GAS SENSOR

• US 20190317036A1
• Filed: 10/18/2017
• Published: 10/17/2019
• Est. Priority Date: 10/18/2016
• Status: Active Application

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Sankarraj, Anand Venkatesh, Follett, Gary, Fillmore, Robert L., Evju, Jon K.
• Application Number:
  US16/343,156
• Publication Number:
  US 20190317036A1
• Time in Patent Office: Days
• CPC Class Codes: C23C 14/06 characterised by the coating material C23C14/0021 , C23C14/04 take precedence
• CPC Class Codes: C23C 14/0623 Sulfides, selenides or tellurides
• CPC Class Codes: C23C 14/0629 of zinc, cadmium or mercury
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/081 of aluminium, magnesium or beryllium
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/087 of copper or solid solutions thereof
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: G01N 27/125 Composition of the body, e.g. the composition of its sensitive layer
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies
• CPC Class Codes: G01N 33/0036 Specially adapted to detect a particular component all the other sub-groups of G01N33/0004 take precedence

Abstract

A gas-sensing element includes a gas-sensing surface of transition metal-doped metal oxide semiconductor of a first metal (particularly tin oxide) over a body of the metal oxide semiconductor. The gas-sensing element includes an auxiliary component of: (1) internally-disposed second metal (particularly copper, gold or silver) disposed in the gas-sensing element between the body and the gas-sensing surface, or (2) a metal chalcogenide (particularly sulfide or sulphide) disposed at the gas-sensing surface or internally disposed in the gas-sensing element between the body and the gas-sensing surface that stabilizes the second metal at the gas-sensing surface.

Claims

1. A gas-sensing element, comprising:

a body comprising a semiconductor that is a metal oxide of a first metal;

a gas-sensing surface over the body, comprising metal oxide semiconductor of the first metal and a dopant comprising a second metal that is a transition metal and is different than the first metal; and

an auxiliary component comprising;

(1) internally-disposed second metal disposed in the gas-sensing element between the body and the gas-sensing surface, or

(2) a metal chalcogenide disposed at the gas-sensing surface or internally disposed in the gas-sensing element between the body and the gas-sensing surface adjacent to the gas-sensing surface.

2. The gas-sensing element of claim 1, wherein the auxiliary component comprises:

(1) internally-disposed second metal disposed in the gas-sensing element between the body and the gas-sensing surface, and metal oxide semiconductor of the first metal disposed between the internally-disposed second metal and the gas-sensing surface adjacent to the gas-sensing surface.

3. The gas-sensing element of claim 2, wherein, further comprising metal oxide semiconductor of the first metal disposed between the internally-disposed second metal and the gas-sensing surface.

4. The gas-sensing element of claim 2, comprising a plurality of alternating deposits of the metal oxide semiconductor of the first metal and deposits of the second metal, disposed in the gas-sensing element between the body and the gas-sensing surface.

5. The gas-sensing element of claim 1, wherein the auxiliary component comprises:

(2) a metal chalcogenide disposed at the gas-sensing surface or internally disposed in the gas-sensing element between the body and the gas-sensing surface adjacent to the gas-sensing surface, that stabilizes the second metal at the gas-sensing surface.

6. The gas-sensing element of claim 5, wherein the metal chalcogenide is disposed at the gas-sensing surface.

7. The gas-sensing element of claim 5, wherein the metal chalcogenide is internally disposed in the gas-sensing element between the body and the gas-sensing surface adjacent to the gas-sensing surface, which stabilizes the second metal at the gas-sensing surface.

8. The gas-sensing element of claim 5, wherein the metal chalcogenide comprises a metal sulfide.

9. The gas-sensing element of claim 1, wherein the second metal comprises one or more group 5 to group 11 transition metals.

10. The gas-sensing element of claim 1, wherein the first metal comprises aluminum, bismuth, cadmium, cerium, chromium, cobalt, copper, iron, gallium, indium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium or zinc.

11. The gas-sensing element of claim 1, wherein the first metal comprises tin and the second metal comprises copper.

12. A gas sensor comprising the gas-sensing element of claim 1 disposed between electrodes connected by a voltage-measuring circuit, current-measuring circuit, resistance-measuring circuit, impedance-measuring circuit, or conductance-measuring circuit.

13. The gas sensor of claim 12, wherein the resistance-measuring circuit comprises a signal processor calibrated to determine hydrogen sulfide concentration based on measured resistance at the gas-sensing surface.

14. A method of using the gas sensor of claim 11, comprising exposing the gas-sensing surface to a gas to be tested, and measuring resistance of the gas-sensing element between the electrodes to determine a presence or concentration of a gas component.

15. The method of claim 14, wherein the gas component comprises hydrogen sulfide.

16. A method of making a gas-sensing element, comprising disposing a transition metal dopant comprising a second metal that is a transition metal at a surface of a semiconductor that is a metal oxide of a first metal, and:

(1) disposing second metal in the gas-sensing element between the surface and a body of the metal oxide semiconductor of the first metal, or (2) disposing a metal chalcogenide on top of the doped surface or in the gas-sensing element between a body comprising the metal oxide semiconductor of the first metal and the doped surface adjacent to the doped surface.

17. The method of claim 16, wherein (1) comprises depositing second metal over the body, depositing metal oxide semiconductor of the first metal over the deposited second metal, and depositing second metal over the deposited metal oxide semiconductor of the first metal.

18. The method of claim 16, wherein (1) comprises alternately depositing second metal and metal oxide semiconductor of the first metal to form a plurality of alternating deposits of second metal and metal oxide semiconductor of the first metal between the body and the doped surface.

19. The method of claim 16, wherein (2) comprises disposing the metal chalcogenide on top of the doped surface.

20. The method of claim 16, wherein (2) comprises disposing the metal chalcogenide between the body of metal oxide semiconductor of the first metal and the doped surface adjacent to the doped surface.