Annealing Effect on the Physical Properties of dc Reactive Magnetron Sputtered Nickel Oxide Thin Films

Nickel Oxide (NiO) thin films have been deposited by dc reactive magnetron sputtering technique on unheated substrates and subsequently annealed from 473 to 673 K. The influence of annealing temperature on the structural, morphological, optical and electrical properties was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectrophotometer and Hall effect studies respectively. The as deposited and annealed films were polycrystalline with preferential growth along (200) plane. The NiO films annealed at 573 K exhibited an optical transmittance of 46% and a direct band gap of 3.70 eV. The electrical resistivity of the films decreased as the annealing temperature increased from 473 to 573 K.