Transmission electron microscope micro-grid and method for making the same

Patent metadata

Field	Value
Publication number	US-10777378-B2
Application number	US-201916252702-A
Country	US
Kind code	B2
Filing date	Jan 20, 2019
Priority date	Jan 27, 2018
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

The present invention relates to a transmission electron microscope (TEM) micro-grid and a method for preparing the TEM micro-grid. The TEM micro-grid comprises a porous silicon nitride substrate and a graphene layer located on a surface of the porous silicon nitride substrate. The porous silicon nitride substrate comprises a plurality of through holes. The graphene layer covers the plurality of through holes. The method for preparing the TEM micro-grid provided in the present disclosure uses a carbon nanotube film structure to transfer a graphene layer to a surface of a porous silicon nitride substrate.

First claim

What is claimed is:

1. A transmission electron microscope (TEM) micro-grid comprising:
a porous silicon nitride substrate comprising a plurality of through holes;
a graphene layer on a surface of the porous silicon nitride substrate and covering the plurality of through holes.

2. The TEM micro-grid of claim 1 , wherein a thickness of the porous silicon nitride substrate ranges from 50 nanometers to 100 nanometers.

3. The TEM micro-grid of claim 1 , wherein diameters of the plurality of through holes range from 0.1 micrometers to 100 micrometers.

4. The TEM micro-grid of claim 1 , wherein the graphene layer is a continuous integrated structure.

5. The TEM micro-grid of claim 1 , wherein the graphene layer comprises one to three layers of graphene.

6. The TEM micro-grid of claim 1 , wherein the TEM micro-grid further comprises a supporting substrate, and the porous silicon nitride substrate is on a surface of the supporting substrate.

7. The TEM micro-grid of claim 6 , wherein the supporting substrate comprises a window.

8. The TEM micro-grid of claim 7 , wherein the plurality of through holes of the porous silicon nitride substrate is placed above the window of the silicon substrate.

9. The TEM micro-grid of claim 7 , wherein a size of the window ranges from 20 micrometers to 100 micrometers.

10. A method for preparing a TEM micro-grid comprising:
(S 1 ) providing a first substrate with a graphene layer on a surface of the first substrate;
(S 2 ) covering the graphene layer with a carbon nanotube film structure;
(S 3 ) obtaining a composite structure comprising the graphene layer and the carbon nanotube film by removing the first substrate with a corrosion solution to;
(S 4 ) cleaning the composite structure by placing the composite structure on a surface of a cleaning solution;
(S 5 ) providing a porous silicon nitride substrate comprising at least one through hole, and picking up the composite structure from the cleaning solution with the porous silicon nitride substrate by contacting the porous silicon nitride substrate with the graphene layer of the composite structure and covering the at least one through hole with the graphene layer;
(S 6 ) removing the carbon nanotube film structure from the composite structure.

11. The method of claim 10 , wherein the carbon nanotube film structure is a free-standing structure, and the carbon nanotube film structure consists of at least two carbon nanotube films stacked with each other.

12. The method of claim 11 , wherein each of the the carbon nanotube films comprises a plurality of carbon nanotubes joined end-to-end by van der Waals force therebetween and extending approximately along a same extending direction.

13. The method of claim 12 , wherein an angle between the extending directions of the carbon nanotubes in different carbon nanotube films ranges from 0 degrees to 90 degrees.

14. The method of claim 10 , wherein the step (S 5 ) comprises: inserting the porous silicon nitride substrate into the cleaning solution; and lifting the porous silicon nitride substrate to pick up the composite structure.

15. The method of claim 10 , wherein the step (S 6 ) comprises:
placing a polymer film on a surface of the carbon nanotube film structure away from the porous silicon nitride substrate;
treating the polymer film by heating or by irradiation to increase a crosslinking degree of the polymer film; and
tearing off the polymer film from the graphene layer.

16. The method of claim 15 , wherein a material of the polymer film is a thermosetting material.

17. The method of claim 15 , wherein the carbon nanotube film structure is covered by the polymer film.

18. The method of claim 10 , wherein the carbon nanotube film structure consists of n-layer carbon nanotube films stacked with each other, wherein n is an integer greater than or equals to two.

19. The method of claim 18 , wherein the step (S 6 ) comprises:
tearing off a first layer carbon nanotube film to an n−1th layer carbon nanotube film of the carbon nanotube film structure sequentially along an extending direction of the carbon nanotubes of the carbon nanotube film, wherein the first layer carbon nanotube film is farthest away from the graphene layer;
placing at least one strip on a surface of an nth layer carbon nanotube film away from the graphene layer, wherein the strip is placed at one side of the nth layer carbon nanotube film, the strip does not cover the graphene layer, and an extending direction of the strip is substantially perpendicular to the extending direction of the carbon nanotubes of the nth layer carbon nanotube film; and
tearing off the nth layer nanotube film from the graphene layer as the strip is being torn off along the extending directions of carbon nanotubes of the nth layer carbon nanotube film.

20. The method of claim 19 , wherein the strip is a polymer film or an adhesive tape.

Assignees

• Univ Tsinghua
• Hon Hai Prec Ind Co Ltd

Inventors

• Cong Lin
• Zhao Wei
• Zhang Jin
• Tsai Yu-Chien
• Jiang Kai-Li
• Fan Shou-Shan

Classifications

• H01J37/20 Primary

  Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support · CPC title

• H01J9/00

  Apparatus or processes specially adapted for the manufacture {, installation, removal, maintenance} of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps · CPC title

• H01J37/22

  Optical {, image processing} or photographic arrangements associated with the tube · CPC title

• H01J37/285

  Emission microscopes, e.g. field-emission microscopes · CPC title

• H01J37/26

  Electron or ion microscopes; Electron or ion diffraction tubes · CPC title