Stable aqueous dispersions of optically and electronically active phosphorene

Patent metadata

Field	Value
Publication number	US-10343909-B2
Application number	US-201715446832-A
Country	US
Kind code	B2
Filing date	Mar 1, 2017
Priority date	Mar 1, 2016
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

Methods for the preparation of few-layer phosphorene, compositions thereof and related devices fabricated therefrom.

First claim

We claim:

1. A method of preparing few-layer phosphorene, said method comprising:
providing a composition comprising a black phosphorus starting material, at least one amphiphilic surface active component and deoxygenated water;
sonicating said composition to provide a deoxygenated aqueous medium comprising exfoliated phosphorous nanomaterials; and
centrifuging said aqueous medium to provide a supernatant component comprising a polydisperse population of planar few-layer phosphorene nanomaterials comprising mono-, bi-, and n-layer few-layer phosphorene nanosheets, wherein n is an integer selected from 3- about 6,
wherein said surface active component is selected from alkali metal alkylsulfates and combinations thereof, or from non-ionic triblock oxyalkylene copolymers and combinations thereof.

2. The method of claim 1 wherein said surface active component is sodium dodecylsulfate.

3. The method of claim 1 wherein said surface active component is a copolymer of oxyethylene and oxypropylene.

4. The method of claim 1 comprising separating said few-layer phosphorene nanomaterials into two or more separation fractions comprising a subpopulation of few-layer phosphorene nanosheets comprising a surface area, each said fraction comprising monolayer phosphorene nanosheets, bilayer phosphorene nanosheets and trilayer phosphorene nanosheets, or combinations thereof.

5. The method of claim 4 wherein said separation comprises centrifuging said few-layer phosphorene nanomaterials in a deoxygenated fluid medium comprising a density gradient for at least one of a time and at a rotational rate sufficient to provide said separation fractions.

6. The method of claim 5 wherein said fluid medium comprises deoxygenated aqueous iodixanol.

7. The method of claim 6 wherein said fluid medium comprises a plurality of deoxygenated aqueous iodixanol concentrations, said density gradient comprising a range of concentration densities.

8. The method of claim 7 wherein a said few-layer phosphorene fraction is within said density gradient at a substantially invariant point during centrifugation, said invariant point comprising a density approximating the buoyant density of a said few-layer phosphorene fraction.

9. The method of claim 4 wherein at least one said separation fraction is isolated from said fluid medium and deposited on a substrate.

10. The method of claim 9 wherein said substrate and deposited few-layer phosphorene are incorporated into a device selected from electronic and optoelectronic devices.

11. A method of preparing few-layer phosphorene, said method comprising:
providing a composition comprising a black phosphorus starting material, at least one amphiphilic surface active component and deoxygenated water;
sonicating said composition to provide a deoxygenated aqueous medium comprising exfoliated phosphorous nanomaterials;
centrifuging said aqueous medium to provide a supernatant component comprising a polydisperse population of planar few-layer phosphorene nanomaterials comprising mono-, bi-, and n-layer few-layer phosphorene nanosheets, wherein n is an integer selected from 3- about 6; and
separating said few-layer nanomaterials into two or more separation fractions comprising a subpopulation of few-layer phosphorene nanosheets comprising a surface area, each said fraction comprising monolayer phosphorene nanosheets, bilayer phosphorene nanosheets and trilayer phosphorene nanosheets, or combinations thereof, said separation comprising centrifuging said few-layer phosphorene nanomaterials in a deoxygenated fluid medium comprising a density gradient for at least one of a time and at a rotational rate sufficient to provide said separation fractions, wherein said fluid medium comprises deoxygenated aqueous iodixanol.

12. The method of claim 11 wherein said surface active component is selected from alkali metal alkylsulfates and combinations thereof.

13. The method of claim 11 wherein said surface active component is selected from bile salts and combinations thereof.

14. The method of claim 11 wherein said surface active component is selected from non-ionic triblock oxyalkylene copolymers and combinations thereof.

15. The method of claim 11 wherein said fluid medium comprises a plurality of deoxygenated aqueous iodixanol concentrations, said density gradient comprising a range of concentration densities.

16. The method of claim 11 wherein at least one said separation fraction is isolated from said fluid mediums deposited on a substrate and incorporated into a device selected from electronic and optoelectronic devices.

Assignees

• Univ Northwestern

Inventors

• Hersam Mark C
• Kang Joohoon
• Wood Joshua D

Classifications

• H01L29/0665

  Electricity · mapped topic

• C01B25/003

  Phosphorus · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C01P2006/40

  Electric properties · CPC title

• H01L29/24

  Electricity · mapped topic