Hydrogen induced metallization of ZnO (11̅00) surface: Ab initio study

•Hydrogen atoms are strongly adsorbed atop surface oxygen atoms at ZnO surface.•Hydrogen adsorption atop surface Zn atoms is strongly unfavorable.•Hydrogen atoms are shallow donors leading to surface metallization above critical coverage.

Results of first principles hybrid calculations are presented for hydrogen atoms adsorbed upon non-polar ZnO (11̅00) surface. The energy of surface atomic relaxation, H adsorption energy, electronic density redistribution and modification of the electronic structure are discussed. It is shown that hydrogen is adsorbed mainly on the surface oxygen ions and forms a strong bonding with them (2.7 eV). Adsorption of hydrogen on the surface zinc ions is energetically unfavorable (− 4.4 eV). It also shown that surface hydrogen atoms are very shallow donors, thus, contributing to the electronic conductivity, and ZnO metallization.