Synthesis of Nanostructured Al-Doped Nb₂O₅ Thin Films Using DC Sputtering Plasma for the Gas Sensors Applications

Abstract

Nb2O5 is one of the most favorable transparent conducting oxide materials, which is efficiently used in thin film gas sensors especially for reducing gases. In this research, Al-doped Nb2O5 thin films on glass substrates with the DC plasma sputtering method for sensing NH3 and NO2 gases. The effect of thermal oxidation time on morphological, structural properties, and gas sensing properties of Nb2O5: Al thin films are investigated. Annealing was performed at 450 ° C for two hours. The results of X-ray diffraction (XRD) revealed that the structures are amorphous. Surface topography and growth behavior of Al-doped Nb2O5 thin films have an essential role in the optimization of gas sensing properties of these films. Also, atomic force microscopy (AFM) has been used to investigate the surface topography of the obtained films. Obtained results from these analyzes revealed that the films have monoclinic phase and surface topography of Nb2O5:Al thin films affected by Al-doped, the roughness and grain size of the surface increased with the increase in the Al content. Also, the effect of Al-doped on the performance of Nb2O5 thin films gas sensors is investigated. The results indicated that the best response was Nb2O5 film of NH3 gas and Nb2O5:1%Al of NO2 gas.