Conductive nanowire films

Patent metadata

Field	Value
Publication number	US-10403414-B2
Application number	US-201615161969-A
Country	US
Kind code	B2
Filing date	May 23, 2016
Priority date	Mar 1, 2012
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

The invention provides a novel conductive film and a multilayered conductive structure, comprising a plurality of metal nanowires arranged in clusters and having an average aspect ratio of least 100,000, optionally decorated by metal nanoparticles. It is also disclosed a process for preparation of a conductive film comprising metal nanowires by surfactant/template assisted method which involves the use of a precursor solution based on surfactant (such as CTAB), metal precursor (such as HAuCl4 and AgNO3) and reducing agent (such as metal borohydride or sodium ascorbate).

First claim

The invention claimed is:

1. A process for the preparation of a conductive film, said process comprising:
(a) obtaining an aqueous precursor solution comprising at least one metal precursor, at least one surfactant and at least one metal reducing agent;
(b) forming a thin-film of the precursor solution on at least a portion of a surface of a substrate; and
(c) allowing formation of a first layer of metal nanowires;
wherein one or both of the steps (d) and (e) are carried out:
(d) forming a stacking of two or more metal nanowire layers by forming a further layer or layers on a surface of the first layer of metal nanowires, wherein the further layer or layers is formed in same manner as that of the formation of the first layer of metal nanowire; and
(e) treating the layer of metal nanowires or the stacking of metal nanowire layers with a solution comprising at least one surfactant, at least one metal precursor and at least one weak metal reducing agent;
to thereby obtain the conductive film of nanowires on at least a portion of said surface of the substrate,
the conductive film comprising
at least one conductive layer, comprising
an arrangement of electrically conductive metal nanowires, the nanowires having on average an aspect-ratio of at least 100,000, at least 70% of said nanowires being arranged in one or more clusters, wherein each cluster comprising two or more nanowires oriented parallel to each other along the same axis, wherein the inter-wire spacing within the cluster is below 20 nm.

2. The process according to claim 1 , wherein a protective layer is formed in step (e).

3. The process according to claim 1 , wherein said nanowires are coated in a film of at least one surfactant.

4. The process according to claim 1 , wherein the nanowires are branched and/or curved.

5. The process according to claim 1 , wherein the nanowires are arranged in an organic template formed by a surrounding surfactant material.

6. The process according to claim 1 , wherein said cluster comprises homogenously spaced nanowires.

7. The process according to claim 1 , wherein the inter-nanowire spacing is between 2 nm and 10 nm.

8. The process according to claim 1 , wherein said cluster comprises between 2 and 500 nanowires.

9. The process according to claim 1 , wherein step (d) is carried out one or more times and step (e) is not carried out.

10. The process according to claim 1 , wherein step (d) is not carried out and step (e) is carried out.

11. The process according to claim 1 , wherein said precursor solution comprises metal, semiconductor or metal oxide nanoparticles.

12. The process according to claim 1 , wherein the at least one metal reducing agent in step (a) triggers formation of metal seed particles in solution, and wherein step (e) is carried out.

Assignees

• Univ Ramot
• P V Nano Cell Ltd

Inventors

• Markovich Gil
• Azulai Daniel
• Levi-Belenkova Tatyana
• Gilon Hagit
• De La Vega Fernando
• Kabla Ayala

Classifications

• H10P14/46

  using a liquid · CPC title

• C23C18/44

  using reducing agents · CPC title

• C23C18/1651

  Two or more layers only obtained by electroless plating · CPC title

• G02F2202/36

  Micro- or nanomaterials · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title