摘要
In this study, Al/TiO2/Al2O3/p-Si was fabricated as a gas sensor. TiO2 and Al2O3 were grown by Atomic Layer Deposition method. The prepared film was tested in various gas concentrations at different operating temperatures ranging between 27 ℃ to 177 ℃. The sensitivity increases with increasing gas concentration and operating temperature which have a direct effect on sensing surface. The gas sensing mechanism could be explained with the surface controlled type based on the change of the electrical conductance of the semiconducting material. This mechanism is controlled by CO molecules and the amount of chemisorbed oxygen on the surface which is associated with temperature. Sample exhibits the basic parameters for gas sensors applications which are good stability, reproducibility and high sensitivity to CO gas which are. In addition, the response and recovery times are measured 19 and 26 s, respectively.
