Nanostructured tin oxide films: Physical synthesis, characterization, and gas sensing properties.

Nanostructured tin oxide (SnO) films are synthesized using physical method i.e. thermal evaporation and are further characterized with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy measurement techniques for confirming its structure and morphology. The chemiresistive properties of SnO films are studied towards different oxidizing and reducing gases where these films have demonstrated considerable selectivity towards oxidizing nitrogen dioxide (NO) gas with a maximum response of 403% to 100ppm @200°C, and fast response and recovery times of 4s and 210s, respectively, than other test gases. In addition, SnO films are enabling to detect as low as 1ppm NO gas concentration @200°C with 23% response enhancement. Chemiresistive performances of SnO films are carried out in the range of 1-100ppm and reported. Finally, plausible adsorption and desorption reaction mechanism of NO gas molecules with SnO film surface has been thoroughly discussed by means of an impedance spectroscopy analysis.