Method for producing metal-based particle assembly

Patent metadata

Field	Value
Publication number	US-9714461-B2
Application number	US-201314428521-A
Country	US
Kind code	B2
Filing date	Sep 2, 2013
Priority date	Sep 19, 2012
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

There is provided a method for producing a metal-based particle assembly, comprising the steps of: producing a metal-based film having an average thickness equal to or smaller than 50 nm on a substrate (a first step); and morphologically changing the metal-based film through a heat treatment into a metal-based particle assembly comprising a plurality of metal-based particles mutually separated and disposed in two dimensions (a second step). The method allows a metal-based particle assembly to be produced that for example includes 30 or more metal-based particles having an average particle diameter in a range of from 200 to 1600 nm, an average height in a range of from 55 to 500 nm, and an aspect ratio, as defined by a ratio of the average particle diameter to the average height, in a range of from 1 to 8.

First claim

The invention claimed is:

1. A method for producing a metal-based particle assembly, comprising:
a first step of producing a metal-based film having an average thickness equal to or smaller than 50 nm on a substrate; and
a second step of morphologically changing said metal-based film through a heat treatment into a metal-based particle assembly comprising a plurality of metal-based particles mutually separated and disposed in two dimensions, the second step being performed in an oxidizing atmosphere.

2. The method for producing a metal-based particle assembly according to claim 1 , wherein said heat treatment is performed at a temperature equal to or higher than 280° C.

3. The method for producing a metal-based particle assembly according to claim 1 , wherein said first step includes the step of applying a coating liquid on said substrate, said coating liquid containing particles made of a metal-based material that constitutes said metal-based film.

4. The method of producing a metal-based particle assembly according to claim 3 , wherein said coating liquid contains said particles at a concentration of 0.1-7% by weight.

5. The method for producing a metal-based particle assembly according to claim 1 , wherein said first step includes the step of producing said metal-based film on said substrate through vapor deposition.

6. The method for producing a metal-based particle assembly according to claim 1 , wherein a series of steps including said first step followed by said second step is repeated at least twice.

7. The method for producing a metal-based particle assembly according to claim 1 , wherein:
said metal-based particle assembly includes 30 or more said metal-based particles; and
said metal-based particles have an average particle diameter in a range of from 200 to 1600 nm, an average height in a range of from 55 to 500 nm, and an aspect ratio, as defined by a ratio of said average particle diameter to said average height, in a range of from 1 to 8, and said metal-based particles are disposed such that immediately adjacent ones thereof have an average distance therebetween in a range of from 1 to 150 nm.

8. The method for producing a metal-based particle assembly according to claim 1 , wherein:
said metal-based particle assembly includes 30 or more said metal-based particles;
said metal-based particles have an average particle diameter in a range of from 200 to 1600 nm, an average height in a range of from 55 to 500 nm, and an aspect ratio, as defined by a ratio of said average particle diameter to said average height, in a range of from 1 to 8; and
said metal-based particle assembly has in an absorption spectrum for a visible light region a maximum wavelength of a peak at a longest side in wavelength, and said maximum wavelength shifts toward a shorter side in wavelength in a range of from 30 to 500 nm as compared with that of a reference metal-based particle assembly in which metal-based particles having a particle diameter equal to said average particle diameter and a height equal to said average height and being identical in material to those of the former metal-based particle assembly are disposed such that each distance between adjacent metal-based particles may be in a range of from 1 to 2 μm.

9. The method for producing a metal-based particle assembly according to claim 1 , wherein:
said metal-based particle assembly includes 30 or more said metal-based particles;
said metal-based particles have an average particle diameter in a range of from 200 to 1600 nm, an average height in a range of from 55 to 500 nm, and an aspect ratio, as defined by a ratio of said average particle diameter to said average height, in a range of from 1 to 8; and
said metal-based particle assembly has in an absorption spectrum for a visible light region a maximum wavelength of a peak at a longest side in wavelength, and an absorbance at said maximum wavelength is higher as compared with that of a reference metal-based particle assembly in which metal-based particles having a particle diameter equal to said average particle diameter and a height equal to said average height and being identical in material to those of the former metal-based particle assembly are disposed such that each distance between adjacent metal-based particles may be in a range of from 1 to 2 μm, on the premise that the numbers of said metal-based particles are the same.

10. The method for producing a metal-based particle assembly according to claim 1 , wherein said metal-based particles are made of noble metal.

11. The method for producing a metal-based particle assembly according to claim 10 , wherein said metal-based particles are made of silver.

Assignees

• Sumitomo Chemical Co

Inventors

• Fukuura Tomohiro

Classifications

• H01L51/447

  Electricity · mapped topic

• B22F1/0018

  Operations & Transport · mapped topic

• C23C14/14

  Metallic material, boron or silicon · CPC title

• C23C14/5806 Primary

  Thermal treatment · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title