Low power consumption type gas sensor and method for manufacturing the same

• US 9,285,332 B2
• Filed: 04/11/2014
• Issued: 03/15/2016
• Est. Priority Date: 12/12/2011
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology
• Original Assignee: Korea Advanced Institute of Science and Technology
• Inventors: Jang, Ho Won, Yoon, Seok Jin, Kim, Jin Sang, Kang, Chong Yun, Choi, Ji Won, Moon, Hi Gyu
• Primary Examiner(s): SHINGLETON, MICHAEL B
• Application Number:
  US14/250,821
• Publication Number:
  US 20140217404A1
• Time in Patent Office: 704 Days
• US Class Current: 1/1
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G01N 27/127 comprising nanoparticles

Abstract

The present disclosure provides a gas sensor including: a substrate; an electrode formed on the substrate; and a gas-sensing layer formed on the electrode, wherein the gas-sensing layer is a self-heating nanocolumnar structure having nanocolumns formed on the electrode and inclined with respect to the electrode with an angle of 60-89° and gas diffusion pores formed between the nanocolumns. The gas sensor according to the present disclosure requires no additional heater since it self-heats owing to the nanocolumnar structure and exhibits superior gas sensitivity even when no heat is applied from outside. Also, it can be mounted on mobile devices such as mobile phones because it consumes less power.

Claims

1. A gas sensor comprising:

a substrate;

an electrode formed on the substrate; and

a gas-sensing layer formed on the electrode,

wherein the gas-sensing layer is a self-heating nanocolumnar structure having nanocolumns formed on the electrode and inclined with respect to the electrode with an angle of 60-89° and

gas diffusion pores formed between the nanocolumns.

2. The gas sensor according to claim 1, wherein the nanocolumns are arranged on an x-y plane on the electrode such that the gas diffusion pores are formed between the nanocolumns arranged in one of the x and y directions and the nanocolumns arranged in the other direction are connected with each other.

3. The gas sensor according to claim 1, wherein the nanocolumns are formed by glancing angle deposition and the gas diffusion pores are formed in the self-shadowed region between the nanocolumns.

4. The gas sensor according to claim 1, wherein the gas-sensing layer comprises a metal oxide having a band gap of at least 2.7 eV.

5. The gas sensor according to claim 1, wherein the gas-sensing layer comprises at least one metal oxide selected from tungsten oxide (WO₃), tin oxide (SnO₂), niobium oxide (Nb₂O₅), zinc oxide (ZnO), indium oxide (In₂O₃), iron oxide (Fe₂O₃), titanium oxide (TiO₂), cobalt oxide (Co₂O₃) and gallium oxide (Ga₂O₃).

6. The gas sensor according to claim 1, wherein the substrate is a glass, sapphire, quartz or MgO substrate.

7. The gas sensor according to claim 1, wherein the electrode is a metal film, a metal oxide film or a carbon film.

8. The gas sensor according to claim 7, wherein the electrode is a metal film and the metal film comprises at least one selected from copper (Cu), gold (Au), silver (Ag) and platinum (Pt).

9. The gas sensor according to claim 7, wherein the electrode is a metal oxide film and the metal oxide film is an oxide film comprising at least one metal selected from indium (In), tin (Sn), zinc (Zn), aluminum (AD, niobium (Nb), titanium (Ti) and gallium (Ga).

10. The gas sensor according to claim 7, wherein the electrode is a metal oxide film and the metal oxide film is an oxide film selected from indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTC)), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO) and niobium-doped titanium oxide (NTO).

11. The gas sensor according to claim 7, wherein the electrode is a carbon film and the carbon film comprises graphene.

12. The gas sensor according to claim 1, wherein the electrode is a metal oxide film or a carbon film and the gas sensor has a light transmittance of at least 90% in the visible region.