Multifunctional heterojunction metal oxide gas sensor
AssigneeInternational Business Machines Corporation
InventorAndrea Fasoli
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Abstract
A method of identifying a gas is provided. The method includes providing a gas sensor device comprising at least two stacked metal oxide layers, wherein a change in conductance of the gas sensor device in a presence of a gas varies with a temperature of the stacked metal oxide layers. The method includes bringing the gas into proximity with the stacked metal oxide layers. The method also includes measuring the conductance of the gas sensor device when the gas is in proximity with the stacked layers at multiple temperatures to generate a temperature-conductance profile. The method also includes identifying a gas of interest based on the temperature-conductance profile.
Claims19
A method of identifying a gas, the method comprising:
- providing a gas sensor device comprising two stacked metal oxide layers having different material compositions, wherein a change in conductance of the gas sensor device in a presence of a gas varies with a temperature of the metal oxide layers;
- bringing the gas into proximity with the metal oxide layers;
- measuring the conductance of the gas sensor device when the gas is in proximity with the metal oxide layers at multiple temperatures to generate a temperature-conductance profile;
- and
- identifying a gas of interest based on the temperature-conductance profile,
- wherein (i) over a first portion of a temperature range, the gas sensor device conductance is characteristic of a first one of the metal oxide layers when used alone, and
- wherein (ii) over a second portion of the temperature range that is different from the first portion of the temperature range, the gas sensor device conductance is characteristic of a second one of the metal oxide layers when used alone.
A gas sensor device comprising:
- a substrate;
- at least two electrodes formed on the substrate;
- a first metal oxide layer formed on the substrate and the electrodes;
- and
- a second metal oxide layer formed on the first metal oxide layer, the first metal oxide layer having a different material composition than the second metal oxide layer,
- wherein a change in conductance of the gas sensor device in a presence of a gas varies with a temperature of the first and second metal oxide layers,
- wherein (i) over a first portion of a temperature range, the gas sensor device conductance is characteristic of the first metal oxide layer when used alone, and
- wherein (ii) over a second portion of the temperature range that is different from the first portion of the temperature range, the gas sensor device conductance is characteristic of the second metal oxide layers when used alone.
Dependencies are inferred from the claim text.