Influence of nitrogen doping on properties of NiO films

Undoped and nitrogen (N) doped nickel oxide (NiO) thin films were deposited onto glass substrates using a simplified spray pyrolysis technique with two different doping levels of N (10 and 20 at-%). The effects of N doping level on the structural, electrical and optical properties were studied and reported. From the structural studies, it is found that the preferential orientation changed from (111) to (200) for higher concentrations. The optical studies revealed that the average optical transmittance and optical band gap decreased (from 3 center dot 5 to 3 center dot 4 eV) due to N doping. The electrical resistivity decreased by one order (from 3 center dot 84E+03 Omega cm to 5 center dot 38E+02 Omega cm) in the case of higher doping of N. The defects generated by N doping were analysed using the photoluminescence studies. The size of the grains decreased due to N doping as seen from SEM studies.