# US 10,371,658 B2 · Gas sensor and sensor apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,371,658 B2
- Document ID: US10371658B2
- Status: Granted
- Kind: B2
- Application number: 15/682,867
- Filed: 2017-08-22
- Published: 2017-12-07
- Granted: 2019-08-06
- Earliest claimed: 2015-03-10
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Satoru Momose; Osamu Tsuboi; Kazuaki Karasawa
- Web page: https://patentgrep.com/patent/US10371658B2

## CPC

- 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}
- G01N 27/4141: {specially adapted for gases}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## 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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 1)

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

### Claim 4 (depends on 1)

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.

### Claim 5 (depends on 1)

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.

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 1)

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.

### Claim 8 (depends on 7)

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

### Claim 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.