Analysis of Non-Steady Stage in SAW Gas Sensors with Semiconducting Sensor Layers

The profile of the gas concentration in the sensor layer can be expressed as a polynomial function involving the diffusion coefficient (D(K)), semiconductor film thickness (h), rate constant (k), gas concentration outside the semiconductor film (C(s)). Before reaching a steady state of the concentration profile, its behavior depends on a few factors as the distance from the piezoelectric surface, the rate constant, the thickness of the layer and the diffusion constant and time. We are going to simulate temporary processes in the semiconductor sensor film in the surface acoustic wave gas sensor system and to describe the influence on relative changes of the surface acoustic wave velocity. The numerical results basing on the code written in Pyton, are described and analyzed.