Piezoelectric Polarization Effect And Phonon Relaxation Rates In Binary Wurtzite Nitrides

Sushant K. Sahoo1*, Bijay K. Sahoo2, Sukadev Sahoo3

1Department of Physics, K.I.I.T. University, Bhubaneswar 751024, India

2Department of Physics, N.I.T, Raipur 492010, India

3Department of Physics, N.I.T, Durgapur 713209, India

Adv. Mater. Lett., 2014, 5 (2), pp 80-83

DOI: 10.5185/amlett.2013.fdm.26

Publication Date (Web): Jan 27, 2014

E-mail: physushant@gmail.com

Abstract


The piezoelectric (PZ) polarization property present in the wurtzite nitrides modifies the group velocity of phonons. As a result, the relaxation rates of phonons are changed. In this paper, we have calculated the relaxation rate of phonons as functions of the phonon frequency in binary wurtzite nitrides (GaN, AlN and InN) using the modified phonon group velocity. Different scattering mechanisms such as Umklapp, point defect, dislocation, boundary and phonon-electron scattering processes have been considered. The percentage change in phonon relaxation rates is found to be maximum for InN and minimum for GaN. This result can be used to study the effect of PZ polarization property on thermal conductivity of these materials.

Keywords

Binary wurtzite nitrides, piezoelectric polarization, group velocity of phonons, phonon relaxation rates

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