Flicker-Noise Gas Sensor

Solid state gas sensors based on metal oxide compositions (e.g., SnO 2 ) are thought to be the best to meet present day technical and economical requirements. The operating principles of such sensors are based on changes in conductivity of molecules of gases (deoxidizers and oxidants) present in the analyzed air. However, in some cases different gases cause the same change in conductivity, which is a substantial disadvantage of such sensors. The subject of this work is to present research into electrofluctuation (flicker-noise) gas sensors based on silicon, which, unlike the sensors mentioned above, have higher selectivity. The adsorption-induced response of these sensors (noise spectral density versus frequency relation) is a unique identifier of the analyzed gas mixtures. The goal of this work was to study possible ways to increase the adsorption-induced response of such gas-sensing structures based on silicon.