Modulation of the microstructure, optical properties and electrical properties of zinc-doped nickel oxide films via direct current sputtering power

Abstract Zinc-doped NiO (NiO:Zn) films were direct-current-magnetron sputtered on the glass substrates. The modulation of the properties of the films via sputtering powers (P spu ) was especially studied. The conducting transition from p to n type was also proposed in mechanism. The NiO:Zn films are all preferentially 〈111〉 oriented. The films with high P spu almost have small lattice distortion due to the improved crystallization caused by the thermal effect and the Zn element doping. The films begin to exhibit the n-type conduction at 90 W P spu . The conducting transition from p to n type is mainly attributed to the occupation of Ni vacancies by Zn 2+ and the interstitial Zn, and the improved n-type conduction in P spu range of 140 W through 160 W to the increase in content of the interstitial Zn atoms. The absorption edge of the NiO:Zn films remaining at about 3.7 eV is slightly affected by the increase in P spu , showing that the doping of the Zn element in the NiO is not mainly in the form of the Ni vacancies occupying ions.