Improved gas sensing in spray deposited tin oxide thin films by copper doping

Abstract

Non-stoichiometric tin oxide (SnO2−x) thin films are extensively used as gas sensors because of the availability of oxygen vacancies accompanied by other factors. One of the ways to achieve better sensor performance is the incorporation of suitable additives in to the base material. Further, a control over film morphology, vacancy contribution, size and shape of the crystallites can be achieved by the addition of dopant in proper amount. In the present work, Copper (Cu) doped SnO2 thin films are prepared via nebulizer assisted spray deposition method. Structural characterization via X-Ray diffraction (XRD) and morphological characterization via Field Emission Scanning Electron Micrograph (FESEM) have been done. The gas sensing properties are investigated. 0.1 wt. % Cu doped SnO2 thin film shows enhanced sensing performance of 91.1 % with good response. An effort has been put forward to investigate into the sensing mechanism via Raman analysis.