Point defects in sputtered NiO films

The dominant point defects in p-type NiO films were determined by analyzing the coordination number (CN) change with various annealing temperatures and the composition profile of double-layer films deposited individually in oxygen and in argon atmospheres. The results show that the nonstoichiometry of sputtered NiO film is determined by the number of nickel atoms rather than by the number of oxygen atoms. It is concluded that nickel vacancies are the dominant point defects that result in the electrical conductivity of NiO films.