Phonon Properties of Armchair and Zigzag Edged GaN Nanoribbon

Abstract

Of late, two dimensional (2D) gallium nitride (GaN) has appealed a great attention in nanoelectronic and optoelectronic applications due to its outstanding optical, electrical, and thermal properties. In this paper, we have explored the phonon properties of armchair and zigzag edged GaN nanoribbons using molecular dynamics simulation. The effect of edges and vacancies on the phonon thermal conductance, band structure, transmission spectrum and phonon density of states is explored systematically. Due to the reduced phonon-boundary scattering effect, the zigzag edged nanoribbon shows improved phonon behaviors than the armchair edge nanoribbon. With the increase of vacancy concentration, we have found a softening behavior of the low frequency phonon peaks in the phonon density of states. In addition, disappearing of phonon branches from the lower and higher energy range and inclusion of new phonon branches in the middle energy range of the phonon band structures are also noticed in the vacancy defected nanoribbons. These findings might be beneficial to design GaN based nanoelectronic and optoelectronic devices with improved thermal performances.