p-TYPE CHEMORESISTIVE GAS SENSOR BASED ON Pt-MODIFIED NiO SPUTTERED THIN FILMS FOR THE DETECTION OF HYDROGEN ELECTRONIC NOSE

摘要

In this paper, we present the results concerning the Pt surface modification of NiO thin films deposited by dc reactive magnetron sputtering. Pt very thin overlayers (about 3 and 5 nm thick) have been sputtered on the top of NiO samples. The samples have been characterised by XRD, SEM and AFM. 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.