Simulation of reconstructions of the polar ZnO (0001) surfaces

TL;DR

This study uses Monte Carlo simulations with empirical potentials to explore surface reconstructions of polar ZnO(0001), revealing diverse triangular patterns that align with experimental observations.

Contribution

It introduces a simulation approach to predict surface patterns on ZnO(0001), emphasizing the role of dipole moment quenching in surface reconstruction energetics.

Findings

Multiple triangular surface patterns emerge during simulations.

Surface patterns are similar to experimentally observed structures.

No single size of islands or pits is energetically favored.

Abstract

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 favoured. 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.