The effect of copper doping on the optical and electrical properties of nickel oxide thin films deposited by spin coating technique

In this work, we have synthesized and successfully prepared the nickel oxide and the copper doped nickel oxide thin films by spin coating. We have investigated the effect of copper doping on the optical and electrical properties of nickel oxide thin films. The energy band gap values reduced with increase in copper concentration which indicate that copper doped nickel oxide (Cu:NiO) is suitable for optoelectronic application. The average transmission of the copper doped nickel oxide film is decreased in the visible wavelength range from 95 to 75%. This decrease can be attributed to the increase in the scattering of the incident light resulting from the increase in surface roughness of copper doped nickel oxide film. The PL response shows an increase of intensity with the increase of copper concentration that linked to the increase of defect levels and confirms the incorporation of Cu2+ in the nickel oxide film. The electrical properties of the FTO/NiO/Al and FTO/Cu:NiO (5%, 10%)/Al structures device showed that charge mobility and electrical conductivity were improved with copper doping. These results indicate that copper is an excellent dopant for NiO.