Gas sensor

Abstract

A field effect gas sensor (1) for detection of at least one non-hydrogen containing substance in a gas comprising hydrogen or hydrogen-containing substances. The field effect gas sensor comprises a semiconductor layer (2,3) having a surface, at least one ohmic contact (8) contacting the semiconductor (3), a first electron insulating layer (7) covering at least a part of the surface of the semiconductor layer, a second insulating layer (11) comprising a material substantially chemically inert to hydrogen or hydrogen-containing substances, the second insulating layer contacting at least one of the first electron insulating layer (7) and the semiconductor layer (3), at least one electrical contact (12) contacting the second insulating material (11) and comprising a conducting, semi-conducting and / or ion conducting layer. The field effect gas sensor is configured so interaction of the at least one non-hydrogen containing substance with at least part of the at least one electrical contact affects the work function of the conducting, semi-conducting and / or ion conducting layer (12) and / or the electric field in the semiconductor layer (3) in such way that the current-voltage (I-V) or the capacitance-voltage (C-V) characteristics of said field effect gas sensor are changed, wherein the change in I-V or C-V characteristics provide information about the presence of said at least one non-hydrogen containing substance in said gas. Use of the field effect gas sensor for EGR (Exhaust Gas Recirculation) applications. Use of a material substantially chemically inert to hydrogen in a field effect gas sensor.

Description

technical field [0001] The invention relates to the field of gas sensors. In particular, the invention relates to the field of field effect gas sensors and the detection of at least one non-hydrogen-containing species in a gas comprising hydrogen or a hydrogen-containing species. Background technique [0002] Combustion processes in, for example, automotive internal combustion engines, power plants, district heating plants, steam turbines and space heating installations often result in the emission of substances such as nitrogen oxides, hydrocarbons and carbon monoxide (CO), especially If the process is neither optimized nor controlled. The lack or excess of air during combustion results in either incomplete combustion of the fuel or slow combustion kinetics, which results in incompletely oxidized hydrocarbon species and CO being left in the exhaust or flue gas. Typically, the combustion process also results in the formation of nitrogen oxides and the release of fuel-bound...

AI Technical Summary

Problems solved by technology

Therefore, the possibility of detecting non-hydrogen-containing species with this field-effect sensor is very limited due to the presence of hydrogen and / or hydrogen-containing species in the above-mentioned applications (e.g. in combustion processes)

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