Gas sensor and sensor apparatus

Patent metadata

Field	Value
Publication number	US-10371658-B2
Application number	US-201715682867-A
Country	US
Kind code	B2
Filing date	Aug 22, 2017
Priority date	Mar 10, 2015
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A gas sensor includes a p-type semiconductor layer that contains copper or silver cations and contacts with detection target gas, a first electrode that is a Schottky electrode to the p-type semiconductor layer, a high-resistance layer that is provided between the p-type semiconductor layer and the first electrode such that the p-type semiconductor layer and the first electrode partly contact with each other and has resistance higher than that of each of the p-type semiconductor layer and the first electrode, and a second electrode that is an ohmic electrode to the p-type semiconductor layer.

First claim

What is claimed is:

1. A gas sensor, comprising:
a p-type semiconductor layer that contains copper or silver cations and contacts with detection target gas;
a first electrode that is a Schottky electrode to the p-type semiconductor layer;
a high-resistance layer that is provided between the p-type semiconductor layer and the first electrode and has resistance higher than that of each of the p-type semiconductor layer and the first electrode; and a second electrode that is an ohmic electrode to the p-type semiconductor layer,
wherein the high-resistance layer has intermittent defects through which the first electrode directly contacts the p-type semiconductor layer.

2. The gas sensor according to claim 1 , wherein the p-type semiconductor layer and the first electrode are coupled such that a capacitor and Schottky junction are parallel to each other.

3. The gas sensor according to claim 1 , wherein the high-resistance layer is an insulating layer.

4. The gas sensor according to claim 1 , wherein the high-resistance layer is an n-type semiconductor layer having a work function lower than those of the p-type semiconductor layer and the first electrode.

5. The gas sensor according to claim 1 , wherein, when reducing detection target gas contacts with the p-type semiconductor layer, a potential of the second electrode varies in a positive direction.

6. The gas sensor according to claim 1 , wherein the p-type semiconductor layer contains one selected from a group consisting of cuprous bromide, cuprous oxide, silver bromide and silver sulfide.

7. A sensor apparatus, comprising:
the gas sensor according to claim 1 ; and
a detection unit that is coupled to the gas sensor and detects a potential difference between the first electrode and the second electrode of the gas sensor.

8. The sensor apparatus according to claim 7 , wherein the detection unit is a field effect transistor.

9. A gas sensor, comprising:
a p-type semiconductor layer that contains copper or silver cations and contacts with detection target gas;
a first electrode that is a Schottky electrode to the p-type semiconductor layer;
a high-resistance layer that is provided between the p-type semiconductor layer and the first electrode such that the p-type semiconductor layer and the first electrode partly contact with each other and has resistance higher than that of each of the p-type semiconductor layer and the first electrode; and
a second electrode that is an ohmic electrode to the p-type semiconductor layer,
wherein the first electrode and the second electrode contain a metal material having an ionization tendency lower than that of a metal element contained in the p-type semiconductor layer.

Assignees

• Fujitsu Ltd

Inventors

• Momose Satoru
• Tsuboi Osamu
• Karasawa Kazuaki

Classifications

• G01N27/4141 Primary

  specially adapted for gases · CPC title

• G01N27/12 Primary

  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 title