Impact of polytypism on the ground state properties of zinc oxide: A firstprinciples study

The last past two decades have witnessed tremendous scientific and technological interest in zinc-oxide (ZnO), a wide-band gap II-VI semiconductor with unparalleled optoelectronic, piezoelectric, thermal and transport properties. Herein, we present a clear view of the electronic structure properties of cubic (3C), hexagonal (2H, 4H, and 6H) and body-centered tetragonal polytypes of ZnO using stat-of-the-art first-principles pseudopotentials method. All the crystal structures studied evince marked energetic stabilities, rivaling with the ground-state wurtzite 2H phase. Furthermore, the calculations of the elastic constants and phonon dispersion evidence the mechanical and dynamical stabilities of the four ZnO-polymorphs. In addition, the impact of the stacking order on the structural, energetic, electronic, piezoelectric, and dynamical properties is explored and examined.