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

► NO and NZn-2Oi are deep acceptors, thus they cannot contribute much to p-type conductivity. ► NZn-2VZn has a high formation energy at the VBM, rendering it unlikely to contribute to the p-type conductivity. ► NZn, (N2)O and (NO)O will heavily compensate the p-type doping of ZnO. ► These results raise serious questions about the feasibility of nitrogen as a p-type dopant.