Effect of Piezoelectric Polarization on Phonon Relaxation Rates in Binary Wurtzite Nitrides

TL;DR

This paper investigates how piezoelectric polarization affects phonon relaxation rates in binary wurtzite nitrides, impacting their thermal conductivity by considering various scattering processes.

Contribution

It provides a detailed calculation of modified phonon relaxation rates in GaN, AlN, and InN considering multiple scattering mechanisms influenced by PZ polarization.

Findings

Piezoelectric polarization increases phonon group velocity.

Modified phonon relaxation rates are quantitatively characterized.

Implications for thermal conductivity in nitrides are discussed.

Abstract

The piezoelectric (PZ) polarization effect enhances the phonon group velocity in wurtzite nitrides. This enhancement influences the phonon relaxation rates. We calculate the modified phonon relaxation rates in binary wurtzite nitrides (GaN, AlN and InN) by considering process like umklapp process, point defect, dislocation, boundary and phonon-electron scattering. The result will be useful to study the effect of PZ polarization on thermal conductivity of binary wurtzite nitrides (GaN, AlN and InN).