Ni-doped SnO2 thin films for NO2 gas sensing application

Abstract

Tin (IV) oxide (SnO2) and Nickel doped tin oxide thin films (NSO) were deposited by spray pyrolysis technique from an aqueous solution for gas sensing application. X-Ray Diffraction (XRD) analysis confirmed the tetragonal structure of pure SnO2 and Ni-doped films. The lattice parameters calculated for (NSO) decreased with increasing the Ni ratio. The average crystallites sizes deduced from Scherrer formula are between 5 and 8 nm.The FE-SEM reveals that films surface is response relatively homogeneous with good coverage of the substrate surface without any cracks. Increasing the Ni content causes the appearance of cauliflower aggregation structures of around 100 nm diameter and be denser at a high percentage of Ni. The Raman spectroscopy indicates the formation of SnO2 nanostructures and increases defects and vaccines by increasing the Ni contents. The NO2 gas sensors based on the NSO nanostructure sensor performance were enhanced toward NO2 at 100 °C with the best Ni ratio of 20 mol % compared to other tested ratios from 0 to 15%. The proposed device based on the NSO thin films is a low-cost sensor with good specifications.