Structural, Electronic and Mechanical Properties of Few-Layer GaN Nanosheet: A First-Principle Study

Abstract

The low-dimensional III-V semiconductors are interesting candidate materials for the tailoring of two dimensional (2D) layered structures. We have performed the first-principles calculations on the structural, electronic, and mechanical properties of few-layer gallium nitride (GaN) nanosheet, formed from various bulk phases and stacking patterns, to investigate the effects of structural modification and sheet thickness on their structural, electronic, and mechanical properties. We observed that with the thickness increases, few-layer GaN nanosheets have suffered from the size-induced transition from indirect semiconductor to metallic as well as from the graphitic – planar honeycomb to the wurtzite buckled 2D form. Optimized geometries, binding energy, phonon spectra, electronic band structure, and elastic tensor calculation has ensured the dynamical and mechanical stability of the sheet. Our study indicates that there are two competing mechanisms that govern the polarity compensation with the sheet’s net dipole served as an important parameter for determining the sheet’s stable formation.