiltonian which accounts for the LO and TO polarizations mixing due to the anisotropy is used in the calculation. The polaronic damping rates are evaluated for finite temperature. Numerical results are reported for GaN. It is shown that the electron-phonon coupling is strong enough to justify the necessity of the inclusion of second-order corrections.