The Pt-doped SnO₂ thin film detector sensitivities for different gases including the propane, carbon dioxide, acetone, and oxygen have been investigated incorporating the structural evolution of the thin film. The crystallographic structure of the SnO₂ layer significantly varied with increasing the Pt concentration and grain size of the film decrease with Pt content. The highest gas sensitivity of the films is exhibited for the oxygen gases. In addition, the oxygen sensitivity of the sensors increases with the Pt concentration up to a specific operating temperature. This variation may be due to the different contributions of the spillover and Fermi energy control mechanisms to sensor sensitivities. The present results have depicted that the sensor design should be carefully configured to promote the sensing responses of the gas sensors.

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