N-type conductivity in oxygen ion implanted nanocrystalline diamond films

Nanocrystalline diamond films were implanted by oxygen ion and annealed under different temperatures. The results show that the oxygen ion implanted nanocrystalline diamond films exhibit n-type conductivity when the annealing temperature is above 800°C. The annealing stimulates the electrical activation of oxygen ion implanted diamond grains and grain boundaries. The origin of n-type conductivity and related mechanisms are discussed.