Comprehensive investigations on the feasibility of nitrogen as a p-type dopant in ZnO

It is controversial whether nitrogen can dope ZnO p-type or not. According to our first-principles calculations, no defects or defect complexes can result in p-type conductivity in ZnO. NO and NZn–2Oi have deep transition levels, while NZn–2VZn has a high formation energy at the valence band maximum (VBM), rendering all of them unlikely to contribute to the p-type conductivity. Besides, NZn will heavily compensate the p-type doping of ZnO in O-rich conditions, while (N2)O and (NO)O will do that in Zn-rich conditions. All these results raise serious questions about the feasibility of nitrogen as a p-type dopant.