Sputter Power Influenced Structural, Electrical, and Optical Behaviour of Nanocrystalline CuNiO2 Films Formed by RF Magnetron Sputtering

Abstract

Copper nickel oxide (CuNiO2) films were deposited on glass and silicon substrates using RF magnetron sputtering of equimolar Cu50Ni50 alloy target at different sputter powers in the range of 3.1–6.1 W/cm2. The effect of sputter power on the chemical composition, crystallographic structure, chemical binding configuration, surface morphology, and electrical and optical properties of CuNiO2 films was investigated. The films formed at sputter power of 5.1 W/cm2 were of nearly stoichiometric CuNiO2. Fourier transform infrared spectroscopic studies indicated the presence of the characteristic vibrational bands of copper nickel oxide. The nanocrystalline CuNiO2 films were formed with the increase in grain size from 75 to 120 nm as the sputter power increased from 3.1 to 5.1 W/cm2. The stoichiometric CuNiO2 films formed at sputter power of 5.1 W/cm2 exhibited electrical resistivity of 27 Ωcm, Hall mobility of 21 cm2/Vsec, and optical bandgap of 1.93 eV.