Effect of (Co, N) co-doping of p-type ZnO on electronic and magnetic properties by DFT+U studies

This study presents the calculation of (Co-N) co-doped ZnO in the wurtzite structure of 32 atoms, a density functional calculation and a theoretical analysis of the electronic and magnetic properties are investigated using the Full-Potential Linearized Augmented Plane Wave (FPLAPW) method, implemented in WIEN2k package. We have used two approaches LSDA and LSDA+U to analyze and correct the density of state, and to understand the Co and N influence on p-type ZnO at different concentrations, i.e., their bonding with nitrogen is also determined. The results prove that ZnO doped with two N concentrations of 6.25% and 12.5% is p-type, semi-metallic and ferromagnetic caused by the strong hybridization effect between N 2p and O 2p states, with a full magnetic moment of 1μ_B and 0.31μ_B, respectively. As for co-doped ZnO with Co and two concentrations of N, the LSDA+U approximation shows that the total magnetic moment increases with the N concentration from 3.92 to 4.51μ_B due to hybridization effects between Co 3d and N 2p states.