Defects in oxide ultrathin films and 2D materials

Defects, that are irregularities in crystal lattices, create special sites or regions of particular geometry, electronic structure and activity that influence the physical and chemical behavior of the materials in a significant way. Here we examine published work on defects in two-dimensional (2D) oxide systems. The latter have attracted interest and significance in many areas of modern science and technology in recent years. The defects are classified according to their dimensionality: point defects, line defects and 2D specific topological defects are considered. Key features of the different defect types are illustrated and discussed with selected prototypical examples.