Origins of the doping asymmetry in oxides : hole doping in NiO versus electron doping in ZnO

ABSTRACT: The doping response of the prototypical transparent oxides NiO (p-type), ZnO (n-type), and MgO (insulating) is caused by spontaneous formation of compensating centers, leading to Fermi-level pinning at critical Fermi energies. We study the doping principles in these oxides by first-princip...