Gas sensor

• US 5,824,271 A
• Filed: 03/13/1997
• Issued: 10/20/1998
• Est. Priority Date: 09/14/1994
• Status: Expired due to Fees

• Current Assignee: Epcos AG (TDK Corporation)
• Original Assignee: Siemens AG
• Inventors: Frank, Joachim, Meixner, Hans, Fleischer, Maximilian
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Carrillo, Sharidan
• Application Number:
  US08/809,264
• Time in Patent Office: 586 Days
• Field of Search: 422/94, 422/95, 422/96, 422/97, 422/98, 436/149, 436/153, 436/132, 436/134, 436/141, 73/23.31, 73/31.06, 73/23.2, 338/34
• US Class Current: 422/98
• CPC Class Codes: G01N 27/12 of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid , for detecting components in the fluid
• CPC Class Codes: G01N 33/0031 comprising two or more sensors, e.g. a sensor array
• CPC Class Codes: Y10T 436/205831 Carbon monoxide only
• CPC Class Codes: Y10T 436/208339 Fuel/air mixture or exhaust gas analysis
• CPC Class Codes: Y10T 436/214 Acyclic [e.g., methane, octane, isoparaffin, etc.]

Abstract

A substrate carrying a first electrode and a second electrode, the first and second electrodes being disposed adjacent to one another, the first electrode being disposed between the substrate and a gas-sensitive component, the gas sensitive component comprising an n-type semiconductor, the gas-sensitive component having a resistance that is gas-dependent and temperature-dependent, and the second electrode being disposed between the substrate and a non-gas-sensitive component, the non-gas-sensitive component comprising a n-type semiconductor and a p-type semiconductor, the non-gas-sensitive component having a resistance that is temperature-dependent and that is not gas-dependent and wherein the n-type semiconductor of the non-gas-sensitive component is Ga₂ O₃ and the p-type semiconductor of the non-gas-sensitive component is ZrO₂.

Claims

1. A gas sensor comprising:

a substrate carrying a first electrode and a second electrode, the first and second electrodes being disposed adjacent to one another,

the first electrode being disposed between the substrate and a gas-sensitive component, the gas sensitive component comprising an n-type semiconductor, the gas-sensitive component having a resistance that is gas-dependent and temperature-dependent, and

the second electrode being disposed between the substrate and a non-gas-sensitive component, the non-gas-sensitive component comprising a n-type semiconductor and a p-type semiconductor, the non-gas-sensitive component having a resistance that is temperature-dependent and that is not gas-dependent.

2. The gas sensor of claim 1 wherein the n-type semiconductor of the gas-sensitive component is Ga₂ O₃.

3. The gas sensor of claim 1 wherein the n-type semiconductor of the non-gas-sensitive component is Ga₂ O₃.

4. The gas sensor of claim 1 wherein the n-type semiconductor of the non-gas-sensitive component is Ga₂ O₃ and the p-type semiconductor of the non-gas-sensitive component is ZrO₂.

5. The gas sensor of claim 1 wherein the n-type semiconductor of the non-gas-sensitive component further comprises at least one layer of a n-type semiconductor material and the p-type semiconductor of the non-gas-sensitive component further comprises at least one layer of a p-type semiconductor material.

6. The gas sensor of claim 5 wherein the n-type and p-type semiconductor layers are heat-treated at temperatures ranging from about 900°

C. to about 1050°

C.

7. The gas sensor of claim 1 wherein the first electrode comprises an interdigital component.

8. The gas sensor of claim 1 wherein the second electrode comprises an interdigital component.

9. The gas sensor of claim 1 wherein the gas sensor characterized as being able to detect detects reducing gases at temperatures ranging from about 600°

C. to about 850°

C.

10. The gas sensor of claim 1 wherein the gas sensor detects oxygen at a temperature of about 950°

C.