NiO modified thin films for gas monitoring

In our contribution, we present the results concerning the Pt surface modification of nickel oxide thin films deposited by dc reactive magnetron sputtering. Pt very thin overlayers with a thickness of about 3 and 5 nm have been sputtered on the top of NiO samples. The surface structure and morphology of the samples have been analysed by XRD and by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The electrical responses of the NiO-based sensors towards different H₂ concentration (500-5000 ppm) have been also considered. The Pt modified NiO samples showed an enhancement of the response towards H₂ as compared to the unmodified NiO sample. The thickness of the Pt thin layers seems also an important parameter in determining the properties of the NiO films as H₂ sensors.