Dipolar and charge transfer effects on the atomic stabilization of ZnO polar surfaces

We present a DFT study of ZnO polar surfaces, and discuss our results in terms of charge redistribution and polarization field. Beyond some refinements in the methodology that allow to take fully in account the electrostatic contribution of polar compounds, we describe in a unified way the electronic properties of short range reconstructions at these polar surfaces. Our analysis allows to interpret as fictitious the metallicity of clean (1×1) surfaces, and to describe the stabilizing role of surface defects and hydroxylation.