Annealing-assisted SnO2 Thin Film for Selective Hydrogen Gas Sensor

Abstract

Today, monitoring and classification of hydrogen gas by metal oxide-based sensors are widely studying to improve their selectivity and stability. In present work, hydrogen sensing properties of magnetron sputtered deposited pure SnO2 thin films have been studied. The pure SnO2 thin film was deposited on glass substrate and as-deposited film was annealed at 450 °C for 6 hrs. The annealed SnO2 thin film has crystalline tetragonal structure, granular surface morphology and non-stoichiometry elemental composition of tin and oxygen vacancies. A higher gas sensing response is obtained for annealed SnO2 thin film as compare to as-deposited SnO2 thin film.A limit of detection (LOD) ~175 ppb is estimated for annealed SnO2 thin film-based sensor. This sensor exhibits fast response and recovery time of 42 s/52 s for 50 and 500 ppm hydrogen gas, respectively. The sensor is found highly selective towards H2 gas in compare to different gases such as methane, carbon monoxide and nitrogen dioxide.