Defect formation in chlorine-doped zinc oxide

• Cl-doping in ZnO is inclined to occupy oxygen site.
• Cl-doping is an effective method to eliminate oxygen vacancy.
• ClO could form a donor level in ZnO:Cl.

First-principles pseudopotential calculations have been performed to investigate the chorine-doped zinc oxide. From the calculated results, it is concluded that the ClO is energetically favorable and easy to form under the O-poor condition. Therefore, Cl-doping is an effective method to eliminate the oxygen vacancy in ZnO during the growth. However, the corresponding energy levels of ClO and Cli in band gap are rather deep so that they cannot play a role of donor or acceptor.