Kinetics of gas response to reducing gases of SnO2 films, deposited by spray pyrolysis

✍ Scribed by G. Korotcenkov; V. Brinzari; V. Golovanov; Y. Blinov

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 132 KB
• Volume: 98
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2003.08.022

✦ Synopsis

The present paper is devoted to systematic measurements of SnO 2 gas response to reducing gases in transient mode. SnO 2 films were deposited by spray pyrolysis from SnCl 4 -water solution. The influence of operation temperature (25-500 • C) on gas response (S) to CO and H 2 (0.1-0.5%), response time (τ), shape of S(T) curves, and activation energy of τ(1/kT) dependencies is discussed. Three operating temperature ranges with different activation energies of 0.3-0.38, 0.6-0.7, and 1.1-1.4 eV were selected on τ(1/kT) dependencies. The mechanism of oxygen and water influence on gas sensing characteristics of SnO 2 films has been proposed. It was concluded that adsorption/desorption processes of molecular oxygen, hydroxyl groups, and atomic oxygen have dominant influence on electro-physical and gas sensing characteristics of SnO 2 films in the temperature ranges of 25-150; 200-400 and >450 • C, respectively.