Enhanced NO2 gas sensing performance of Gd/Li co-doped ZnO thin films

Abstract

In this paper, we demonstrate pure, Gd-doped, and Gd/Li co-doped ZnO nanostructures for NO2 gas sensing applications fabricated via the sol–gel spin coating route. The synthesized samples are examined through various characterization techniques to evaluate their physical and chemical properties. The gas sensing performance of all deposited samples was investigated at different temperatures (150–240 C) towards 75 ppm of NO2 gas. Among them, the Gd/Li codoped ZnO sample shows remarkable NO2 gas sensing performance of 55.18 at a working temperature of 210 C. Also, the gas sensitivity of Gd/Li: ZnO towards various toxic gases, including Cl2, NH3, NO, and NO2, were studied and appeared most selective towards NO2 gas. A possible NO2 gas sensing mechanism was discussed and correlated with structural, morphological, electrical, and spectral studies