Selectivity of semiconductor gas sensors

Techniques to Optimize the Selectivity of a Gas Sensor

“…The selectivity allows to the gas sensor detecting the presence of the particular gases in media including other gases, which can also be detected. A reduced quantity of works has been done with the aim of improving the selectivity of gas sensors [1][2][3][4][5][6][7][8][9][10][11][12]. In this paper, the selectivity of a gas sensor is studied with the aim of optimizing the fabrication and design techniques, as well as its performance during its operation.…”

Synthesis and gas sensing property of nanostructured strontium titanate ferrite

“…Several kinds of oxygen adsorbates species, such as O 2 − , O − , and O 2− , are known to chemisorb on the surface of semiconductor metal oxides in air [32,33]. The formation of such oxygen adsorbed species at the surface extracts electrons from the bulk of the metal oxide via several routes [34]: In the case of n-type semiconductor metal oxides, the formation of these oxygen adsorbates builds a space-charge region on the surfaces of the metal oxides grains, caused by electron transfer from the grain surfaces to the adsorbates [31,36,37].…”

“…The resistance of n-type semiconductor gas sensors in air is therefore high, owing to the development of a potential barrier to electronic conduction at each grain boundary [37] , as shown in When the n-type semiconductor sensors is exposed to an atmosphere containing reducing gases such as carbon monoxide, ammonia and hydrogen at elevated temperatures, the oxygen adsorbates are consumed by the reaction shown in equation (2)(3)(4)(5). This establishes a lower steady-state surface coverage of the oxygen adsorbates on the grain surface.…”