Simulation of reconstructions of the polar ZnO(0001) surfaces

Surface reconstructions on the polar ZnO(0001) surface are investigated using empirical potential models. Several possible reconstructions based around triangular motifs are investigated. The quenching of the dipole moment in the material dominates the energetics of the surface patterns so that no one particular size of surface triangular island or pit is strongly favored. We employ Monte Carlo simulations to explore which patterns emerge from a high-temperature quench and during deposition of additional ZnO monolayers. The simulations show that a range of triangular islands and pits evolve in competition with one another. The surface patterns we discover are qualitatively similar to those observed experimentally.