Oxygen sensor used in combustion plants and automobile engines

摘要

An oxygen gas sensor has a cerium oxide (CeO2) cover layer on its oxygen sensitive semiconductor layer. Preferred Features: The CeO2 cover layer covers the sensor surfaces exposed to the gas mixture and is doped with gadolinium to increase its ion conductivity. The cover layer may be associated with electrodes for short-circuiting and/or for providing a pump current and may be separated from the oxygen sensitive semiconductor layer by a porous electrically insulating layer of aluminum oxide. The oxygen sensitive semiconductor layer is associated with electrodes for detecting electrical property changes resulting from variations of oxygen content in the gas mixture. The semiconductor layer may form two different regions, especially p-doped and n-doped regions, on opposite sides of a flat support substrate. All the sensor materials are designed for use at greater than or equal to 600 deg C, especially up to greater than or equal to 1100 deg C.