“…Thus far, several experimental [9][10][11][12] and theoretical investigations [13][14][15] to obtain p-type ZnO have been reported. In recent years, P [16], N [17], As [18], Sb [19], Ag [20], Al-N co-doped [21] and Li-N co-doped [22] have been studied extensively as promising dopants for p-type ZnO. The introduction of these dopants and defect complexes during fabrication has been reported to change the type of conductivity, as well as the optical and electrical properties.…”