Method for preparing graphene / copper composite material through solid-state carbon source assisted codeposition growth

Abstract

The invention relates to a method for preparing a graphene / copper composite material by using solid carbon source assisted codeposition growth, which comprises the following steps: pre-cleaning and heating a substrate in a thermal evaporation system, thermally depositing metal copper on the surface of the substrate, and thermally depositing carbon atoms on the surface of the substrate by using a solid carbon source, and graphene is grown on the surface of the metal copper in the process of depositing the metal copper. According to the method, copper and carbon atoms are synchronously deposited, graphene directly grows on the surfaces of copper particles, the content of graphene in the copper-based material can be increased, and then the conductivity of the copper-based material is improved.

Description

Technical Field

[0001] The invention belongs to the field of high-conductivity materials, and in particular relates to a method for preparing a graphene / copper composite material by utilizing a solid carbon source to assist codeposition growth. Background Art

[0002] Copper, with its high electrical and thermal conductivity, is currently the most important conductive material in power systems. However, current purification and single-crystallization technologies have reached the physical limits of copper, making it difficult to further reduce electrical losses caused by heat generation.

[0003] Graphene, a new two-dimensional planar material, possesses excellent mechanical properties and ultra-high carrier mobility. Embedding graphene as a reinforcing phase into metallic copper to form a graphene / copper composite material can significantly improve copper's overall electrical conductivity, mechanical properties, and other comprehensive properties.

[0004] In recent years, there have been many studies on graphene / copper composite materials both at home and abroad. The main method is to use chemical vapor deposition to grow graphene in situ on the surface of metal copper foil and then hot-press the graphene / copper to obtain a graphene / copper composite material with higher conductivity. However, this method is limited by the thickness of the copper foil and it is difficult to further increase the graphene content. It also limits the space for further regulation of the conductive properties of the graphene / copper material. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a graphene / copper composite material by using a solid carbon source to assist co-deposition growth, so as to increase the content of graphene in the copper-based composite material and thereby improve the electrical conductivity of the copper alloy material.

[0006] The present invention provides a method for preparing a graphene / copper composite material by utilizing a solid carbon source to assist co-deposition growth. The method comprises: placing a substrate in a thermal evaporation device for pre-cleaning and heat treatment, then thermally depositing metallic copper on the surface of the substrate, and simultaneously utilizing a solid carbon source to thermally deposit carbon atoms on the surface of the substrate, so that graphene is grown on the surface during the deposition of the metallic copper.

[0007] Preferably, the substrate material includes but is not limited to silicon or sapphire.

[0008] Preferably, the heating temperature of the substrate is 800-1050°C.

[0009] Preferably, the working gas pressure of the thermal deposition is 10-100 Pa.

[0010] Preferably, the power of the thermal deposition is 100-200W.

[0011] Preferably, the thermal deposition time is 5 to 120 minutes.

[0012] Preferably, the thermal deposition is performed under vacuum conditions.

[0013] Preferably, the thermal deposition temperature of the metallic copper is 1050-2500°C.

[0014] More preferably, the thermal deposition temperature of the metallic copper is 1100-2000°C.

[0015] Furthermore, the thermal deposition temperature of the metallic copper is 1500-1800°C.

[0016] Preferably, the solid carbon source includes but is not limited to any one of high-purity carbon rope or high-purity artificial graphite paper.

[0017] Preferably, the thermal deposition temperature of the solid carbon source is 3500-4000° C. Preferably, the thickness of the graphene is 1-10 nm.

[0018] Beneficial effects

[0019] (1) In the method of the present invention, copper and carbon atoms are deposited simultaneously, so that graphene grows directly on the surface of copper particles. Compared with the traditional method of growing a layer of atomic layer thick graphene on the surface of a very thick copper foil, which results in a very low graphene content, the method of the present invention uses a solid carbon source to assist the co-deposition growth to prepare a graphene / copper composite material, which can significantly increase the graphene content in the copper-based material.

[0020] (2) In the present invention, in-situ grown graphene is used to form chemical bonds with copper particles, thereby reducing interface resistance and thereby improving conductivity.

[0021] (3) The present invention adopts a single-step co-deposition process, which is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a macroscopic image of the graphene / copper composite material prepared in Example 1 of the present invention.

[0023] Figure 2 This is an optical microscope image of the graphene / copper composite material prepared in Example 1 of the present invention.

[0024] Figure 3 This is a Raman spectrum of the graphene / copper composite material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0026] Example 1

[0027] In this embodiment, the method for preparing a graphene / copper composite material using solid-state carbon source-assisted co-deposition growth is as follows: a substrate is pre-cleaned and heated to 1050°C in a thermal evaporation apparatus, a metallic copper source is heated to 1500°C, and a copper film is thermally deposited on the substrate. The thermal deposition power of the carbon rope is 200W, and the gas pressure is 10Pa. Copper and carbon atoms are simultaneously deposited on the substrate surface to obtain a graphene / copper composite material with a thickness of 800nm. The conductivity of the material is measured to be 116% IACS.

[0028] Figure 1 This is a macroscopic image of the graphene / copper composite material prepared in Example 1 of the present invention. It can be seen from the figure that the surface of the sample is smooth. Figure 2 Its optical microscope image shows that the surface is smooth and flat with a small amount of strip-shaped grain boundaries. Figure 3 The Raman spectrum shows the characteristic peaks of graphene, indicating that graphene exists inside the material.

[0029] Example 2

[0030] In this example, the method for preparing a graphene / copper composite using solid-state carbon source-assisted co-deposition growth is as follows: a substrate is pre-cleaned and heated to 1050°C in a thermal evaporation apparatus. A metallic copper source is heated to 1500°C and a copper film is thermally deposited onto the substrate. The carbon rope is thermally deposited at a power of 100W and a pressure of 10Pa, simultaneously depositing copper and carbon atoms onto the substrate surface to form a graphene / copper composite with a thickness of 800nm. The measured electrical conductivity of the material is 111% IACS. Compared to Example 1, the thermal deposition power is reduced to 100W.

[0031] Example 3

[0032] In this example, the method for preparing a graphene / copper composite using solid-state carbon source-assisted co-deposition growth is as follows: a substrate is pre-cleaned and heated to 1050°C in a thermal evaporation apparatus. A copper source is heated to 1500°C and a copper film is thermally deposited onto the substrate. The carbon rope is thermally deposited at a power of 200W and a pressure of 100 Pa, simultaneously depositing copper and carbon atoms onto the substrate surface to form a graphene / copper composite with a thickness of 800 nm. The measured electrical conductivity of the material is 106% IACS. Compared to Example 1, the pressure was changed to 100 Pa. The electrical conductivity of the graphene / copper composites prepared in Examples 1-3 was determined using a four-probe method and a step profiler. The results are shown in Table 1. Increasing the thermal deposition temperature improves the copper crystallization quality and creates a tighter interface between graphene and metal. Increasing the heating power of the carbon rope enhances the activity of the carbon atoms and also changes the graphene content, thereby affecting the electrical conductivity of the graphene / copper composite. The electrical conductivity of the graphene / copper composite material prepared by the present invention through the co-deposition growth assisted by a solid carbon source can reach above 105% IACS.

[0033] Table 1 Electrical conductivity of graphene / copper composite materials in Examples 1 to 3

[0034] Example 1 2 3 Conductivity (%IACS) 116 111 106

Claims

1. A method for preparing a graphene / copper composite material using solid carbon source-assisted co-deposition growth, the method comprising: The substrate is placed in a thermal evaporation system for pre-cleaning and heat treatment, and then metallic copper is thermally deposited on the substrate surface. Carbon atoms are also thermally deposited on the substrate surface using a solid carbon source, so that graphene grows on its surface simultaneously during the deposition of metallic copper.

2. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The substrate material includes either silicon or sapphire.

3. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The heating temperature of the substrate is 800-1050°C.

4. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The working gas pressure of the thermal deposition is 10-100 Pa.

5. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The power of the thermal deposition is 100-200W.

6. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The thermal deposition time is 5 to 120 minutes.

7. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The thermal deposition temperature of the metallic copper is 1050-2500°C.

8. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The solid carbon source includes any one of high-purity carbon rope and high-purity artificial graphite paper.

9. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The thermal deposition temperature of the solid carbon source is 3500-4000°C.

10. The method for preparing a graphene / copper composite material by utilizing solid carbon source-assisted co-deposition growth according to claim 1, characterized in that: The thickness of the graphene is 1-10 nm.

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