Process for manufacturing silicon-based nanoparticles from metallurgical-grade silicon or refined metallurgical-grade silicon

Patent metadata

Field	Value
Publication number	US-9352969-B2
Application number	US-201214004018-A
Country	US
Kind code	B2
Filing date	Mar 9, 2012
Priority date	Mar 9, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A process for manufacturing silicon-based nanoparticles by electrochemical etching of a substrate, wherein the substrate is a metallurgical-grade or upgraded metallurgical-grade silicon, the substrate including an impurity content greater than 0.01%.

First claim

The invention claimed is:

1. A process for manufacturing hydrogen via silicon-based nanopowders, comprising:
providing a substrate made of metallurgical-grade silicon or upgraded metallurgical-grade silicon having an impurity content greater than 10 ppm by weight,
electrochemically etching said substrates to form silicon-based nanopowders having a hydrogen release energy lower than the hydrogen release energy of a silicon nanopowder obtained from electronic- or solar-grade silicon, and
producing hydrogen via the silicon-based nanopowders.

2. The process according to claim 1 , wherein the substrate comprises a boron content greater than or equal to 5 ppm by weight.

3. The process according to claim 1 , wherein the substrate comprises a boron content greater than 50 ppm by weight.

4. The process according to claim 1 , wherein the impurity content comprises an aluminum content, iron content, calcium content, phosphorus content, and boron content.

5. The process according to claim 4 , wherein the aluminum content, iron content, calcium content, phosphorus content, and boron content each range between 1 and 10,000 ppm by weight.

6. The process according to claim 1 , wherein the substrate further comprises copper, titanium, nickel, chromium, and tungsten.

7. The process according to claim 1 , wherein the substrate further comprises structural defects with a density greater than 10 4 defects/cm 2 .

8. The process according to claim 1 , wherein the electrochemical etching is performed by pulsed electric current.

9. The process according to claim 1 , wherein the electrochemical etching is performed by an electric current comprised between 1 mA/cm 2 and 1 A/cm 2 .

10. The process according to claim 9 , wherein the electrochemical etching is performed by an electric current comprised between 1 mA/cm 2 and 500 mA/cm 2 .

11. The process according to claim 10 , wherein the electrochemical etching is performed by an electric current comprised between 1 mA/cm 2 and 250 mA/cm 2 .

12. The process according to claim 1 , further comprising:
forming an aluminum layer on a backside of the substrate,
annealing the substrate comprising the aluminum layer for doping the substrate.

13. The process according to claim 12 , wherein a thickness of the aluminum layer ranges between 10 nm and 10 μm.

14. The process according to claim 12 , further comprising removing the aluminum layer after annealing the substrate.

15. The process according to claim 1 , further comprising:
illuminating a front side of the substrate opposite a backside of the substrate by means of a source of white light generating a luminous radiation for doping the substrate.

Assignees

• Lysenko Volodymyr
• Kraiem Jed
• Medjaoui Mahdi
• Inst Nat Sciences Appliq
• Centre Nat Rech Scient
• Apollon Solar

Inventors

• Lysenko Volodymyr
• Kraiem Jed
• Medjaoui Mahdi

Classifications

• C01B33/021 Primary

  Preparation (chemical coating from the vapour phase C23C16/00) · CPC title

• C25F3/12

  of semiconducting materials · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01B3/10

  by reaction of water vapour with metals · CPC title

• B82Y30/00

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