Role of surface properties of MoO3-doped SnO2 thin films on NO2 gas sensing

Abstract The role of surface morphology of MoO 3 -doped SnO 2 thin film on the gas sensing properties is analyzed. SnO 2 thin films doped with 1, 3, 5 and 10 wt% MoO 3 are prepared by sol–gel spin coating process. Structural and morphological properties are studied using glancing angle X-ray diffractometer, atomic force microscopy, transmission electron microscopy and high resolution transmission electron microscopy. Energy dispersive X-ray analysis and X-ray photoelectron spectroscopy studies are used for chemical analysis. A good correlation is found between the characteristics of the surface and gas sensing properties of these films. MoO 3 addition is found responsible for increase in acidic nature of films which in turn increases their sensitivity and selectivity towards NO 2 gas.