First-principle study on the effect of high Ag–2N co-doping on the conductivity of ZnO

The geometric structure, band structure (BS) and density of state (DOS) of pure and p-type co-doping wurtzite ZnO have been investigated by the first-principle ultrasoft pseudopotential method with the generalized gradient approximation. These structures induce fully occupied defect states above the valence-band maximum of doped ZnO. The calculation results show that in the range of high doping concentration, when the co-doping concentration is more than a certain value, the conductivity decreased with the increase of co-doping concentration of Ag–2N in ZnO. Our findings suggest that co-doping of Ag–2N could efficiently enhance the N dopant solubility and is likely to yield better p-type conductivity.