Gas sensor
AssigneeJapan Science and Technology Agency
InventorsYutaka Majima, Trong Tue Phan
Life of this patent
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Abstract
To provide a gas sensor with fast response and high sensitivity to oxygen gas. Disclosed is a gas sensor 100 including: a substrate 10; a first pad electrode 12A and a second pad electrode 12B; a nanowire 14 made of a specific metal; and an oxide layer 16 made of a high-resistance semiconductor that is an oxide of a metal different from a metal constituting the nanowire 14. The first pad electrode 12A and the second pad electrode 12B are formed on or above the substrate 10. The nanowire 14 connects the first pad electrode 12A and the second pad electrode 12B and is formed on or above the substrate 10. The oxide layer 16 is formed in contact with the nanowire 14. This contact between the nanowire 14 and the oxide layer 16 provides fast response and high sensitivity to oxygen gas.
Claims10
A gas sensor comprising:
- a substrate having an insulating surface;
- a first pad electrode and a second pad electrode each formed on or above the insulating surface of the substrate;
- a nanowire connecting the first pad electrode and the second pad electrode and formed on or above the insulating surface of the substrate, the nanowire consisting of at least one selected from the group consisting of platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), iridium (Ir), and alloys thereof;
- and
- an oxide layer in contact with the nanowire, the oxide layer being made of a high-resistance semiconductor that is an oxide of a metal different from a metal constituting the nanowire and at least satisfying one or both of the following conditions:
- (I) being located between the insulating surface of the substrate and the nanowire and in contact with a bottom surface of the nanowire, and (II) being located on the nanowire and in contact with a top surface of the nanowire,
- wherein oxygen gas is detected based on changes in electrical signals detected across the first pad electrode and the second pad electrode with a current flowing across the first pad electrode and the second pad electrode, and
- wherein a first conduction path where carriers pass through the nanowire and a second conduction path where carriers are injected from the nanowire into the oxide layer, travel through the oxide layer, and return to the nanowire are created when the oxygen gas is detected.
A gas sensor comprising:
- a substrate having an insulating surface;
- a first pad electrode and a second pad electrode each formed on or above the insulating surface of the substrate;
- a nanowire connecting the first pad electrode and the second pad electrode and formed on or above the insulating surface of the substrate, the nanowire consisting of at least one selected from the group consisting of platinum (Pt) and alloys thereof;
- and
- an oxide layer in contact with the nanowire, the oxide layer being made of a high-resistance semiconductor that is an oxide of a metal different from a metal constituting the nanowire and at least satisfying one or both of the following conditions:
- (I) being located between the insulating surface of the substrate and the nanowire and in contact with a bottom surface of the nanowire, and (II) being located on the nanowire and in contact with a top surface of the nanowire,
- wherein the high-resistance semiconductor constituting the oxide layer is at least one selected from the group consisting of cerium oxide, tin oxide, and zirconium oxide, and
- wherein gas is detected based on changes in electrical signals detected across the first pad electrode and the second pad electrode with a current flowing across the first pad electrode and the second pad electrode.
Dependencies are inferred from the claim text.