First-principle studies on the conductive behaviors of Ga, N single-doped and Ga–N codoped ZnO

We have performed first-principle calculations on the conductive behaviors of Ga, N single-doped and Ga–N codoped ZnO. According to the results, in the Ga single-doped case, with the comparatively smaller effective masses of electrons and the positive impurity formation energy, the fermi-level shifts upward into the conduction band, thus the n-type ZnO with good conductivity can be obtained. In both the N single-doped and Ga–N codoped cases, the fermi-levels shift downward into the valence band, indicating that p-type ZnO can be obtained by both of the methods. However, the holes’ effective masses in the codoping case are much smaller than those in the N single-doped case, and the formation energy in the codoping case is much larger than that in the N single-doped case, thus the p-type conductivity in the codoping case will be much better for its higher carrier mobility and higher acceptor solubility.