Structural, thermodynamic and electronic properties of zinc-blende AlN from first-principles calculations

Structural, thermodynamic and electronic properties of zinc-blende AlN under pressure are investigated by first-principles calculations based on the plane-wave basis set. Through the analysis of enthalpy variation of AlN in the zinc-blende (ZB) and the rock-salt (RS) structures with pressure, we find the phase transition of AlN from ZB to RS structure occurs at 6.7\,GPa. By using the quasi-harmonic Debye model, we obtain the heat capacity $C_{V}$, Debye temperature $\Th_{\rm D}$, Gr\"{u}neisen parameter $\gamma $ and thermal expansion coefficient $\alpha $. The electronic properties including fundamental energy gaps and hydrostatic deformation potentials are investigated and the dependence of energy gaps on pressure is analysed.