In assisted realization of p-type C-doped ZnO: A first-principles study

C mono-doped and C–In co-doped ZnO are investigated by the first-principles calculations. It is found that the C mono-doped ZnO is p-type with hole carriers locating nearby valence band maximum. Furthermore, a shallower C acceptor energy level appears in the band gap after incorporating In into C-doped ZnO system. Meantime, compared with C mono-doped ZnO, C–In co-doped ZnO has a lower formation energy, correspondingly a higher chemical stability, and thus to enhance the incorporation efficiency of C. These results suggest that C–In co-doping method provided an efficient technique for realizing p-type ZnO.