Possible approach to fabricate p-type ZnO through the Be–N codoping method: First-principles calculations

An ab initio calculation based on density functional theory is applied to study Be–N codoped ZnO and the possible complexes are discussed. The calculated results show that the substitutional N defect at the O site (NO) easily binds with the interstitial Be (Bei), rather than the substitutional Be defect at the Zn site (BeZn). This indicates that 4BeZn–NO complex is not a stable acceptor and is unlikely to form. Fortunately, Bei–3NO is of high structural stability and its transition energy is very low due to the impurity band caused by the Bei–2NO passive complex. Therefore, Bei–3NO can serve as a stable source of p-type conductivity. In addition, it is also suggested that Be–N codoped p-type ZnO can be prepared under Zn-rich condition because Bei–3NO has the lowest formation energy in this environment.