Tube size effect of anodized alumnium oxide template based gas sensor

The sensitivity of the anodized aluminum oxide (AAO) template based semiconductor metal oxide (SMO) gas sensor is closely related to the AAO's tube diameter size. In this work, a well-controlled ring-shaped AAO template is constructed in the simulation software and analyzed regarding its NO2 sensing behavior. For comparison, AAO tubes with different diameters of 500nm, 700nm and 900nm are constructed and the detailed I-Y curve and current density distribution figures are presented. According to the simulation results, it is indicated that the corresponding sensitivity increases from 1.59 to 2.57 as the tube diameter increases for 3×3 matrix. In addition, a uniform current density distribution in 3D surface is found in this template based sensing film together with the increased surface to volume ratio when the diameter is enlarged. Combining the above two reasons, we hereby conclude that AAO template based gas sensor with larger tube diameter can achieve a higher sensitivity due to the tube size effect. This study not only sheds light on the mechanism of performance enhancement with porous gas sensor structure, but also proposes a rational approach and a simulation platform to design this template based chemical/biology sensors with desirable performance.