KR102164300B1 - Method and apparatus for separating graphene, and method and apparatus for forming graphene layer - Google Patents

Abstract

The graphene separation method of the present invention is to solve the conventional problem, by applying a magnetic field to a container containing graphite particles, graphene, and a solvent, by the magnetic field, in the solvent, the graphite particles and the graphene And a separation process of separating at different positions, and a extraction process of removing the solvent and the graphene from a discharge port formed in the container.

Description

Graphene separation method, graphene separation device, graphene layer formation method, and graphene layer formation device TECHNICAL FIELD [METHOD AND APPARATUS FOR SEPARATING GRAPHENE, AND METHOD AND APPARATUS FOR FORMING GRAPHENE LAYER}

The present invention relates to a separation of graphene applicable to a transparent electrode, a battery electrode, and a semiconductor device, and a separation device thereof, a method of forming a graphene layer, and a formation device thereof.

Graphene is attracting attention as a material exhibiting very specific physical properties. The unique properties of graphene include high electron mobility, high thermal conductivity, high strength, and high light transmittance, and thus have many attractive properties. This unique property is expected to be useful as a new electronic device or nanotechnology material.

As a conventional method for forming graphene, there is a chemical vapor deposition method (Patent Document 1), and graphene produced by the chemical vapor deposition method can be transferred to a substrate and used for transparent electrodes and semiconductor devices.

10 to 13 show a method for forming graphene using the conventional chemical vapor deposition method described in Patent Document 1.

10 shows a method of forming graphene using a chemical vapor deposition method. On the substrate 1201, a catalyst layer 1202 is formed. As the substrate 1201, a silicon substrate 1201 having a thickness of 650 μm or the like is used. Before the catalyst layer 1202 is formed, the silicon substrate 1201 may be oxidized to form a silicon oxide layer having a thickness of 100 to 300 nm.

The catalyst layer 1202 is formed on the substrate 1201 by sputtering any one of metal materials composed of nickel (Ni), iron (Fe), cobalt (Co), platinum (Pt), and ruthenium (Ru). Can be formed. The catalyst layer 1202 is formed to have a thickness of approximately 100 to 150 nm.

Next, on the catalyst layer 1202, a graphene layer 1203 is formed. The graphene layer 1203 is formed by chemical vapor deposition of a source gas (CH ₄ , C ₂ H ₂ , C ₂ H ₄ , CO, etc.) containing carbon, for example. The graphene layer 1203 may be formed as a single layer or a double layer. The graphene layer 1203 may be formed to have a thickness of approximately 0.3 to 2 nm. In addition, a protective layer 1204 is formed on the graphene layer 1203.

The protective layer 1204 is for protecting the graphene layer 1203 in a process to be described later. The protective layer 1204 is formed in a thickness of 200 nm to 10 μm by spin coating any one of polymethyl methacrylate (PMMA), photoresist (PR), ER (electron resist, electronic resist), SiOx, and AlOx. Can be.

Next, on the protective layer 1204, an adhesive layer 1205 is further formed. As the adhesive layer 1205, any one of an adhesive tape, glue, epoxy resin, thermal release tape, and water-soluble tape is formed to a thickness of 100 to 200 µm. The adhesive layer 1205 is for supporting the graphene layer 1203 when physically separating the graphene layer 1203 including the catalyst layer 1202 from the substrate 1201, as described later.

Thereafter, the substrate 1201 is separated from the catalyst layer 1202 and the catalyst layer 1202 is removed. When the substrate 1201 is formed of silicon, the bottom surface of the substrate 1201 is cut with a knife to form a cutting line. Alternatively, the edge portion of the substrate 1201 is removed, and a gap is formed between the catalyst layer 1202 and the substrate 1201.

Next, when the hydrophilic liquid is brought into contact with the cutting line or the gap, the hydrophilic liquid penetrates the cutting line or gap of the substrate 1201 and weakens the adhesion between the substrate 1201 and the catalyst layer 1202, thereby reducing the substrate ( 1201) is easily separated from the catalyst layer 1202. Water, alcohol, and acetone can be used as the hydrophilic liquid.

Next, the adhesive layer 1205 is lifted to separate the substrate 1201 from the catalyst layer 1202. As another method, the substrate 1201 may be directly removed by an ion-milling method. The substrate 1201 may be removed by chemical etching. The etchant depends on the material of the substrate 1201, and KOH, FeCl3, HCl, HF, and reactive ion/etch/etchant are used.

Next, as a method of removing the catalyst layer 1202, wet etching of the catalyst layer 1202 is performed. The catalyst layer 1202 can be removed by putting the substrate 1201 in a mixture of FeCl3, HCl, and water.

As another method, the catalyst layer 1202 may be removed by reactive ion etching, ion milling, or the like.

Next, the resultant is washed. In washing, isophthalic acid (IPA) and deionized (DI) water are used. 11 is a diagram illustrating a method of transferring graphene, and more particularly, a diagram illustrating a step of aligning a resultant on the transfer substrate 1301 so that the graphene contacts the transfer substrate 1301. On the transfer substrate 1301, a contact solution 1302 is applied. As the contact solution 1302, any one of DI water, isopropyl alcohol, ethanol, methanol, and mineral oil is used. Next, while sliding the resultant on the transfer substrate 1301, the resultant is aligned on the transfer substrate 1301.

When the surface of the transfer substrate 1301 has a hydrophobic property with respect to the contact solution 1302, the contact solution 1302 is applied on the graphene layer 1203, and the transfer substrate 1301 is applied on the graphene layer 1203. You can also sort on. Next, the transfer substrate 1301 is aligned with the graphene layer 1203 while sliding the transfer substrate 1301 on the graphene layer 1203.

12 shows a transfer substrate 1301 to which the graphene layer 1203 is transferred. In order to remove the contact solution 1302 from the transfer substrate 1301, the transfer substrate 1301 may be heat-treated at approximately 60° C. for approximately 6 hours to remove the contact solution 1302 and dry.

13 shows a transfer substrate 1301 to which the graphene layer 1203 is transferred. The adhesive layer 1205 and the protective layer 1204 were sequentially removed. The removal of the adhesive layer 1205 and the protective layer 1204 can be performed by a method such as etching, ion milling, or heat treatment, and detailed descriptions are omitted.

Next, in order to remove the chemical residue from the graphene layer 1203, it is washed with IPA, DI water, or the like.

In this way, the graphene layer is formed, but the graphene layer produced by CVD is once formed on the silicon substrate 1201 and then transferred onto the transfer substrate 1301, so the process is complicated.

Here, in the description of the present invention, graphite existing in one layer is a single layer graphene, graphite existing in two to 10 layers is multi-layered graphene, and graphite existing in 11 or more layers is used as graphite particles. When only graphene is described, it represents a state in which single-layer graphene and multi-layer graphene are mixed.

Japanese Patent Publication No. 2011-105590

However, in order to prepare a graphene layer by chemical vapor deposition as described above, there is a problem in that the graphene layer cannot be directly formed on a substrate having no heat resistance because it becomes high temperature during CVD.

An object of the present invention is to provide a method for separating graphene, which is capable of separating graphene without using a substrate or temperature condition to solve the conventional problem.

In order to solve the above problem, the graphene separation method of the present invention applies a magnetic field to a container containing graphite particles, graphene, and a solvent, and by the magnetic field, in the solvent, the graphite particles and the graphene are different from each other. A method for separating graphene comprising a separation process of separating at a location and a extraction process of extracting the solvent and the graphene from a discharge port formed in the container.

According to the graphene separation method of the present invention, graphite having a desired number of layers can be easily obtained.

1 is a schematic diagram of a graphite pulverization system according to an embodiment.
Fig. 2 is an SPM diagram of graphene in which the number of layers is mixed in a method for separating graphene in an embodiment.
3 is a schematic diagram of a dispersion obtained by dispersing graphite powder in ethanol in a method for separating graphene according to an embodiment.
Fig. 4(a) is a schematic plan view in which a dispersion is put into a container in which a magnet is installed around a magnet in the method for separating graphene in an embodiment, (b) is a cross-sectional view of (a), and (c) is ( a) It is a diagram showing the relationship between the force acting at the time.
5 is a schematic diagram showing a state in which a dispersion is applied to a substrate while stirring the dispersion in the method for separating graphene in Example 1. FIG.
6 is an SPM diagram of a substrate after drying ethanol to which a dispersion of the method for separating graphene in Example 1 is applied.
Fig. 7 is a schematic diagram showing a state in which the nozzle shape of Fig. 5 of the method for separating graphene in Example 2 is changed and the dispersion is applied to the substrate while stirring the dispersion.
Fig. 8 is an SPM diagram of a substrate on which ethanol is dried after coating a dispersion of a method for separating graphene in Example 2.
9 is a view showing the difference in distance between the center of the syringe and the center of the nozzle of FIG. 7 and the thickness of the obtained graphene.
10 is a diagram showing a method for forming graphene using the conventional chemical vapor deposition method described in Patent Document 1. FIG.
11 is a diagram showing a transfer method of graphene produced by the conventional manufacturing method described in Patent Document 1. FIG.
12 is a diagram showing a transfer substrate to which graphene is transferred by the conventional forming method described in Patent Document 1;
13 is a diagram showing a transfer substrate to which graphene is transferred by the conventional forming method described in Patent Document 1. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)

Graphite is a material having a layered structure in which carbon atoms are arranged in the shape of a turtle shell having hexagonal carbon atoms, and these layers are overlapped. As graphite having such crystallinity, natural graphite produced as a mineral or graphite with high crystallinity artificially produced by thermally treating CVD or an organic film at a high temperature (crystalline graphite) is common.

<Graphite raw material>

This time, using crystalline graphite obtained by high-temperature heat treatment of the organic film as a raw material, crystalline graphite was pulverized to produce graphene. Even in the case of using natural graphite other than the crystalline graphite used this time or crystalline graphite obtained from CVD, since the binding energy of the carbon atoms is the same, it is considered that the same result can be obtained. Further, crystalline graphite has a larger number of layers than the graphite particles defined above.

1 is a schematic diagram of a graphite pulverization system according to an embodiment. Crystalline graphite as a raw material was put into the raw material supply tank 101 and coarsely pulverized by a cutter mill 102 to produce crystalline graphite powder having a diameter of several mm.

Thereafter, the obtained crystalline graphite powder is supplied to the jet mill 103, and the crystalline graphite is finely formed by a jet stream generated in the pulverization zone 104 with 0.58 MPa high-pressure air supplied from the air hose 105. Crushed.

As for the pulverized crystalline graphite powder, only fine and light crystalline graphite powder flies to the upper part of the jet mill 103 by airflow generated in the jet mill 103, and a classifier that rotates at high speed at 20000 RPM. Only the powder passing through (106) was collected in the recovery tank (107).

In addition, a filter 109 was provided in the air exhaust duct 108, and fine crystalline graphite powder contained in the exhausted air was also recovered by the filter 109. The particle diameter of the recovered crystalline graphite powder was measured with a particle size distribution meter (Microtrac MT3300EX2, manufactured by Nikiso Co., Ltd.), and it was confirmed that the particles were several hundred µm to several tens of µm.

Next, it was verified whether the powder produced by the above method contained single-layer graphene and multi-layer graphene.

The powder obtained by the above method was dispersed in ethanol, coated on the silicon wafer 200, dried with ethanol, and analyzed on the silicon wafer 200 with a scanning microscope (SPM). As a result of the analysis, it was confirmed the presence of single-layer graphene 201 having a thickness of 0.3 nm, multi-layer graphene 202 having a thickness of 10.4 nm, and graphite particles 203 having a thickness of 560 nm. The size of the long side in each plane direction ranged from several µm to several tens of µm.

It can be seen that by pulverizing with a jet mill, the layers of graphite are peeled off, so that it is possible to manufacture a single layer graphene 201 and a multilayer graphene 202. However, only by pulverizing the crystalline graphite by a jet mill, the single-layered graphene 201, the multi-layered graphene 202 and the graphite particles 203 are mixed. For this reason, it is necessary to separate the single-layered graphene 201 and the multi-layered graphene 202 from the graphite particles 203.

3 shows a schematic diagram of a dispersion 303 in which graphite powder produced by the jet mill shown in FIG. 1 is dispersed in ethanol 302 as a solvent.

The dispersion 303 weighs 1 mg of a powder including single-layer graphene 201, multi-layer graphene 202 and graphite particles 203, which can be confirmed to be obtained by pulverizing the crystalline graphite by a jet mill. Then, after pouring into the water tank 301 having a capacity of 13.5 ml and an inner diameter of φ 20 mm, 10 ml of ethanol 302 was put, and ultrasonic dispersion was performed for 5 minutes under conditions of 100 W and 28 kHz to prepare an ethanol dispersion.

<How to separate>

Next, this dispersion 303 is put in a syringe 401 (container), and a method of separating graphene and ethanol 302 using the graphene separation apparatus of the present invention will be described. 4(a) shows a schematic plan view in which a magnetic field source is disposed around a syringe 401. As shown in FIG. Fig. 4(b) is a sectional view a-b in Fig. 4(a). The graphene separating apparatus of the present invention includes a syringe 401, an N-pole magnet 402 and an S-pole magnet 403 as magnetic field sources, and a stirring rod 404 (stirring portion). A nozzle 405 (discharge port) having an inner diameter of 1 mm is attached to a syringe 401 having an inner diameter of 50 mm and a height of 100 mm.

Around the syringe 401, a rectangular parallelepiped having a length of 40 mm, a width of 40 mm, and a height of 100 mm, and a 1-Tesla N-pole magnet 402 is provided toward the syringe 401 side. Moreover, the S-pole magnet 403 of the same size and the same magnetic flux density is provided toward the syringe 401 side. The N-pole magnet 402 and the S-pole magnet 403 are provided to face each other with the syringe 401 as the center. A stirring rod 404 is installed in the center of the syringe 401.

The magnetic flux density of the N-pole magnet 402 and the S-pole magnet 403 needs to be at least 0.05 Tesla or more. If it is smaller than this, the single layer graphene 201 and the multilayer graphene 202 cannot be separated from the graphite particles 203. If it is more than 5 Tesla, it is too strong, and the single-layered graphene 201, the multi-layered graphene 202, and the graphite particles 203 are aggregated and cannot be separated. Therefore, a magnetic flux density of 0.05 Tesla or more and less than 5 Tesla is required. Preferably, if it is 0.5 Tesla or more and 3 Tesla or less, it is good in terms of time and precision.

In the single-layered graphene 201, the multi-layered graphene 202, and the graphite 203, the magnetization rate of diamagnetic generated varies according to the difference in the number of these layers. As a result, according to the difference in the number of layers of graphene, the distribution position may be different.

The stirring rod 404 is attached to a tip of a rod having a diameter of 1 mm and a triangular weight having a diameter of 10 mm and a height of 15 mm. This stirring rod 404 was inserted 90 mm from the top of the syringe 401 and rotated. As a result, the dispersion 303 is agitated, and a centrifugal force is applied to the single layer graphene 201, the multilayer graphene 202, and the graphite particles 203.

At the same time, since a magnetic field is generated from the N-pole magnet 402 toward the S-pole magnet 403, among the dispersion 303 rotating in the syringe 401, the single-layered graphene 201 having a thickness of one layer is Since the diamagnetic per unit weight is the strongest, it tries to separate from the N-pole magnet 402 and the S-pole magnet 403, and tries to gather on the center line. The smaller the number of layers, the stronger the diamagnetic force.

This relationship will be described in Fig. 4(c). Fig. 4(c) is a schematic plan view similarly to Fig. 4(a). The directions of the centrifugal force 601 and the diamagnetic force 602 are shown. It can be separated by the magnitude relationship between the centrifugal force (Equation 1) and the diamagnetic force (Equation 2).

Centrifugal force = m×g×r… (Equation 1)

… (식 2)

… (Equation 2)

Where m is the mass of graphene, g is the gravity, V is the volume, μ0 is the magnetic permeability in vacuum, ΔB/Δz is the magnetic field change in the radial direction, B is the magnetic field, χ is the susceptibility, and r is from the center in the horizontal plane. Is the distance.

With respect to the diamagnetic force 602, the single-layer graphene 201, the multi-layer graphene 202, and the graphite particles 203 are materials made of only carbon, and thus have the same density. However, the susceptibility varies greatly depending on the number of layers, and the single layer is the strongest. Regarding the centrifugal force, it is the same density, and the centrifugal force is determined by the position at radius r.

As a result, if the centrifugal force 601 is appropriately adjusted according to the force (number of rotations) to rotate the stirring rod 404, the single-layered graphene 201 having a strong diamagnetic force 602 is collected in the center, and In the middle part, around the multi-layered graphene 202, graphite particles 203 are distributed (dispersed).

On the other hand, by the centrifugal force caused by rotation by the stirring rod 404, the whole is agitated, the multilayer graphene 202 and the graphite particles 203 are collected on the outer periphery, and the single layer graphene 201 is attracted to the center. Lose.

As a result, single-layered graphene 201 is collected in the center. From the nozzle 405, a single-layer graphene 201 having strong diamagnetic is applied. Accordingly, the graphene 201 can be separated. The size of the nozzle 405 may be installed within a range where the single-layer graphene 201 gathers.

On the other hand, when the centrifugal force (number of rotations) is controlled, not only the single layer graphene 201 but also the multilayer graphene 202 is collected in the center and separated from the graphite particles 203, the single layer graphene 201, the multilayer A mixture of graphene 202 may be applied. Accordingly, the single-layer graphene 201 and the multi-layer graphene 202 can be separated.

However, centrifugal force is not an essential factor. Since graphene and graphite are distributed according to the magnetic field, the above method is realized only by the magnetic field. By applying a centrifugal force, graphene and graphite are more likely to be distributed more homogeneously. As a result, it is easy to apply and form only the single-layer graphene 201 with good purity. When centrifugal force is not used, the graphene separation apparatus of the present invention does not have to be provided with a stirring rod.

Further, the method may be a method of stirring with a stirring rod 404, applying a centrifugal force before application, and not applying a centrifugal force during application (not stirring).

In addition, as graphene, graphite, and graphene alone, the method is realized. Even if other particles with weaker diamagnetic properties than graphene are included, the method is realized.

(Example 1)

5 shows a schematic diagram of applying a dispersion to a substrate while stirring the dispersion using the graphene layer forming apparatus of the present invention. The graphene layer forming apparatus of the present invention includes a graphene separation device, a holding unit for holding the substrate 501, and a moving unit for relatively moving the nozzle 405 and the substrate 501.

The rotation speed of the stirring rod 404 is set to 100 rpm, and after stirring for 5 minutes, the syringe 401 is drawn at a speed of 1 ml/sec and 5 mm/sec while being drawn out from the dispersion and the nozzle 405 on the substrate 501. Moved. Thereafter, ethanol was dried to obtain a substrate 501 coated with graphene.

The discharge method was pressurized by a pressurizing method to apply a solvent. However, when the opening of the nozzle 405 is large, since the solvent is naturally discharged, a shutter is provided in the nozzle 405 to control on and off. Alternatively, at the time of non-application, it may be set to negative pressure and pressurized at the time of application.

6 shows the SPM image of the substrate after coating the dispersion and drying ethanol. In FIG. 6, a dark area indicates the surface of the silicon wafer, and a bright area indicates graphene and graphite.

Table 1 shows the results of analyzing the difference in height at the locations of the lines shown in FIG. 6.

<Table 1>

As a result of analyzing the thickness of the obtained graphene by SPM, it can be seen that the difference in height at a point is 0.3 nm, and that it is a single layer graphene. In addition, it can be seen that the location b is a multilayer graphene having a height difference of 1.7 nm and 5 layers of graphene, and the location c is a multilayer graphene having a height difference of 3.3 nm and 9 layers. As a result, centrifugal force was applied in the magnetic field, and the heavy graphite particles 203 were collected on the outer periphery of the syringe 401. It became possible to separate the single-layered graphene 201 and the multi-layered graphene 202, which are light in weight and thin in thickness, from the graphite particles 203.

In addition, the single-layer graphene 201 may be separated and applied to the substrate with a separate device.

(Example 2)

Fig. 7 shows a schematic diagram in which the shape of the nozzle 406 in Fig. 5 is changed and a dispersion is applied to a substrate while stirring the dispersion.

In the portion connected from the syringe 401 to the hole of the nozzle 406, a protrusion with a taper in the reverse direction is provided. The protrusion protrudes upward, and a taper is provided from the protrusion toward the periphery downward of the container. The tapered portion was formed into a shape having a height of 10 mm with an angle of 45 degrees in the direction from the nozzle 406 toward the outer peripheral portion. If there is a projection, it is preferable, and a tapered shape is more preferable.

In the syringe 401 to which the nozzle 406 is attached, a single layer graphene 201, a multilayer graphene 202, and a dispersion 303 of the graphite particles 203 are mixed with ethanol 302, Ultrasonic dispersion for 5 minutes was performed under conditions of 100 W and 28 kHz, and a dispersion 303 in which the aggregated graphene was dispersed was placed.

Using the nozzle 406 of this shape, the rotational speed of the stirring rod 404 is set to 100 rpm, and after stirring for 5 minutes, the syringe 401 is moved at a speed of 5 mm/sec while discharging the liquid at 1 ml/sec. Made it. Then, ethanol 302 was dried to obtain a substrate 501 coated with a single layer graphene 201.

Fig. 8 shows an SPM image of a substrate on which ethanol is dried after applying the dispersion 303. Under this condition, it can be confirmed that several microns of graphene are scattered.

Table 2 shows the results of the analysis of the height at the analysis points d, e, and f of the line shown in FIG. 8.

<Table 2>

As a result of analyzing the obtained graphene thickness by SPM, the height difference of the analysis site e was 0.3 nm, the analysis site f had a height difference of 0.3 nm, and the analysis site g had a height difference of 0.4 nm, so a single layer graphene was applied to the substrate. Can be seen.

As a result, although the single-layered graphene 201 and the multi-layered graphene 202 were mixed in the dispersion 303 applied in Example 1, only the single-layered graphene 201 could be separated again.

In the nozzle 406, by making the shape of the location in contact with the dispersion 303 into a shape having a height of 10 mm having an angle of 45 degrees toward the outer peripheral portion, it has become possible to separate and apply only the single layer graphene 201. By providing a taper, anything other than the single-layered graphene 201 wound up by mistake disappears.

<About the center of the syringe and the center of the nozzle>

The distribution of each particle in the dispersion 303 in the syringe 401 is shown next. In the configuration of Fig. 7, the position of the nozzle 406 is changed to the syringe 401, the dispersion 303 is applied, and each particle is irradiated from the application result.

9 shows the distance from the center of the syringe 401 to the center of the nozzle 406 and the thickness of graphene obtained by application in the configuration of FIG. 7. In Fig. 9, when the center of the syringe 401 and the center of the nozzle 406 coincide, the horizontal axis becomes 0 mm. Fig. 9 shows the results of analyzing the coating material by changing the position of the nozzle.

The vertical axis is the film thickness of graphene after application at the position of the nozzle 406. It measured 100 points each, and made the thickness which shows the largest ratio as the vertical axis of a plot.

By shifting the center of the nozzle from the center of the syringe, the centrifugal force due to stirring and the diamagnetic balance of the magnetic field are changed. When the center of the syringe and the center of the nozzle are aligned, 100 places of 0.3nm single-layer graphene are measured, and 82 places of single-layer graphene are obtained, whereas when shifted by 1mm, 100 places of 0.7nm multilayer graphene are measured. When the location is shifted by 3 mm, 100 locations of 1.6 nm multi-layered graphene are measured, 72 locations, and when shifted by 5 mm, 100 locations of 2.4 nm multi-layered graphene are measured, and it becomes possible to obtain at a ratio of 68 locations.

From this result, it is possible to separate each number of graphene layers and apply them to a substrate according to changes in centrifugal force and diamagnetic properties due to the difference in the number of layers of graphene in the magnetic field. In addition, by installing the nozzle 405 in the location where the graphite according to the number of layers is located, it can be taken out. Further, a layer may be formed by applying the taken out liquid.

Regarding the relationship between the magnetic flux density and the stirring speed, when the magnetic flux density becomes weak, the magnetic flux density applied to graphene decreases exponentially. For this reason, since the antimagnetic force generated by graphene is also small and separated, it is necessary to decrease the stirring speed and lengthen the stirring time.

<modification example>

Further, in the above example, the centrifugal force by the stirring rod 404 was used, but the centrifugal force is not essential. Each particle can be distributed only by magnetic force, and coating is also possible.

Since there is a centrifugal force, particles can be separated more precisely. Further, prior to application, the solvent is stirred with the stirring rod 404 to disperse the particles in the solvent, and at the time of applying the solvent, the stirring rod 404 may be stopped and applied.

You may stir before application of the solvent, and stop stirring during application.

<As a whole>

In addition, the single-layer graphene 201, the multiple-layer graphene 202, and the graphite particles 203 have been described with respect to separation and application, but the same can be carried out in the case of separation of graphene and graphite. The single-layered graphene 201 and the multi-layered graphene 202 may be used as graphene and may be separated from graphite.

In addition, since it contains a material different from graphene, graphene can be separated. In addition, a graphene layer may be formed from the separated graphene. Graphene, among substances, has a large diamagnetic force and can be separated. In addition, even in the case of only graphene and a solvent, a graphene layer may be formed by applying a solvent containing a large amount of graphene by the above method.

The method of forming a graphene layer of the present invention has a characteristic that single-layer graphene and multi-layer graphene can be classified, and graphene having a desired number of layers can be easily formed on a substrate, and semiconductor devices such as electronic devices and nanotechnology materials It can also be applied to the use of transparent electrodes.

101: raw material supply tank 102: cutter mill
103: jet mill 104: grinding zone
105: air hose 106: classifier
107: recovery tank 108: exhaust duct
109: filter 200: silicon wafer
201: single layer graphene 202: multilayer graphene
203: graphite particles 301: water tank
302: ethanol (solvent) 303: dispersion
401: syringe (container) 402: N-pole magnet
403: S pole magnet 404: stirring rod (stirring portion)
405: nozzle (discharge port) 406: nozzle (discharge port)
501: substrate 601: centrifugal force
602: diamagnetic force 1201: substrate
1202: catalyst layer 1203: graphene layer
1204: protective layer 1205: adhesive layer
1301: transfer substrate 1302: contact solution
H: diamagnetic force a to g: analysis site
r: radius

Claims (14)

Separation in which a magnetic field is applied to a container containing graphene particles having 11 or more layers and graphene and a solvent having 10 or less layers, and separates the graphite particles and the graphene at different positions in the solvent by the magnetic field Process,
Graphene separation method comprising a takeout step of taking out the solvent and the graphene from the discharge port formed in the container. The method according to claim 1,
A magnetic field source is disposed around the container, and the discharge port is formed in the lower center of the container. The method according to claim 1,
A graphene separation method in which a protrusion protruding upward is disposed around the inside of the container of the discharge port. The method according to claim 1,
Graphene separation method further comprising a stirring process for stirring the solvent. The method of claim 4,
In the separation process, by stirring the solvent and acting on the graphite particles and the graphene, separating the graphite particles from the graphene by the action of a centrifugal force by the stirring and a diamagnetic force by the magnetic field, How to separate graphene. The method according to claim 1,
In the extraction process, while stirring the solvent, the graphene and the solvent are taken out. The method according to claim 1,
The graphite particles and the graphene are graphene powder in which at least one of natural graphite, graphite produced by chemical vapor deposition, and graphite produced by thermally treating an organic film at a high temperature is pulverized graphene powder. The method of claim 7,
The pulverized graphite powder is fractionally distilled in an air stream to obtain the graphene and the graphite particles. delete A method of forming a graphene layer, having a coating process of applying the graphene taken out in the extraction process according to any one of claims 1 to 8 to a substrate. A container for placing graphene with 10 or less layers and graphite particles with 11 or more layers and a solvent;
Having a magnetic field source located around the container,
The container, a graphene separation device having a discharge port disposed under the container. The method of claim 11,
In the container, the graphene separation device further has a stirring portion for diffusing the graphene and the graphite particles and the solvent. The method of claim 11,
A graphene separating device in which a protrusion protruding upward is installed around the inside of the container of the discharge port. The graphene separation device according to any one of claims 11 to 13, and
A holding part for holding the substrate,
The graphene layer forming apparatus having a container of the graphene separation device and a moving part for relatively moving the holding part.

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