Microstructural characterization of nickel hydroxide films deposited using an ammonia-induced method and subsequently calcined nickel oxide films

Nickel hydroxide films were deposited using a facile ammonia-induced method. The deposited films were composed of stacking structures without using templates or surfactants. The microstructures of the deposited films and subsequently calcined NiO films were characterized using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrical properties were also investigated. The deposited films consisted of triangular stacks of single crystal hexagonal Ni(OH)2 and their microstructures were highly affected by the substrate type. A preference for orientation along the (001) plane was observed in the Ni(OH)2 films deposited onto indium tin oxide (ITO) substrates with a high texture coefficient of 4.5. These characteristics were not found in Ni(OH)2 films deposited onto glass and silicon substrates. Calcined films did not show a strong preference in orientation and were found to be n-type NiO.