Method for growing graphene

Abstract

The invention relates to a method for growing graphene. The method comprises the following steps: removing impurities on the surface of a copper substrate by introducing a plasma oxidizing atmosphere; maintaining a plasma oxidizing atmosphere, and growing graphene on the surface of the copper substrate by adopting a chemical vapor deposition method; wherein a carbon source used for growing the graphene is a solid carbon source, and the solid carbon source can be obtained by mixing an aromatic compound and solid graphene. According to the method, impurities on the surface of copper can be efficiently removed by using plasma, the low-temperature graphene growth efficiency is improved, rapid cracking of a solid carbon source can be promoted, meanwhile, graphene powder or graphene sheets are introduced to serve as an adsorption carrier of aromatic compounds, the cracking speed can be effectively adjusted, and the graphene quality can be improved. According to the method, the graphene is grown on the copper connector by using the solid carbon source, so that the selection range of a graphene growth substrate is widened, and a wider development prospect is developed for a graphene and copper material combined product.

Description

Technical Field

[0001] The invention relates to the field of low-dimensional materials and new materials, and in particular to a method for growing graphene. Background Art

[0002] In the field of power electronics, copper and silver are widely used as key conductor materials. With the vigorous development of the new energy industry, more and more application scenarios have put forward higher requirements for conductor resistance and working life under high current. However, copper is easy to oxidize and has high resistance at high temperature, which cannot meet the higher requirements in high current scenarios. Silver has small reserves in nature and is not suitable for large-scale application. Graphene has excellent conductivity and chemical stability, strong corrosion resistance, and is an ideal conductor material.

[0003] Graphene is a two-dimensional material composed of a single layer of carbon atoms with excellent electrical, thermal and mechanical properties. It is one of the thinnest, strongest and hardest nanomaterials known so far, with extremely high strength and excellent flexibility. Due to its unique crystal structure and electronic behavior, graphene has shown great application potential in materials science, electronics, energy, biomedicine and other fields. The excellent properties of graphene give it a wide range of application prospects in the manufacture of ultra-micro transistors, new generation solar cells, biosensors, etc., and it is expected to lead the direction of a new round of scientific and technological revolution and industrial transformation. At the same time, graphene is environmentally friendly, can be prepared at room temperature and pressure, and has the characteristics of sustainable development.

[0004] The preparation method of graphene has always been the focus of research, among which chemical vapor deposition (CVD) is a commonly used preparation method. The CVD method can generate graphene by heating a gas carbon source, such as methane, acetylene, etc., at high temperature on a metal substrate. However, this method requires the use of high-purity gas, and the reaction conditions are relatively harsh, such as high temperature and high pressure, so the preparation cost is high. In addition, the CVD method may also cause problems such as environmental pollution and potential safety hazards. Therefore, it is of great practical significance to find a low-cost, high-efficiency, high-quality, environmentally friendly and safe method for preparing graphene. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for growing graphene to solve one or more of the above problems, comprising the following steps:

[0006] Impurities on the surface of the copper substrate are removed by introducing a plasma oxidation atmosphere;

[0007] Maintaining a plasma oxidation atmosphere, and growing graphene on the surface of the copper substrate by chemical vapor deposition;

[0008] The carbon source used for growing graphene is a solid carbon source, and the solid carbon source can be obtained by mixing an aromatic compound with solid graphene.

[0009] Preferably, the mixing of the aromatic compound with the solid graphene comprises:

[0010] dissolving a solid aromatic compound in an ethanol solvent, mixing the solid graphene with the solid graphene, and then evaporating the mixture to obtain the solid carbon source;

[0011] The weight ratio of the solution containing the solid aromatic compound to the solid graphene is (0.1-10):100, and the preferred weight ratio is: (5-10):100;

[0012] Preferably, the solid aromatic compound includes at least one of naphthalene, anthracene, phenanthrene, aniline, phenylenediamine, benzidine, diazonium, quinoline and o-phenanthroline.

[0013] Preferably, the mixing of the aromatic compound with the solid graphene comprises:

[0014] The solid graphene includes graphene powder, and the liquid aromatic compound is mixed with the graphene powder to obtain the solid carbon source;

[0015] Wherein, the weight ratio of the liquid aromatic compound to the graphene powder is (0.1-10):100, and the preferred weight ratio is: (5-10):100.

[0016] Preferably, the liquid aromatic compound includes at least one of benzene, toluene, xylene, pyrrole, nitrobenzene, benzyl cyanide and bipyridine.

[0017] Preferably, in the process of removing impurities on the surface of the copper substrate by introducing an oxidizing atmosphere of plasma, the pressure range is controlled to be 0.1-100 Pa; the heating temperature is controlled to be 100-400° C., and the heating time is controlled to be 10-200 s.

[0018] Preferably, the solid graphene comprises a graphene sheet, and the specific surface area of ​​the graphene sheet is 300 to 1000 m 2 / g, number of layers <5.

[0019] Preferably, the reaction temperature for growing graphene is 250-600°C, preferably 300-500°C, and the best reaction temperature is 400°C.

[0020] Preferably, the reaction time for growing graphene is 10 to 600 min, the preferred reaction time is 60 to 180 min, and the optimal reaction time is 60 min.

[0021] Preferably, the operation of removing impurities from the surface of the copper substrate and the operation of growing graphene on the surface of the copper substrate are both carried out in a tubular furnace reaction chamber; the solid carbon source is brought in by a protective gas introduced into the tubular furnace reaction chamber, the protective gas is a mixture of at least one of nitrogen or argon and hydrogen, the proportion of hydrogen in the mixed gas is 1% to 100%, the preferred proportion of hydrogen in the mixed gas is 3%-10%, the optimal proportion of hydrogen in the mixed gas is 5%, the gas flow rate of the protective gas is 5 to 500 sccm, the preferred flow rate is 100 to 200 sccm, and the optimal flow rate is 100 sccm.

[0022] Preferably, the copper substrate includes copper foil, copper wire, copper plate, copper block, copper piece, the copper substrate includes regular shape and irregular shape, and the copper piece is a part or product made of copper with a certain shape and specification.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention can quickly and efficiently remove impurities on the surface of the copper substrate by using a plasma atmosphere, significantly improving the efficiency of low-temperature growth of graphene. The plasma atmosphere runs through the entire graphene growth process. Since the active particles in the plasma have high energy, they can promote the rapid cracking of the solid carbon source, but this may cause the supply of the carbon source to be difficult to accurately control, thereby making the growth rate too fast, affecting the quality of the final graphene product. In this regard, the present invention introduces graphene powder or graphene sheets as adsorption carriers of aromatic compounds. This method can effectively regulate the cracking rate and ensure the uniform supply of the carbon source, thereby helping to improve the quality of graphene during the growth process. In other words, the present invention promotes the cracking of the solid carbon source and controls the cracking rate of graphene powder or graphene sheets by a plasma oxidation atmosphere. The combination of these two means takes into account the speed and quality of graphene growth.

[0025] The present invention uses a solid aromatic compound and graphene powder or graphene sheet mixed and evaporated to obtain a solid carbon source or a liquid aromatic compound converted into a solid carbon source as a carbon source for growing graphene. Compared with traditional CVD graphene growth methods, the present invention reduces steps such as controlling the flow rate of reaction gas and simplifies the operation process.

[0026] The present invention uses a solid carbon source to grow graphene on a copper connector, successfully broadening the application scope of graphene growth substrates. This technological advancement means that graphene can be grown on the surface of copper connectors and copper plug-ins, thus opening up a broader development prospect for products combining graphene and copper materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 is a logic flow chart of a method for growing graphene in one embodiment of the present invention;

[0029] Figure 2 This is a diagram showing the effect of growing graphene on a copper connector in one embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] This article relates to numerical intervals. If not otherwise specified, the above numerical intervals are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Within the range allowed by the error before and after the interval range, they all fall within the protection scope of the present application. Further, when the range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges included therein.

[0033] The temperature parameters herein, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows for temperature fluctuations within the precision range of instrument control.

[0034] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0035] Figure 1 is a logical flow chart of the method for growing graphene of the present invention, such as Figure 1 As shown, in a specific embodiment of the present invention, a method for growing graphene is provided, the method comprising the following steps:

[0036] S1. Remove impurities on the surface of the copper substrate by introducing a plasma oxidation atmosphere.

[0037] S2, maintaining a plasma oxidation atmosphere, and growing graphene on the surface of the copper substrate by chemical vapor deposition;

[0038] The carbon source used for graphene growth is a solid carbon source, which is obtained by dissolving an aromatic compound in a solvent, mixing the mixture with graphene powder or graphene sheets, and then evaporating the mixture to dryness.

[0039] In some embodiments of the present invention, the processes of removing impurities from the surface of the copper substrate and growing graphene on the surface of the copper substrate are both performed in a tubular furnace reaction chamber.

[0040] In some embodiments of the present invention, the copper substrate includes but is not limited to copper devices such as copper foil, copper wire, copper plate, copper block, copper connector and copper plug-in. The copper device is a part or product with a certain shape and specification made of copper, and the copper includes regular shapes and irregular shapes.

[0041] In some embodiments of the present invention, the method of introducing a plasma oxidizing atmosphere comprises:

[0042] After placing the copper substrate in the reaction chamber of the tubular furnace, evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to start glowing. It is well known to people in this field that the presence of glow means that there is plasma in the atmosphere, thereby generating and maintaining an oxidizing atmosphere of plasma.

[0043] In some embodiments of the present invention, during the process of removing impurities on the surface of the copper substrate using plasma, the pressure range of the tube furnace is controlled to be 0.1-100 Pa; under near-vacuum conditions, easily volatile attached organic impurities will volatilize first.

[0044] In some specific examples, the pressure may be 0.1Pa, 1Pa, 20Pa, 40Pa, 60Pa, 80Pa, 100Pa, etc.

[0045] Furthermore, the heating temperature of the tube furnace is controlled to be 100-400° C., and the heating time is 10-200 seconds. Since the plasma has a fast processing speed for the attachments on the surface of the copper substrate, the surface of the copper substrate can be cleaned by heating for 10-200 seconds, while the copper substrate may not be cleaned if the heating temperature is lower than 100° C. and the heating time is lower than 10 seconds, and the copper substrate may not be cleaned if the heating temperature is higher than 400° C. and the heating time is higher than 200 seconds, which may cause the copper substrate surface to be corroded by the oxidizing atmosphere.

[0046] In some specific examples, the heating temperature can be 100°C, 200°C, 300°C, 400°C, etc., and the heating time can be 10s, 30s, 50s, 70s, 90s, 110s, 130s, 150s, 170s, 190s, 200s, etc.

[0047] In some embodiments of the present invention, an aromatic compound is dissolved in an organic solvent and mixed with graphene powder in a weight ratio of (0.1-10):100, preferably (5-10):100; and the mixture is evaporated to dryness using a RE 5298A rotary evaporator, wherein the graphene powder or graphene sheet can be used as an adsorption carrier for the aromatic compound. When the mixing ratio is greater than 10:100, the graphene powder or graphene sheet may not be able to fully adsorb the aromatic compound, resulting in too fast a carbon source supply and uncontrollable growth rate; when the mixing ratio is less than 0.1:100, too much graphene powder or graphene sheet may slow down the release rate of the carbon source, resulting in too slow a growth rate of graphene.

[0048] In some embodiments of the present invention, the graphene may be graphene powder or graphene sheet, and the specific surface area of ​​the graphene sheet is 300 to 1000 m 2 / g, number of layers <5. Graphene sheet specific surface area is less than 300m 2 / g may make the adsorption capacity of graphene sheets insufficient to effectively adsorb liquid aromatic compounds, resulting in too fast supply of carbon source, affecting the growth quality and uniformity of graphene; greater than 1000m 2 / g may lead to excessive use of graphene sheets and increase material costs.

[0049] In some specific examples, the specific surface area of ​​the graphene sheet can be 300m 2 / g, 400m 2 / g、500m 2 / g、600m 2 / g、700m 2 / g、800m 2 / g、900m 2 / g、1000m 2 / g, etc.; the number of layers can be 1, 2, 3 or 4. The graphene sheets with large specific surface area are conducive to retaining aromatic compounds and better play the role of adsorption carrier.

[0050] In some embodiments of the present invention, plasma runs through the entire graphene growth process. In the chemical vapor deposition (CVD) growth process of graphene, the plasma environment plays a key catalytic role in the decomposition of the solid carbon source. Since the active particles in the plasma have high energy, they can promote the rapid cracking of the solid carbon source, but this may make the supply of the carbon source difficult to accurately control, thereby making the growth rate too fast, affecting the quality of the final graphene product.

[0051] The present invention introduces graphene powder or graphene sheet as an adsorption carrier of aromatic compounds. This method can effectively adjust the cracking rate and ensure the uniform supply of carbon source, thereby helping to improve the quality of graphene during the growth process. In this way, the growth of graphene in the CVD process can be better controlled to obtain a graphene material with excellent performance.

[0052] In some embodiments of the present invention, the solvent is selected from ethanol.

[0053] In some embodiments of the present invention, the solid aromatic compound includes at least one of naphthalene, anthracene, phenanthrene, aniline, phenylenediamine, benzidine, diazonium, quinoline, and o-phenanthroline.

[0054] In some embodiments of the present invention, the solid carbon source can be obtained by converting a liquid aromatic compound, and the liquid aromatic compound includes at least one of benzene, toluene, xylene, pyrrole, nitrobenzene, phenylacetonitrile, and bipyridine.

[0055] Specifically, converting liquid aromatic compounds into solid carbon sources includes:

[0056] The liquid aromatic compound is mixed with graphene powder, and the graphene adsorbs the liquid aromatic compound to achieve the purpose of slowly diffusing into the growth atmosphere. The weight ratio of the liquid aromatic compound to the graphene powder is (0.1-10):100, and the preferred ratio is: (5-10):100. When the mixing ratio is less than 0.1:100, too much graphene powder or graphene sheets may slow down the release rate of the carbon source, resulting in too slow growth of graphene; when it is higher than 10:100, the excess of liquid aromatic compounds may make the growth process difficult to control, increasing the risk of generating defects or non-uniform structures.

[0057] In some specific examples, the weight ratio of the liquid aromatic compound to the graphene powder can be: 0.1:100, 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100, 10:100, etc.

[0058] In some embodiments of the present invention, the reaction temperature of the solid carbon source and the copper substrate is 250-600° C., preferably 300-500° C., and optimally 400° C. The reaction cannot occur at a temperature lower than 250° C., and the copper substrate may be deformed at a temperature higher than 600° C.

[0059] In some specific examples, the reaction temperature of the solid carbon source and the copper substrate can be 250° C., 300° C., 400° C., 500° C., 600° C., etc.

[0060] In some embodiments of the present invention, the reaction time of the solid carbon source and the copper substrate is 10 to 600 minutes, preferably 60 to 180 minutes, and the best time is 60 minutes. If the reaction time is less than 10 minutes, a complete graphene layer may not be formed on the surface of the copper part, affecting its conductivity and anti-oxidation performance; prolonged reaction time will increase energy consumption and increase production costs.

[0061] In some specific examples, the reaction time of the solid carbon source and the copper substrate is 10 min, 100 min, 200 min, 400 min, 600 min, etc.

[0062] In some embodiments of the present invention, 0.1 g of the solid carbon source mixed graphene powder is brought in by the protective gas introduced into the reaction chamber of the tubular furnace, and this process is carried out along with the growth process. The protective gas is a mixture of nitrogen or argon and hydrogen, and the proportion of hydrogen in the mixed gas is 1% to 100%, and the preferred proportion of hydrogen in the mixed gas is: 3%-10%, and the optimal proportion of hydrogen in the mixed gas is 5%. The gas flow rate of the protective gas is 5 to 500 sccm, the preferred flow rate is: 100 to 200 sccm, and the optimal flow rate is 100 sccm. A small amount of hydrogen is introduced during the reaction of growing graphene. Since the diffusion rate of hydrogen is very fast, the reduction reaction is prioritized over the reaction of generating graphene, so that the oxides generated on the surface of the copper substrate during the pretreatment process can be reduced without interfering with the growth of graphene. The proportion of hydrogen in the mixed gas is less than 1%, which makes its reduction ability insufficient. If the proportion is too high, it will increase the danger and interfere with the reaction of generating graphene. A gas flow rate of the shielding gas lower than 5 sccm may result in the inability to effectively transfer the solid carbon source to the reaction chamber, affecting the growth of graphene; a gas flow rate of the shielding gas higher than 500 sccm may cause a heavy load on the furnace body and the conveying system, shorten the equipment life, cause gas waste, and increase production costs.

[0063] In some specific examples, the ratio of hydrogen to the mixed gas can be 1%, 50%, 100%, etc.; the gas flow rate of the protective gas can be 5 sccm, 50 sccm, 500 sccm, etc.

[0064] In some embodiments of the present invention, the protective gas includes: an inert gas and hydrogen, and the inert gas includes at least one of argon and nitrogen, that is, the inert gas is all argon, or all nitrogen, or argon and nitrogen are composed of each other. The embodiments of the present invention do not specifically limit the ratio of argon and nitrogen.

[0065] It should be clear that the use of the process provided by the embodiment of the present invention or the replacement or change of conventional data all fall within the protection scope and disclosure scope of the present invention.

[0066] The present application is described below through specific embodiments.

[0067] Example 1

[0068] (1) Clean the surface of the copper connector;

[0069] Place the copper connector in a tube furnace and evacuate to high vacuum, even if the pressure in the reaction chamber drops below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0070] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa. Finally, the heating temperature of the tube furnace is controlled at 100° C. and heated for 10 seconds.

[0071] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0072] 0.1 g of o-phenanthroline (solid aromatic compound) was dissolved in 500 ml of ethanol solvent, 0.1 ml of the solution was selected and mixed with 8 g of graphene powder, and the mixed solution was poured into a RE 5298A rotary evaporator and evaporated to dryness to obtain a solid carbon source.

[0073] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0074] The plasma oxidizing atmosphere in the tube furnace is maintained unchanged, and a protective gas with a ratio of hydrogen to inert gas of 5:95 is introduced. The gas flow rate is controlled to be 100 sccm, and the solid carbon source heated to 60° C. is gasified and sent into the tube furnace through the protective gas.

[0075] (4) Growing graphene on copper connectors;

[0076] The tubular furnace was adjusted so that the graphene growth temperature was 400° C. and the reaction time was controlled to be 60 min, thereby obtaining a graphene copper piece 1 .

[0077] Example 2

[0078] (1) Clean the surface of the copper connector;

[0079] First, place the copper connector in a tube furnace and evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0080] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa, the heating temperature of the tube furnace is controlled at 300° C., and the heating is performed for 10 seconds.

[0081] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0082] Dissolve 0.1 g of o-phenanthroline (a solid aromatic compound) in 500 ml of ethanol solvent, select 0.1 ml of this solution and mix it with 1.6 g of a solid with a specific surface area of ​​1000 m 2 / g, and 4-layer graphene sheets were mixed, and the mixed solution was poured into a RE 5298A rotary evaporator to evaporate to dryness to obtain a solid carbon source.

[0083] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0084] The oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled to be 100 sccm, and a solid carbon source at a temperature of 60° C. was fed into the tubular furnace.

[0085] (4) Growing graphene on copper connectors;

[0086] The tubular furnace was adjusted so that the graphene growth temperature was 600° C. and the reaction time was controlled to be 600 min, thereby obtaining a graphene copper piece 2 .

[0087] Example 3

[0088] (1) Clean the surface of the copper connector;

[0089] First, place the copper connector in a tube furnace and evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0090] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa, the heating temperature of the tube furnace is controlled at 300° C., and the heating is performed for 10 seconds.

[0091] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0092] Dissolve 0.1 g of o-phenanthroline (a solid aromatic compound) in 500 ml of ethanol solvent, select 0.1 ml of this solution and mix it with 1.6 g of a solid with a specific surface area of ​​300 m 2 / g, and 1 layer of graphene sheets, the mixed solution was poured into a RE 5298A rotary evaporator, and evaporated to dryness to obtain a solid carbon source.

[0093] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0094] The oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled to be 100 sccm, and a solid carbon source at a temperature of 60° C. was fed into the tubular furnace.

[0095] (4) Growing graphene on copper connectors;

[0096] The tubular furnace was adjusted so that the graphene growth temperature was 250° C. and the reaction time was 10 min, thereby obtaining a graphene copper piece 3.

[0097] Example 4

[0098] (1) Clean the surface of the copper connector;

[0099] First, place the copper connector in a tube furnace and evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0100] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa. Finally, the heating temperature of the tube furnace is controlled at 100° C. and heated for 100 seconds.

[0101] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0102] 0.1 g of o-phenanthroline (solid aromatic compound) was dissolved in 500 ml of ethanol solvent, 0.1 ml of the solution was selected and mixed with 1.6 g of graphene powder, and the mixed solution was poured into a RE 5298A rotary evaporator and evaporated to dryness to obtain a solid carbon source.

[0103] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0104] The oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled to be 100 sccm, and a solid carbon source at a temperature of 60° C. was fed into the tubular furnace.

[0105] (4) Growing graphene on copper connectors;

[0106] The tubular furnace was adjusted so that the graphene growth temperature was 500° C. and the reaction time was 60 min, thereby obtaining a graphene copper piece 4 .

[0107] Example 5

[0108] (1) Clean the surface of the copper connector;

[0109] First, place the copper connector in a tube furnace and evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0110] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa, the heating temperature of the tube furnace is controlled at 400° C., and the heating is performed for 100 seconds.

[0111] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0112] 0.1 g of o-phenanthroline (solid aromatic compound) was dissolved in 500 ml of ethanol solvent, 9 ml of the liquid was selected and mixed with 91 g of graphene powder, and the mixed solution was poured into a RE 5298A rotary evaporator and evaporated to dryness to obtain a solid carbon source.

[0113] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0114] The oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled to be 100 sccm, and a solid carbon source at a temperature of 60° C. was fed into the tubular furnace.

[0115] (4) Growing graphene on copper connectors;

[0116] The tubular furnace was adjusted so that the graphene growth temperature was 400° C. and the reaction time was 60 min, thereby obtaining a graphene copper piece 5 .

[0117] Example 6

[0118] (1) Clean the surface of the copper connector;

[0119] First, place the copper connector in a tube furnace and evacuate to high vacuum, that is, reduce the pressure of the reaction chamber to below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0120] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa, the heating temperature of the tube furnace is controlled at 100° C., and the heating is performed for 100 seconds.

[0121] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0122] 0.1 g of o-phenanthroline (solid aromatic compound) was dissolved in 500 ml of ethanol solvent, 9 ml of liquid and 91 g of graphene powder were selected for mixing, and the mixed solution was poured into a RE 5298A rotary evaporator and evaporated to dryness to obtain a solid carbon source.

[0123] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0124] The oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled to be 100 sccm, and a solid carbon source at a temperature of 60° C. was fed into the tubular furnace.

[0125] (4) Growing graphene on copper connectors;

[0126] The tubular furnace was adjusted so that the graphene growth temperature was 300° C. and the reaction time was 60 min, thereby obtaining a graphene copper piece 6 .

[0127] Comparative Example 1 (no plasma and no graphene powder)

[0128] (1) Clean the surface of the copper connector;

[0129] The copper substrate was cleaned with alcohol before treatment.

[0130] (2) converting the aromatic compound, alcohol and graphene powder / sheet into a solid carbon source;

[0131] 0.1 g of o-phenanthroline was dissolved in 500 ml of ethanol solvent, and the mixed solution was poured into a RE 5298A rotary evaporator to evaporate to dryness to obtain a solid carbon source.

[0132] (3) bringing a solid carbon source into the tube furnace through a protective gas;

[0133] The evaporated solid carbon source was placed in the raw material heating zone, the oxidizing atmosphere of the plasma was maintained unchanged, a protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, the gas flow rate was controlled at 100 sccm, and the solid carbon source at a temperature of 40°C was fed into the tubular furnace.

[0134] (3) Growing graphene on copper connectors;

[0135] The tubular furnace was adjusted so that the graphene growth temperature was 400° C. and the reaction time was 60 min, thereby obtaining a graphene copper piece 7 .

[0136] Comparative Example 2 (100 / 100 solid carbon source without graphene powder)

[0137] (1) Clean the surface of the copper connector;

[0138] Place the copper connector in a tube furnace and evacuate to high vacuum, even if the pressure in the reaction chamber drops below 1Pa, and then turn on the plasma power supply to ignite, thereby generating and maintaining the oxidizing atmosphere of the plasma;

[0139] The pressure of the tube furnace into which the plasma oxidation atmosphere is introduced is controlled at 1 Pa. Finally, the heating temperature of the tube furnace is controlled at 100° C. and heated for 100 seconds.

[0140] (2) bringing o-phenanthroline into the tubular furnace by means of a protective gas;

[0141] A protective gas with a ratio of hydrogen to inert gas of 5:95 was introduced, and at a gas flow rate of 100 sccm, o-phenanthroline at a temperature of 40° C. was fed into the tube furnace.

[0142] (3) Growing graphene on copper connectors;

[0143] The tubular furnace was adjusted so that the graphene growth temperature was 400° C. and the reaction time was 60 min, thereby obtaining copper-based graphene 8.

[0144] The performance comparison of the graphene / copper parts 1-8 obtained in Examples 1-4 and Comparative Examples 1-2 is shown in the following table:

[0145] Table 1 Performance parameters of graphene / copper parts of Examples 1-4 and Comparative Examples 1-2

[0146]

[0147]

[0148] Figure 2 is a diagram showing the effect of growing graphene on a copper connector in one embodiment of the present invention. From the above embodiments, comparative examples and data tables 1 and Figure 2 It can be seen that whether to add graphene sheets and graphene powder to the solid carbon source has a great influence on the growth of graphene. The ratio of aromatic compounds dissolved in ethanol mixed solution: graphene powder / sheets has little effect on the results. Graphene powder has a better growth effect than sheets.

[0149] In this process, the growth efficiency and quality of the tube furnace at 400℃ under negative pressure for 60 minutes are both strong.

[0150] In the process of growing graphene on copper connectors and plug-ins, turning on plasma excitation and using graphene as an adsorption carrier of solid carbon sources can effectively control the cracking rate and ultimately grow high-quality graphene connectors.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for growing graphene, characterized in that: include: Impurities on the surface of the copper substrate are removed by introducing a plasma oxidation atmosphere; Maintaining a plasma oxidation atmosphere, and growing graphene on the surface of the copper substrate by chemical vapor deposition; The carbon source used for growing graphene is a solid carbon source, and the solid carbon source can be obtained by mixing an aromatic compound with solid graphene.

2. The method for growing graphene according to claim 1, characterized in that: The mixing of the aromatic compound with the solid graphene comprises: dissolving a solid aromatic compound in an ethanol solvent, mixing the solid graphene with the solid graphene, and then evaporating the mixture to obtain the solid carbon source; The weight ratio of the solution containing the solid aromatic compound to the solid graphene is (0.1-10):100, and the preferred weight ratio is: (5-10):100; Preferably, the solid aromatic compound includes at least one of naphthalene, anthracene, phenanthrene, aniline, phenylenediamine, benzidine, diazonium, quinoline and o-phenanthroline.

3. The method for growing graphene according to claim 1, characterized in that: The mixing of the aromatic compound with the solid graphene comprises: The solid graphene includes graphene powder, and the liquid aromatic compound is mixed with the graphene powder to obtain the solid carbon source; Wherein, the weight ratio of the liquid aromatic compound to the graphene powder is (0.1-10):100, and the preferred weight ratio is: (5-10):

100.

4. The method for growing graphene according to claim 3, characterized in that: The liquid aromatic compound includes at least one of benzene, toluene, xylene, pyrrole, nitrobenzene, benzyl cyanide and bipyridine.

5. The method for growing graphene according to claim 1, characterized in that: In the process of removing impurities on the surface of the copper substrate by introducing an oxidizing atmosphere of plasma, the pressure range is controlled to be 0.1-100 Pa; the heating temperature is controlled to be 100-400° C., and the heating time is controlled to be 10-200 s.

6. The method for growing graphene according to claim 1, characterized in that: The solid graphene includes graphene sheets, and the specific surface area of ​​the graphene sheets is 300 to 1000 m 2 / g, number of layers <5.

7. The method for growing graphene according to claim 1, characterized in that: The reaction temperature for growing graphene is 250-600°C, preferably 300-500°C, and the best reaction temperature is 400°C.

8. The method for growing graphene according to claim 1, characterized in that: The reaction time for growing graphene is 10 to 600 min, preferably 60 to 180 min, and the best reaction time is 60 min.

9. The method for growing graphene according to claim 1, characterized in that: The operation of removing impurities from the surface of the copper substrate and the operation of growing graphene on the surface of the copper substrate are both performed in a tubular furnace reaction chamber; The solid carbon source is brought in by the protective gas introduced into the reaction chamber of the tubular furnace. The protective gas is a mixture of at least one of nitrogen or argon and hydrogen. The proportion of hydrogen in the mixed gas is 1% to 100%, the preferred proportion of hydrogen in the mixed gas is 3% to 10%, the optimal proportion of hydrogen in the mixed gas is 5%, the gas flow rate of the protective gas is 5 to 500 sccm, the preferred flow rate is 100 to 200 sccm, and the optimal flow rate is 100 sccm.

10. The method for growing graphene according to claim 1, characterized in that: The copper substrate includes copper foil, copper wire, copper plate, copper block and copper piece. The copper substrate includes regular shape and irregular shape. The copper piece is a part or product made of copper with certain shape and specification.

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