A Novel Theoretical Model For Semiconductor Oxide Gas Sensor

A new constitutive equation for the gas sensitivity of n-type semiconductor oxide thin film gas sensor has been proposed here based on a single-crystal model. The derived constitutive equation shows the dependence of the gas sensitivity on various critical parameters such as nanocrystallite size, space-charge-layer thickness, reducing gas concentration, bulk charge-carrier-concentration, surface-density of states, oxygen-ion-vacancy concentration, operating temperature, and film thickness. The present theoretical model is applicable to all n-type semiconductor oxides gas sensors. © 2005 Materials Research Society