阅读说明：本技术 铜镍合金及其制备方法和应用、二维材料生长衬底 (Copper-nickel alloy, preparation method and application thereof, and two-dimensional material growth substrate ) 是由 刘忠范 梁宇 李杨立志 孙禄钊 刘海洋 陈步航 于 2020-05-25 设计创作，主要内容包括：本发明提供一种铜镍合金及其制备方法和应用,以及二维材料生长衬底,该铜镍合金的制备方法包括：对铜箔进行预退火处理；预退火处理后的铜箔经镀镍处理得到铜镍复合箔；及铜镍复合箔经退火合金化处理,得到铜镍合金。本发明通过对铜箔进行预退火处理,可有效解决铜镍原子在退火合金化过程当中因应力释放导致的箔材卷曲、表面粗糙化的问题,得到表面平整度Ra＜150nm的铜镍合金。该铜镍合金可作为衬底生长二维材料,例如石墨烯,有效提高石墨烯质量,降低石墨烯转移破损率。本发明的制备方法工艺简单、成本低,对进一步实现和拓展石墨烯的高端应用具有重要的意义。(The invention provides a copper-nickel alloy, a preparation method and application thereof, and a two-dimensional material growth substrate, wherein the preparation method of the copper-nickel alloy comprises the following steps: carrying out pre-annealing treatment on the copper foil; carrying out nickel plating treatment on the copper foil subjected to the pre-annealing treatment to obtain a copper-nickel composite foil; and annealing and alloying the copper-nickel composite foil to obtain the copper-nickel alloy. The invention can effectively solve the problems of foil curling and surface roughening caused by stress release in the annealing alloying process of copper-nickel atoms by carrying out pre-annealing treatment on the copper foil, and obtains the copper-nickel alloy with the surface flatness Ra less than 150 nm. The copper-nickel alloy can be used as a substrate to grow a two-dimensional material, such as graphene, so that the quality of the graphene is effectively improved, and the transfer damage rate of the graphene is reduced. The preparation method disclosed by the invention is simple in process and low in cost, and has important significance in further realizing and expanding high-end application of graphene.)

1. A preparation method of a copper-nickel alloy is characterized by comprising the following steps:

carrying out pre-annealing treatment on the copper foil;

carrying out nickel plating treatment on the copper foil subjected to the pre-annealing treatment to obtain a copper-nickel composite foil; and

and annealing and alloying the copper-nickel composite foil to obtain the copper-nickel alloy.

2. The method of claim 1, wherein the copper foil is a polycrystalline copper foil or a single crystal copper foil, and the copper foil has a thickness of 10 to 100 μm.

3. The production method according to claim 2, wherein the copper foil is a high-index-surface single-crystal copper foil.

4. The preparation method according to claim 1, wherein the pre-annealing treatment is performed under an inert atmosphere, the temperature of the pre-annealing treatment is 800 ℃ to 1050 ℃, and the time of the pre-annealing treatment is not less than 30 minutes.

5. The preparation method according to claim 1, wherein the annealing alloying treatment is performed under an inert atmosphere, the temperature of the annealing alloying treatment is 1000 ℃ to 1100 ℃, and the time of the annealing alloying treatment is not less than 1 hour.

6. The method of claim 1, wherein the nickel plating treatment is performed by one or more methods selected from the group consisting of an electrochemical method, a magnetron sputtering method, a vapor deposition method, and a vacuum evaporation plating method.

7. The method according to claim 1, wherein the thickness of the nickel obtained after the nickel plating treatment is 0.5 to 20 μm.

8. A copper-nickel alloy prepared by the method of any one of claims 1 to 7.

9. Use of the copper-nickel alloy according to claim 8 as a two-dimensional material growth substrate.

10. A two-dimensional material growth substrate employing the copper-nickel alloy of claim 8.

Technical Field

The invention relates to the technical field of composite materials, in particular to a copper-nickel alloy, a preparation method and application thereof, and a two-dimensional material growth substrate.

Background

The two-dimensional material refers to a material in which electrons can only move freely (planar motion) on a two-dimensional nanoscale (1-100 nm), such as a nano-film, a superlattice, a quantum well, graphene and the like. The controllable preparation of high-quality and large-area two-dimensional materials is an important prerequisite for realizing the industrial application of the two-dimensional materials. Taking graphene as an example, a Chemical Vapor Deposition (CVD) method based on transition metal catalysis is the method most likely to achieve high-quality, large-area graphene synthesis among known methods. However, the quality of the graphene synthesized on the surface of a single metal copper or nickel catalyst by using a CVD method is still lower than expected value, and one of the main reasons is that the metal catalysts used for CVD growth of graphene have their advantages and disadvantages, and it is difficult to satisfy the conditions of fast growth speed, high quality and good uniformity of graphene.

An effective solution is to use a copper-nickel alloy catalyst, and experiments at present find that the alloy catalyst has special advantages in rapidly synthesizing high-quality large-area single crystal graphene. However, the copper-nickel substrate has the problems of surface roughness and edge wrinkling caused by stress in the high-temperature annealing alloying process, the roughness of the substrate surface can cause a large number of wrinkles to be formed in the graphene growth process, the electron mobility and the service performance of the graphene are affected, and the roughness of the substrate surface can cause the damage of the graphene transfer process. Moreover, the copper-nickel alloy foil obtained by electroplating in the current market is often polycrystalline, and the graphene grows by using the foil as a substrate, and a crystal boundary is introduced in the process of growing and splicing in a graphene domain, so that the quality of the graphene is reduced, and the uniformity of the quality of the graphene is reduced.

Therefore, the method for effectively obtaining the copper-nickel alloy substrate with good surface flatness is explored, and the method has important significance for further realizing and expanding the high-end application of the graphene.

It is noted that the information disclosed in the foregoing background section is only for enhancement of background understanding of the invention and therefore it may contain information that does not constitute prior art that is already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention provides a copper-nickel alloy, a preparation method and application thereof, and a two-dimensional material growth substrate, aiming at overcoming at least one defect of the prior art, and solving the problems that the quality of a two-dimensional material grown by using the copper-nickel alloy prepared by the prior method as a substrate, particularly graphene, is low, the transfer process is easy to damage, and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a preparation method of a copper-nickel alloy, which comprises the following steps: carrying out pre-annealing treatment on the copper foil; carrying out nickel plating treatment on the copper foil subjected to the pre-annealing treatment to obtain a copper-nickel composite foil; and annealing and alloying the copper-nickel composite foil to obtain the copper-nickel alloy.

According to one embodiment of the present invention, the copper foil is a polycrystalline copper foil or a single crystal copper foil, and the copper foil has a thickness of 10 to 100 μm.

According to one embodiment of the invention, the copper foil is a high index face single crystal copper foil.

According to one embodiment of the invention, the pre-annealing treatment is carried out in an inert atmosphere, the temperature of the pre-annealing treatment is 800-1050 ℃, and the time of the pre-annealing treatment is not less than 30 minutes.

According to one embodiment of the invention, the annealing alloying treatment is carried out in an inert atmosphere, the temperature of the annealing alloying treatment is 1000-1100 ℃, and the time of the annealing alloying treatment is not less than 1 hour.

According to one embodiment of the present invention, the method of the nickel plating treatment is selected from one or more of an electrochemical method, a magnetron sputtering method, a vapor deposition method, and a vacuum evaporation plating method.

According to one embodiment of the present invention, the thickness of the nickel obtained after the nickel plating treatment is 0.5 to 20 μm.

The invention also provides a copper-nickel alloy prepared by the method.

The invention also provides application of the copper-nickel alloy as a two-dimensional material growth substrate.

The invention also provides a two-dimensional material growth substrate which adopts the copper-nickel alloy.

According to the technical scheme, the invention has the beneficial effects that:

the invention provides a novel copper-nickel alloy and a preparation method thereof, wherein the copper-nickel alloy with the surface flatness Ra of less than 150nm can be obtained by carrying out pre-annealing treatment on a copper foil, and can be used as a substrate for growing a two-dimensional material, particularly for growing graphene, so that the quality of the graphene can be effectively improved. The method can also be used for simply obtaining the high-index surface copper-nickel alloy single crystal foil, has higher catalytic activity, can further improve the growth quality of the graphene, and reduces the transfer damage rate of the graphene. The method has the advantages of simple process, low cost and good application prospect.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a flow chart of a process for preparing a copper-nickel alloy in accordance with one embodiment of the present invention;

FIG. 2 is a three-dimensional image of the surface topography of a white light interferometer representation of the copper-nickel alloy of example 1;

FIG. 3 is a three-dimensional image of the surface topography of a white light interferometer representation of the copper-nickel alloy of example 2;

FIG. 4 is a normal antipole plot of an electron backscatter diffraction characterization of the high index (510) plane copper nickel alloy of example 2;

FIG. 5 is a three-dimensional image of the surface topography of a white light interferometer representation of the copper-nickel alloy of example 3;

FIG. 6 is a normal antipole plot of an electron backscatter diffraction characterization of the high index (441) plane CuNi alloy of example 3;

FIG. 7 is a three-dimensional image of the surface topography of a white light interferometer representation of the copper-nickel alloy of comparative example 1;

FIG. 8 is an optical microscope image of graphene grown on a copper-nickel alloy substrate of comparative example 1 transferred to a silicon wafer with mark;

FIG. 9 is an optical microscope image of graphene grown on a copper-nickel alloy substrate of example 1 transferred to a silicon wafer with mark;

fig. 10 is a raman spectrum of graphene grown on the copper-nickel alloy substrate of example 2.

Detailed Description

The following presents various embodiments or examples in order to enable those skilled in the art to practice the invention with reference to the description herein. These are, of course, merely examples and are not intended to limit the invention. The endpoints of the ranges and any values disclosed in the present application are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to yield one or more new ranges of values, which ranges of values should be considered as specifically disclosed herein.

The invention provides a preparation method of a copper-nickel alloy, and fig. 1 shows a flow chart of a preparation process of the copper-nickel alloy according to an embodiment of the invention, and as shown in fig. 1, the preparation method of the copper-nickel alloy comprises the following steps: carrying out pre-annealing treatment on the copper foil; carrying out nickel plating treatment on the copper foil subjected to the pre-annealing treatment to obtain a copper-nickel composite foil; and annealing and alloying the copper-nickel composite foil to obtain the copper-nickel alloy.

According to the invention, the copper-nickel alloy is a common two-dimensional material growth substrate, and the prior method generally adopts electroplating nickel on a copper foil and then annealing at high temperature to obtain the copper-nickel alloy. However, the high temperature annealing alloying process often has the problems of surface roughness and edge wrinkling of the material caused by excessive stress, and further influences the quality of the grown two-dimensional material. The inventor of the invention finds that in the process of preparing the copper-nickel alloy, the copper foil is pre-annealed to release most of residual stress in the copper foil in advance, and in the process of annealing and alloying after the subsequent nickel plating of the copper foil, because the residual stress of the copper foil is released in the pre-annealing process, the total stress caused by the mixing and dissolving process of the copper and the nickel is small, the problems of rough surface and edge curling are well inhibited, and the copper-nickel alloy with the surface flatness Ra less than 150nm is obtained. When the copper-nickel alloy with the surface flatness level is used as a two-dimensional material growth substrate, particularly graphene growth, the formation of multi-layer graphene small cores and graphene wrinkles can be effectively reduced, the graphene quality is improved, and the graphene transfer damage rate is reduced.

The following specifically explains the copper-nickel alloy and the preparation process thereof, and specifically explains the influence and effect of the copper-nickel alloy as a substrate on a two-dimensional material grown thereon by taking the two-dimensional material as graphene as an example.

Firstly, a copper foil is provided and is subjected to pre-annealing treatment. Wherein the copper foil is commercially available, the present invention is not limited thereto. The copper foil may be a polycrystalline copper foil or a single crystal copper foil, and the thickness of the copper foil is generally between 10 μm and 100. mu.m, for example, 10 μm, 20 μm, 30 μm, 35 μm, 40 μm, 45 μm, 60 μm, 70 μm, 80 μm, 96 μm, 100 μm, or the like. Preferably, the copper foil used is a single crystal copper foil, more preferably a high index face single crystal copper foil. The high-index-surface single crystal copper foil is a single crystal copper foil with at least one crystal face index larger than 1. The growth quality of the graphene can be effectively improved by adopting the high-index-surface single crystal copper foil, and the transfer damage rate of the graphene can be further reduced.

In this embodiment, the copper foil may be placed in a tube furnace, and an inert gas of 300sccm to 1000sccm, for example, hydrogen gas, argon gas, or the like, or a mixed gas thereof may be introduced, and the working pressure may be low (about 200Pa to 800Pa) or normal pressure. And then heating the copper foil to the pre-annealing treatment temperature, wherein the heating process generally lasts for 20-60 min.

In some embodiments, the pre-annealing temperature is 800 ℃ to 1050 ℃, for example, 800 ℃, 850 ℃, 900 ℃, 920 ℃, 980 ℃, etc., and too high a temperature can cause the copper foil to melt, and too low a temperature can cause insufficient stress relief in the copper foil. The time of the pre-annealing treatment is not less than 30 minutes, such as 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours and the like, and the time below the time is not enough to release the stress in the copper foil, but the time is not too long, and can be determined according to actual needs.

And then, after the pre-annealing treatment is finished, the flow of the introduced inert gas is kept unchanged, and the temperature is reduced to ensure that the copper foil is not oxidized. And cooling to room temperature, taking out the soft copper foil subjected to the pre-annealing treatment, and carrying out nickel plating treatment on the soft copper foil.

According to the present invention, the method of the nickel plating treatment includes, but is not limited to, an electrochemical method, a magnetron sputtering method, a vapor deposition method, a vacuum evaporation plating method, and the like or a combination thereof. Preferably, electrochemical nickel plating is used. After nickel plating, a nickel layer having a thickness of 0.5 to 20 μm, for example, 0.5 to 1 μm, 3 μm, 5 μm, 10 μm, or 20 μm is formed on the soft copper foil, thereby obtaining a copper-nickel composite foil.

And finally, carrying out annealing alloying treatment on the copper-nickel composite foil to obtain the copper-nickel alloy. In this embodiment, the copper-nickel composite foil may be placed in a tube furnace, and an inert gas of 300sccm to 1000sccm, for example, hydrogen gas, argon gas, or the like, or a mixed gas thereof may be introduced, and the working pressure may be low (200Pa to 800Pa) or normal pressure. And then heating the copper-nickel composite foil to the annealing alloying treatment temperature, wherein the heating process lasts for 20-60 min generally.

In some embodiments, the annealing alloying temperature is 1000 ℃ to 1100 ℃, e.g., 1000 ℃, 1030 ℃, 1050 ℃, 1080 ℃, 1100 ℃, etc. The time of the annealing alloying treatment is not less than 1 hour, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours and the like, and below this time, annealing is not completed and alloying is effective. And after the annealing is finished, keeping the flow of the introduced inert gas unchanged until the temperature is reduced to the room temperature, and obtaining the copper-nickel alloy.

In conclusion, the copper foil is firstly subjected to pre-annealing treatment before the copper-nickel annealing alloying treatment, so that the problems of foil curling and surface roughening caused by excessive residual stress of copper-nickel atoms in the annealing alloying process can be effectively solved, the copper-nickel alloy substrate with the surface flatness of Ra less than 150nm is obtained, and the formation of multi-layer graphene nuclei and the formation of graphene wrinkles are effectively reduced. The growth quality of the graphene is improved. In addition, the initial copper foil material is replaced by the high-index-surface single crystal copper foil, the high-index-surface single crystal copper foil can be simply converted into the high-index-surface copper-nickel alloy single crystal foil by the method, the growth quality of graphene can be further improved on the surface of the single crystal substrate, and the transfer damage rate of the graphene can be reduced. The method disclosed by the invention is simple in process and low in cost, and has important significance in further realizing and expanding high-end application of graphene.

The invention will be further illustrated by the following examples, but is not to be construed as being limited thereto. Unless otherwise specified, reagents, materials and the like used in the present invention are commercially available.