A method of transferring a thick graphene film grown by CVD
By dry-transferring thick graphene films to target substrates, the problem of non-recyclable nickel foil has been solved, production costs have been reduced, environmental pollution has been decreased, and the reuse of nickel foil has been realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XI XI TECH (SHANGHAI) CO LTD
- Filing Date
- 2024-12-16
- Publication Date
- 2026-06-23
AI Technical Summary
In existing technologies, the strong bonds between nickel foil and graphene prevent effective dry transfer, resulting in the inability to recycle the nickel foil, increasing production costs and polluting the environment.
A dry transfer method was adopted, in which nickel foil was treated at low temperature and at high temperature, and graphene film was gradually transferred by using PDMS pressing and tweezers, so that nickel foil could be reused.
The dry transfer of thick graphene films to target substrates was achieved, reducing production costs and environmental pollution, and improving the reusability of nickel foil.
Smart Images
Figure CN122254497A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of advanced materials technology and relates to a method for transferring a thick graphene film grown by CVD. This method can effectively transfer a thick graphene film grown on a nickel foil to a target substrate, and the nickel foil can be reused. 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, has only one carbon atom layer and 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 is a convenient and effective method for large-scale preparation of graphene, but it can generally only grow high-quality graphene on metal substrates. In some applications, such as heat dissipation, it is necessary to grow multi-layered or even thicker graphene. Currently, the effective substrate for growing thick graphene is nickel foil, but the bonding between nickel foil and graphene is quite strong, making it impossible to transfer graphene from the nickel foil using dry transfer methods. Therefore, the current conventional method is still wet transfer, using chemical reagents to etch away the nickel foil. This method makes it impossible to recycle the nickel foil, resulting in a significant increase in production costs and hindering end-use applications; at the same time, the production process also generates a large amount of chemical waste liquid, impacting environmental pollution.
[0003] The method provided by this invention patent can overcome the above difficulties, enabling the thick graphene film grown on nickel foil to be transferred to the target substrate by dry method, allowing the nickel foil to be recycled, reducing costs and pollution. Summary of the Invention
[0004] This invention provides a method for transferring thick graphene films grown by CVD. This method is simple, easy to implement, highly repeatable, and allows for the reuse of nickel foil, thereby reducing the production cost of graphene.
[0005] The technical solution provided by this invention is as follows: A method for transferring a CVD-grown thick graphene film includes the following steps: S1. Thick graphene is grown on nickel foil using CVD. S2. After removing the nickel foil with graphene, place it in a freezer at -40℃ and let it stand for a period of time. S3. Remove the graphene-coated nickel foil from the freezer and place it in a 300°C oven for a period of time. S4. Repeat steps S2 and S3 several times; S5. Press PDMS onto the nickel foil with graphene, apply a certain force, and slowly peel off the PDMS. The graphene will also be peeled off along with the PDMS. S6. Use tweezers to slowly remove the thick graphene film from the PDMS.
[0006] Preferably, in step S1, before growing graphene, the nickel foil is annealed at a temperature of 300℃ to 1000℃ for a time of 10-120 min, and the annealing is carried out in an argon-hydrogen mixture.
[0007] Preferably, the heating and cooling rate is controlled to be from 0.1 ℃ / s to 100 ℃ / s.
[0008] Preferably, the carbon-containing gas is any one or a combination of carbon monoxide, methane, acetylene, ethanol, benzene, toluene, cyclohexane, and phthalocyanine.
[0009] Preferably, in step S2, the freezing time can be from 30 minutes to 24 hours.
[0010] Preferably, in step S3, the heat preservation time in the oven can be from 30 minutes to 24 hours.
[0011] Preferably, in step S4, the pressure of the PDMS film pressed onto the graphene is between 1 and 100 Pa.
[0012] Preferably, in step S4, the slower the rate at which the graphene is peeled off, the better.
[0013] The present invention can bring the following beneficial effects: 1) This invention can successfully dry transfer a thick graphene film grown on a nickel foil to a target substrate.
[0014] 2) The preparation method of the present invention has high repeatability, is simple and easy to implement, and allows the nickel foil to be reused repeatedly. Attached Figure Description
[0015] Figure 1 This is a picture of the thick graphene film that has been peeled off.
[0016] Figure 2 This is the Raman spectrum of the thick graphene film prepared in the example. Detailed Implementation
[0017] 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.
[0018] 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.
[0019] 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.
[0020] This invention relates to a method for transferring thick graphene films grown by CVD, comprising the following steps: S1. Thick graphene is grown on nickel foil using CVD. S2. After removing the nickel foil with graphene, place it in a freezer at -40℃ and let it stand for a period of time. S3. Remove the graphene-coated nickel foil from the freezer and place it in a 300°C oven for a period of time. S4. Repeat steps S2 and S3 several times; S5. Press PDMS onto the nickel foil with graphene, apply a certain force, and slowly peel off the PDMS. The graphene will also be peeled off along with the PDMS. S6. Use tweezers to slowly remove the thick graphene film from the PDMS.
[0021] Specific experiments were conducted based on the above experimental steps, resulting in the following examples: Example
[0022] S1. Place the nickel foil in the center of the CVD furnace; use a vacuum pump to remove the air from the heat-resistant tube and introduce a mixed gas of 800 SCCM Ar and 100 SCCM H2. After 30 minutes of gas introduction, start heating the furnace body to bring the temperature of the substrate holder 3 inside the furnace to 1000 ℃. Anneal at this temperature for 30 minutes.
[0023] S2. After annealing, 10 SCCM of methane is introduced into the heat-resistant tube as a carbon source gas, while maintaining the heat-resistant tube at atmospheric pressure of 1 atm to start the reaction. After the reaction proceeds for 30 minutes, the introduction of methane is stopped, and a mixture of 800 SCCM of Ar and 100 SCCM of MH2 is introduced. The temperature inside the furnace is slowly cooled (at a rate of about 1 °C / s) to room temperature, and the nickel foil with the thick graphene film is removed.
[0024] S3. Place the nickel foil with the thick graphene film in a freezer at -40°C for 2 hours.
[0025] S4. Remove the nickel foil with the thick graphene film from the freezer and place it in a 300°C oven for 2 hours.
[0026] S5. Repeat steps S3 and S4 5 times each.
[0027] S6. Remove the sample, press it onto the graphene with PDMS, apply a pressure of 5 Pa, and maintain for 30 minutes.
[0028] S7. Slowly peel the graphene and PDMS completely off the nickel foil.
[0029] S8. Use tweezers to slowly remove the thick graphene film from the PDMS. Figure 1 The image shows the subsequent thick graphene film. (As shown...) Figure 2 The image shows the Raman spectrum of the obtained sample.
[0030] The resulting graphene film is intact and free of obvious defects, and the nickel foil can be reused.
[0031] 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 transferring a CVD-grown thick graphene film, comprising the following steps: S1. Thick graphene is grown on nickel foil using CVD. S2. After removing the nickel foil with graphene, place it in a freezer at -40℃ and let it stand for a period of time. S3. Remove the graphene-coated nickel foil from the freezer and place it in a 300°C oven for a period of time. S4. Repeat steps S2 and S3 several times; S5. Press PDMS onto the nickel foil with graphene, apply a certain force, and slowly peel off the PDMS. The graphene will also be peeled off along with the PDMS. S6. Use tweezers to slowly remove the thick graphene film from the PDMS.
2. The method for transferring the CVD-grown thick graphene film according to claim 1, characterized in that: Nickel and graphene have significantly different coefficients of thermal expansion. Repeatedly changing between high and low temperatures can weaken or even destroy the strong bonds between graphene and nickel, making it easier to peel off the graphene using a dry method, thus allowing the nickel foil to be reused.