A method for repairing lattice defects of a multilayer graphene film

Abstract

The application discloses a kind of lattice defect repair methods of multilayer graphene film, comprising the following steps: S1, multilayer graphene grown with CVD method is placed into tube furnace, argon hydrogen mixture gas is passed in, gas pressure is kept 1-10Torr, and temperature is raised to 300-600 DEG C;S2, plasma source is opened, power 50-200W is kept for 1-10 minutes;S3, plasma source is closed, temperature is raised to 800-1000 DEG C under the same atmosphere and pressure;S4, carbon source gas is passed in, and temperature is kept for 30-300 minutes;S5, carbon source gas is closed, and temperature is reduced to room temperature under argon hydrogen mixture gas atmosphere, and sample is taken out;S6, sample is placed into graphite resistance radiation heating furnace;S7, argon hydrogen mixture gas is passed in in furnace, and gas pressure is kept 1-10Torr;S8, after furnace temperature is raised to 2500-3000 DEG C, temperature is kept for 60-300 minutes;S9, in argon hydrogen mixture gas, keep original gas pressure, slowly cool to room temperature, and sample is taken out.

Description

Technical Field

[0001] This invention belongs to the field of advanced materials technology and relates to a method for repairing lattice defects in multilayer graphene films. It effectively reduces vacancies, doping, grain boundaries, etc. in CVD-grown multilayer graphene, thereby achieving the effect of repairing lattice defects in graphene. Background Technology

[0002] Graphene is composed of sp 2 Graphene, a two-dimensional inorganic crystalline material composed of hybrid carbon atoms in a hexagonal honeycomb structure, consists of only one carbon atom layer with a thickness of just 0.335 nm. The discovery of graphene has caused a huge stir in the scientific community, and its emergence is expected to trigger a new revolution in the field of new materials. CVD (Chemical Vapor Deposition) is a convenient and effective method for large-scale preparation of graphene. In some applications, such as heat dissipation, it is necessary to grow multi-layered or even thicker graphene. However, the growth of thicker graphene leads to the generation of various lattice defects, such as vacancies, doping, and grain boundaries. These defects directly reduce phonon transport, thereby reducing the thermal conductivity of thicker graphene and failing to achieve effective heat dissipation.

[0003] The method provided by this invention patent can overcome the above difficulties, thereby repairing the lattice defects of multilayer graphene films. The method is simple and easy to implement, has a high yield, and is suitable for large-scale production. Summary of the Invention

[0004] This invention provides a method for repairing lattice defects in multilayer graphene films. This method is simple, easy to implement, highly repeatable, and suitable for large-scale production.

[0005] The technical solution provided by this invention is as follows: A method for repairing lattice defects in multilayer graphene films includes the following steps: S1. Place the multilayer graphene grown by CVD into a tube furnace, introduce an argon-hydrogen mixture, maintain the pressure at 1-10 Torr, and raise the temperature to 300-600℃. S2. Turn on the plasma source, power 50-200W, and maintain for 1-10 minutes; S3. Turn off the plasma source and heat to 800-1000℃ under the same atmosphere and pressure; S4. Introduce carbon source gas and maintain the temperature for 30-300 minutes; S5. Turn off the carbon source gas, maintain the gas pressure at 1-10 Torr in an argon-hydrogen mixed atmosphere, cool down to room temperature, and remove the sample; S6. Place the sample into a graphite resistance radiation heating furnace; S7. Argon-hydrogen mixture is introduced into the furnace, and the pressure is maintained at 1-10 Torr. S8. After raising the furnace temperature to 2500-3000℃, keep it at that temperature for 60-300 minutes. S9. In an argon-hydrogen mixture, maintain the original pressure and slowly cool down to room temperature before removing the sample.

[0006] Preferably, in step S1, the volume percentage of hydrogen in the argon-hydrogen mixture is 5%-10%.

[0007] Preferably, in step S2, the temperature should not be too high and the time should not be too long.

[0008] Preferably, the heating and cooling rate is controlled to be from 1 ℃ / min to 5 ℃ / min.

[0009] Preferably, the carbon source gas is any one or a combination of carbon monoxide, methane, acetylene, ethanol, benzene, toluene, cyclohexane, and phthalocyanine.

[0010] Preferably, in step S8, the higher the annealing temperature, the shorter the annealing time.

[0011] The present invention can bring the following beneficial effects: 1) This invention can repair lattice defects in multilayer graphene films to the greatest extent.

[0012] 2) The preparation method of this invention has high repeatability, is simple and easy to implement, and is suitable for industrial production. Attached Figure Description

[0013] Figure 1 This is the Raman spectrum of the multilayer graphene film repaired in the example. Detailed Implementation

[0014] To facilitate understanding of this application and to make the aforementioned objectives, features, and advantages of this application more apparent, a detailed description of specific embodiments of this application is provided below in conjunction with the accompanying drawings. Numerous specific details are set forth in the following description to provide a thorough understanding of this application, and preferred embodiments are shown in the accompanying drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application. This application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0015] To keep the drawings simple, each drawing only schematically shows the parts related to the present invention, and they do not represent the actual structure of the product.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0017] A method for repairing lattice defects in multilayer graphene films includes the following steps: S1. Place the multilayer graphene grown by CVD into a tube furnace, introduce an argon-hydrogen mixture, maintain the pressure at 1-10 Torr, and raise the temperature to 300-600℃. S2. Turn on the plasma source, power 50-200W, and maintain for 1-10 minutes; S3. Turn off the plasma source and heat to 800-1000℃ under the same atmosphere and pressure; S4. Introduce carbon source gas and maintain the temperature for 30-300 minutes; S5. Turn off the carbon source gas, maintain the gas pressure at 1-10 Torr in an argon-hydrogen mixed atmosphere, cool down to room temperature, and remove the sample; S6. Place the sample into a graphite resistance radiation heating furnace; S7. Argon-hydrogen mixture is introduced into the furnace, and the pressure is maintained at 1-10 Torr. S8. After raising the furnace temperature to 2500-3000℃, keep it at that temperature for 60-300 minutes. S9. In an argon-hydrogen mixture, maintain the original pressure and slowly cool down to room temperature before removing the sample.

[0018] Specific experiments were conducted based on the above experimental steps, resulting in the following examples: Example

[0019] A method for repairing lattice defects in multilayer graphene films includes the following steps: S1. Place the multilayer graphene grown by CVD into a tube furnace, introduce 500 sccm of argon and 50 sccm of hydrogen, maintain the gas pressure at 5 Torr, and raise the temperature to 350℃. S2. Turn on the plasma source, power 100W, and maintain for 5 minutes; S3. Turn off the plasma source and heat to 900℃ under the same atmosphere and pressure; S4. Introduce ethylene and keep warm for 60 minutes; S5. Stop the ethylene supply, continue to supply 500 sccm of argon and 50 sccm of hydrogen, maintain the gas pressure at 5 Torr, cool to room temperature at 5℃ / min, and remove the sample. S6. Place the sample into a graphite resistance radiation heating furnace; S7. Introduce 500 sccm of argon and 50 sccm of hydrogen into the furnace, maintaining a pressure of 1 Torr. S8. After raising the furnace temperature to 2800℃, keep it at that temperature for 60 minutes. S9. Continue to purge the furnace with 500 sccm of argon and 50 sccm of hydrogen, maintaining a pressure of 1 Torr. Cool the furnace to room temperature at a rate of 1 °C / min and remove the sample.

[0020] S10. Measure the sample using Raman spectroscopy (e.g.) Figure 1 (As shown).

[0021] The obtained multilayer graphene film is intact and without obvious defects.

[0022] It should be noted that the above description is only a preferred embodiment of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for repairing lattice defects in a multilayer graphene film, comprising the following steps: S1. Place the multilayer graphene grown by CVD into a tube furnace, introduce an argon-hydrogen mixture, maintain the pressure at 1-10 Torr, and raise the temperature to 300-600℃. S2. Turn on the plasma source, power 50-200W, and maintain for 1-10 minutes; S3. Turn off the plasma source and heat to 800-1000℃ under the same atmosphere and pressure; S4. Introduce carbon source gas and maintain the temperature for 30-300 minutes; S5. Turn off the carbon source gas, maintain the gas pressure at 1-10 Torr in an argon-hydrogen mixed atmosphere, cool down to room temperature, and remove the sample; S6. Place the sample into a graphite resistance radiation heating furnace; S7. Argon-hydrogen mixture is introduced into the furnace, and the pressure is maintained at 1-10 Torr. S8. After raising the furnace temperature to 2500-3000℃, keep it at that temperature for 60-300 minutes. S9. In an argon-hydrogen mixture, maintain the original pressure and slowly cool down to room temperature before removing the sample.

2. The method for repairing lattice defects in multilayer graphene films according to claim 1, characterized in that: Steps S1 and S2 use argon-hydrogen plasma to remove contaminants from the graphene surface.

3. The method for repairing lattice defects in multilayer graphene films according to claim 1, characterized in that: Steps S3-S5 use vapor deposition to fill the defect sites.

4. The method for repairing lattice defects in multilayer graphene films according to claim 1, characterized in that: Steps S6-S9, involving ultra-high temperature annealing in an argon-hydrogen mixed atmosphere, can repair lattice defects and selectively etch amorphous carbon.

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