Metal oxide semiconductor gas sensor

Patent metadata

Field	Value
Publication number	US-12196698-B2
Application number	US-202217984758-A
Country	US
Kind code	B2
Filing date	Nov 10, 2022
Priority date	Nov 10, 2022
Publication date	Jan 14, 2025
Grant date	Jan 14, 2025

Abstract

A metal oxide semiconductor gas sensor includes a first electrode, a second electrode, and a sensing layer in contact with the first electrode and the second electrode. The sensing layer includes SnO 2 and WO 3 . A cross section of the sensing layer has an average porosity of 16.0% or more and 22.0% or less. SnO 2 occupies 60 vol % or more and 80 vol % or less and WO 3 occupies 20 vol % or more and 40 vol % or less in the sensing layer provided that pores are not counted as part of the sensing layer.

First claim

What is claimed is:

1. A metal oxide semiconductor gas sensor comprising:
a first electrode;
a second electrode; and
a sensing layer in contact with the first electrode and the second electrode; wherein
the sensing layer includes SnO 2 and WO 3 ,
a cross section of the sensing layer has an average porosity of 16.0% or more and 22.0% or less, and
SnO 2 occupies 60 vol % or more and 80 vol % or less and WO 3 occupies 20 vol % or more and 40 vol % or less in the sensing layer provided that pores are not counted as part of the sensing layer.

2. The metal oxide semiconductor gas sensor according to claim 1 , wherein φ f −φ n ≥1.0 is satisfied, in which φ n (%) is the average porosity of a region of the sensing layer closest to the first electrode and the second electrode, and φ f (%) is the average porosity of a region of the sensing layer farthest from the first electrode and the second electrode, provided that the sensing layer is divided into three substantially equal regions in a thickness direction of the sensing layer.

3. The metal oxide semiconductor gas sensor according to claim 1 , wherein a cross section of the sensing layer has an average pore size of 70 nm or more and 150 nm or less.

4. The metal oxide semiconductor gas sensor according to claim 1 , wherein the sensing layer has a thickness of 1.0 μm or more.

Assignees

• Tdk Corp

Inventors

• Ishikura Tomokazu
• Fujita Kazutaka
• Masaoka Raitaro

Classifications

• G01N27/125 Primary

  Composition of the body, e.g. the composition of its sensitive layer · CPC title

• G01N27/127 Primary

  comprising nanoparticles · CPC title