Graphene-copper multilayer composite material and preparation method thereof

Abstract

According to the graphene-copper multilayer composite material and the preparation method thereof, a graphene layer is deposited through a plasma enhanced chemical vapor deposition (PECVD) technology, then a copper layer is deposited through an electron beam deposition technology, and the process is repeated to form a multilayer structure. The volume fraction of the graphene is controlled between 0.007% and 0.010%, so that the conductivity is optimized. The conductivity of the graphene-copper multilayer composite material at the room temperature reaches 105.1% IACS, the conductivity of the graphene-copper multilayer composite material is 4.0-5.0% higher than that of a pure copper substrate, the graphene-copper multilayer composite material is suitable for the fields of high-performance electronic equipment, electric vehicle traction motors, wind driven generators and the like, and meanwhile a material basis is provided for developing novel electronic devices such as sensors and super capacitors.

Description

Technical Field

[0001] The invention relates to a graphene-copper multilayer composite material and a preparation method thereof, and in particular to a technology for improving the conductivity of the graphene-copper multilayer composite material. Background Art

[0002] Copper, as a widely used conductive material, is widely used in various electronic devices due to its good conductivity. However, with the development of technology, the performance requirements for conductive materials are getting higher and higher, and it is difficult to meet the needs of high-performance electronic devices by relying solely on pure copper. Therefore, researchers have been exploring ways to improve the conductivity of copper by combining it with other materials. Among them, graphene has become an ideal composite material due to its extraordinary carrier mobility and long average free path. Summary of the invention

[0003] The present invention provides a graphene-copper multilayer composite material and a preparation method thereof, which can significantly improve the electrical conductivity of the composite material. By alternately depositing graphene and copper layers on a copper substrate to form a multilayer structure, and by controlling the amount of graphene added, the electrical conductivity of copper at room temperature is significantly improved relative to the International Annealed Copper Standard (IACS).

[0004] The present invention provides a method for enhancing the conductivity of a graphene-copper multilayer composite material, and the specific steps are as follows: a. Deposition of graphene layer on copper substrate by plasma enhanced chemical vapor deposition (PECVD) technique; b. depositing a copper layer on the graphene layer by electron beam deposition technology; c. Repeat steps a and b to form a multilayer graphene-copper composite material; d. The volume fraction of graphene is 0.007-0.010%.

[0005] More detailed steps include: Material preparation: Select copper foil with a purity of 5N as the substrate, clean the copper substrate with acetone in an ultrasonic bath, and then blow dry with inert gas.

[0006] Graphene deposition: The cleaned copper substrate is placed in a CVD chamber, the pressure of the CVD chamber is evacuated, and the temperature is raised to 600-660°C. Graphene is synthesized using radio frequency plasma in a mixed flow of CH4 and H2, and the reaction time is about 10-15 minutes.

[0007] Copper layer deposition: Copper film was deposited on the graphene layer using an electron beam evaporator with a deposition rate set at 10-12 Å / s. The film thickness and deposition rate were monitored by a quartz crystal microbalance.

[0008] Repeating the deposition: Repeating the deposition process of the graphene and copper layers to form a multilayer composite material of at least six layers of copper and six layers of graphene with a total thickness of greater than 1.0 micrometer.

[0009] Testing: The electrical conductivity of the multilayer composite material was measured from room temperature to 200°C using the four-wire method. The conductivity of the sample at room temperature was 105.1% IACS.

[0010] Furthermore, the average thickness of the copper layer is defined to be about 200 nanometers.

[0011] Furthermore, the graphene layer is arranged in a plane and is equidistant from the copper layer.

[0012] The present invention also provides a reinforced graphene-copper multilayer composite material, wherein the composite material has a conductivity that is about 4.0-5.0% higher than that of the copper substrate.

[0013] The present invention also provides an enhanced graphene-copper multilayer composite material, which has a conductivity about 4.0-5.0% higher than that of a copper substrate, comprises no less than six layers of copper and six layers of graphene, and has a total thickness of 1.0-2.0 microns, but does not include the substrate.

[0014] The graphene-copper multilayer composite material of the present invention can be widely used in electronic devices that require high conductivity, such as electric vehicle traction motors, wind turbines, high-performance computer chips, conductive cables, etc. In addition, the composite material can also be used to develop new electronic devices, such as sensors, supercapacitors and electromagnetic shielding materials.

[0015] The present invention also provides a method for improving conductivity using a graphene-copper multilayer composite material, comprising: Apply graphene-copper multilayer composites to devices that require high electrical conductivity; The conductivity is improved by optimizing the alternating arrangement of graphene layers and copper layers, and controlling the volume fraction of graphene and the thickness of the copper layer. The volume fraction of graphene is controlled to be lower than 0.010%, and the average thickness of the copper layer is controlled to be lower than 230 nanometers. DETAILED DESCRIPTION

[0016] (1) Material preparation: Select copper foil with a purity of 5N as the substrate. Use acetone to clean the copper substrate in an ultrasonic bath and then blow dry with inert gas.

[0017] (2) Graphene deposition: The cleaned copper substrate is placed in a CVD chamber, the pressure in the CVD chamber is evacuated, and the temperature is raised to 600-660°C. Graphene is synthesized using radio frequency plasma in a mixed gas flow of CH4 and H2, and the reaction time is about 10-15 minutes.

[0018] (3) Copper layer deposition: A copper film was deposited on the graphene layer using an electron beam evaporator. The deposition rate was set to 10-12 Å / s, and the film thickness and deposition rate were monitored by a quartz crystal microbalance.

[0019] (4) Repeating the deposition process of the graphene and copper layers to form a multilayer composite material of at least six layers of copper and six layers of graphene with a total thickness of greater than 1.0 micrometer.

[0020] (5) Testing: The electrical conductivity of the multilayer composite material was measured from room temperature to 200°C using the four-wire method. The conductivity of the sample at room temperature was 105.1% IACS.

[0021] The graphene-copper multilayer composite material of the present invention forms a multilayer structure with excellent electrical conductivity by alternately depositing graphene and copper layers on a copper substrate. The addition of graphene not only improves the electrical conductivity of the composite material, but also maintains a high carrier mobility, so that the composite material has a wide range of application potentials in high-performance electronic devices. In addition, calculations by a parallel resistance model show that if the thickness of the copper layer can be further reduced, the electrical conductivity of the composite material can be further improved.

[0022] The addition of graphene not only improves the conductivity of the composite material, but also maintains high carrier mobility, providing an ideal conductive material for high-performance electronic devices.

[0023] The present invention provides a simple and effective method for preparing a graphene-copper multilayer composite material by plasma enhanced chemical vapor deposition (PECVD) and electron beam deposition technology, and the method can achieve precise control of the thickness and distribution of the graphene and copper layers.

[0024] During the preparation process, the materials and technologies used in the present invention meet environmental protection requirements, generate less waste, are easy to handle, are conducive to popularization and application, and reduce the impact on the environment.

Claims

1. A method for enhancing the conductivity of a graphene-copper multilayer composite material, comprising the following steps: a. Deposition of graphene layer on copper substrate by plasma enhanced chemical vapor deposition (PECVD) technique; b. depositing a copper layer on the graphene layer by electron beam deposition technology; c. Repeat steps a and b to form a multilayer graphene-copper composite material; d. The volume fraction of graphene is 0.007-0.010%.

2. The method according to claim 1, wherein the total thickness of the multilayer composite material formed by the alternating deposition of graphene layers and copper layers is greater than 1 micron.

3. The method of claim 1 or 2, wherein the average thickness of the copper layer is about 200 nanometers.

4. A method according to any preceding claim, wherein the graphene layer is arranged in a plane and equidistant from the copper layer.

5. A graphene-copper multilayer composite material, prepared by the method of claims 1-4, and having a conductivity about 4.0-5.0% higher than that of a copper substrate.

6. The graphene-copper multilayer composite material according to claim 7, wherein the composite material comprises no less than six layers of copper and six layers of graphene, with a total thickness of 1.0-2.0 microns, but excluding the substrate.

7. A method for improving conductivity using a graphene-copper multilayer composite material, comprising the following steps: a. Applying graphene-copper multilayer composites to highly conductive devices; b. Improvement of conductivity is achieved by optimizing the alternating arrangement of graphene layers and copper layers, and controlling the volume fraction of graphene and the thickness of the copper layer; c. Control the volume fraction of graphene to be lower than 0.010% and the average thickness of the copper layer to be lower than 230 nanometers.