Electronic structure of defects and doping in ZnO: Oxygen vacancy and nitrogen doping

Abstract

In the Editor's Choice article of this issue (pp. 2091–2101), Adisak Boonchun and Walter R. L. Lambrecht give an overview of the current understanding of two important defects in ZnO: the oxygen vacancy and nitrogen impurities. While nitrogen substituting on the oxygen site is known to give rise to a deep level unsuitable for p-type doping, the authors propose that a diatomic nitrogen molecule substituting on the Zn site can act as a shallow acceptor. First-principles calculations are used to substantiate this claim. Furthermore the authors present evidence that this defect has in fact already been observed by electron paramagnetic resonance and in photoluminescence but has until now not been fully identifi ed. The incorporation of this defect on different surfaces and the potential impact for solving the notorious p-type doping problem in ZnO are discussed.