KR101984696B1 - The nano wire-graphene structure and the method of manufacturing the nano wire-graphene structure - Google Patents

Abstract

A method of manufacturing a nanowire-graphene structure and an apparatus including the same are provided. A method of manufacturing a nanowire-graphene structure includes growing a graphene layer on a substrate, growing a plurality of nanowires on the graphene layer, and separating the graphene layer and the substrate, And is formed of a material that is not covalently bonded to the graphene layer.

Description

TECHNICAL FIELD The present invention relates to a nanowire-graphene structure, a device including the nanowire-graphene structure, and a method of manufacturing the nanowire-graphene structure.

This disclosure relates to nanowire-graphene structures, devices that include nanowire-graphene structures, and methods of making nanowire-graphene structures.

Graphene is a material with a two-dimensional hexagonal carbon structure that is thinner than just a single layer of atoms and conducts electricity 100 times faster than monocrystalline silicon, . Graphene is a zero-gap semiconductor, and has attracted attention as a basic material for electronic circuits, such as replacing existing semiconductor materials.

In addition, nanowires are one-dimensional nanostructures that have a wide surface area and thus have good reactivity and flexibility. The shape of the nanowire is most commonly VLS (Vapor-Liquid-Solid) method using a catalyst such as a transition metal, and the diameter is controlled by a catalyst or a pattern. The growth direction can also be controlled by using the surface index of the semiconductor substrate. Although research on the characteristics of each of the nanowires and device fabrication have been reported a lot, application of the nanowires grown on the substrate as they are as devices has been difficult due to the uniformity, perpendicularity, stability of the nanowires, There have been difficulties.

Therefore, in the conventional technology for elementizing nanowires, the nanowires grown on the substrate are horizontally arranged on the desired substrate by using a method of dispersing or sliding the nanowires on the substrate, As it is.

The present disclosure provides a nanowire-graphene structure in which nanowires are grown on a graphene.

The present disclosure provides a method of making a nanowire-graphene structure.

A method of fabricating a nanowire-graphene structure according to one type of the present invention includes growing a graphene layer on a substrate; Growing a plurality of nanowires on the graphene layer; And separating the graphene layer and the substrate, wherein the substrate is formed of a material that is not covalently bonded to the graphene layer.

The plurality of nanowires may be grown perpendicularly to the graphene layer.

In addition, the plurality of nanowires may not be interconnected.

The substrate may include at least one of a semiconductor, quartz, glass, and sapphire.

In addition, the nanowire may be formed of at least one material selected from the group IV semiconductor material, the compound semiconductor material, the oxide, and the nitride.

And depositing a growth layer on the substrate before depositing the graphene layer on the substrate.

Also, the growth layer may be formed of germanium.

The step of separating the graphene layer from the substrate can dissolve the germanium in water and separate the graphene layer from the substrate.

Also, the growth layer may be formed of a metal material.

The step of separating the graphene layer from the substrate may include separating the growth layer from the substrate by applying a voltage to the metal material.

The method may further include the step of removing the growth layer formed on the graphene layer using a wet etching method.

The plurality of nanowires may be grown using an electrochemical deposition method.

The disclosed nanowire-graphene structure does not require a separate substrate, so it is easy to elementize the nanowire-graphene structure.

Since the nanowire-graphene structure can be turned into an element, electronic devices and optical devices having a large area can be manufactured.

1 is a cross-sectional view illustrating a nanowire-graphene structure according to an embodiment of the present invention.
FIGS. 2 through 5 are diagrams illustrating a method of fabricating a nanowire-graphene structure according to an embodiment of the present invention.
6 is a scanning electron micrograph of the nanowire-graphene structure detached from the substrate.
7 is a scanning electron micrograph of a nanowire-graphene structure detached from a substrate.

The disclosed nanowire-graphene structures will now be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view illustrating a nanowire-graphene structure according to an embodiment of the present invention.

As shown in FIG. 1, a nanowire-graphene structure has a plurality of nanowires 20 vertically arranged on a graphene layer 10.

Here, graphene refers to a polycyclic aromatic molecule in which a plurality of carbon atoms are covalently bonded to each other to form a two-dimensional thin film of a carbon hexagonal surface of a two-dimensional structure, that is, a honeycomb structure. A 6-membered ring is formed as a repeating unit, but it is also possible to further include a 5-membered ring and / or a 7-membered ring. Thus, the graphene appears as a single layer of sp2 hybridization to each other. The graphene may have various structures, and such a structure may vary depending on the content of the 5-membered ring and / or the 7-membered ring which may be contained in the graphene. The graphene may be composed of a single atomic layer, but it is also possible to form a plurality of atomic layers by laminating them to each other. Such graphene is transparent, chemically stable, and has excellent electrical conductivity. Particularly, since the elasticity is good, it does not lose the electric conductivity even when stretched or folded.

On the other hand, the plurality of nanowires 20 are vertically arranged on the graphene layer 10 and are not coupled to each other. The nanowire 20 is a very fine wire having a diameter of several nanometers in cross section, and the nanowire 20 is formed of at least one material selected from a quaternary semiconductor material, a compound semiconductor material, a metal oxide, and a gallium nitride .

Such a nanowire-graphene structure can be applied to various devices because it can be deformed in various forms. Or by transferring the nanowire-graphene structure to a desired substrate. For example, a nanowire-graphene structure can be used as a charge-conducting layer, a photoactive layer that induces a mutual conversion of light energy and electrical energy, and a piezoelectric layer that produces piezoelectric energy. Thus, the nanowire-graphene structure can be applied not only to energy fields such as electronic devices, optical devices, thermoelectric devices, piezoelectric devices, and photovoltaic devices, but also capacitors and sensors.

FIGS. 2 through 5 are diagrams illustrating a method of fabricating a nanowire-graphene structure according to an embodiment of the present invention.

Referring to FIG. 2, a growth layer 40 is first formed on a substrate 30. The substrate 30 may be formed of a material that is not covalently bonded to the graphene. For example, the substrate 30 may be any one of a semiconductor substrate, a quartz substrate, a glass substrate, and a sapphire substrate. The growth layer 40 may be formed by depositing a predetermined material on the substrate 30 in the form of a thin film. The growth layer 40 may be formed of, for example, metal or germanium (Ge) or the like, as a layer on which graphenes to be described later are grown. The metal may include a transition metal such as nickel (Ni), platinum (Pt), ruthenium (Ru), cobalt (Co), iridium (Ir), copper (Cu) On the other hand, when the growth layer 40 is made of germanium (Ge), it is possible to grow graphene without contamination and having a uniform thickness.

Then, as shown in FIG. 3, the graphene layer 10 is grown on the growth layer 40. The growth of the graphene 140 may be performed by chemical vapor deposition (CVD). When the growth layer 40 is germanium, the carbon-containing gas is supplied into the reactor in which the substrate 30 is disposed. As the carbon-containing gas, CH4, C2H2, C2H4, CO and the like can be used. The graphene layer 10 is then grown on the growth layer 40. The growth of the graphene layer 10 takes about 10 minutes to 60 minutes at about 200-1100 DEG C, with a total pressure in the chamber of 0.1-760 torr. When the growth layer 40 is a metal, a carbon-containing gas is supplied to the substrate 30 on which the growth layer 40 is formed and heated so that carbon is absorbed by the metal. Next, rapid cooling is performed to grow graphene by crystallizing carbon from the metal.

Then, as shown in FIG. 4, a plurality of nanowires 20 are vertically grown on the graphene layer 10. The nanowire 20 is grown using an electrochemical deposition method while supplying a solution containing a precursor for growth of the nanowire 20. The precursor may vary depending on the material of the nanowire 20 to be grown. For example, if a nanowire 20 of nitride material is to be grown, a nitrogen precursor may be used. In addition, a nitrogen precursor such as ammonia gas is supplied. The method of growing the nanowires 20 may vary depending on the material of the nanowires 20. For example, when the nanowire 20 is sodium vanadate, a solution containing sodium and vanadium is applied to the graphene, a first heat treatment is performed to form a precursor, and then a second heat treatment is performed to grow the nanowire 20 . 6 is a scanning electron micrograph of the nanowire 20 vertically grown on a graphene layer on a semiconductor substrate.

Finally, as shown in Fig. 5, the graphene layer 10 on which the nanowires 20 are grown is separated from the substrate 30. After the nanowires 20 are grown in the graphene layer 10, the nanowires 20 serve as adherent materials attached to the graphene layer 10, allowing the graphene layer 10 to be easily detached from the substrate 30 . For example, when germanium is used as the growth layer 40, germanium is easily dissolved in a solution such as water, so that the graphene layer 10 is immersed in the water by immersing the graphene 10 in which the nanowires 20 are grown, ). ≪ / RTI >

Or a metal layer is used for the growth layer 40, a substrate 30 on which the graphene layer 10 is grown is placed in a water tank filled with an electrolyte, and a voltage is applied to the metal. Then, bubbles are generated between the metal and the substrate 30 due to the chemical reaction, and the metal layer is separated from the substrate 30. Then, the removal of the metal layer may be performed by a wet etching method, and the dissolution liquid may be different depending on the material of the metal layer. This completes the nanowire-graphene structure. 7 is a scanning electron micrograph of a nanowire-graphene structure detached from a substrate.

Such a nanowire-graphene is excellent in elasticity and thermal conductivity, and can be applied not only to energy fields such as electronic devices, optical devices, thermoelectric devices, piezoelectric devices, and photovoltaic devices, but also capacitors and sensors.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

10: graphene layer
20: nanowire
30: substrate
40: Growth layer

Claims (14)

Depositing a metal material on the substrate;
Growing a graphene layer on the substrate using the metal material;
Growing a plurality of nanowires on the graphene layer;
Applying a voltage to the metal material to separate the metal material from the substrate to separate the graphene layer and the substrate; And
And removing the metal material formed on the graphene layer using a wet etching method,
Wherein the substrate is formed of a material that is not covalently bonded to the graphene layer. The method according to claim 1,
Wherein the plurality of nanowires are grown perpendicular to the graphene layer. The method according to claim 1,
Wherein the plurality of nanowires are not interconnected. The method according to claim 1,
Wherein the substrate comprises at least one material selected from the group consisting of semiconductor, quartz, glass, and sapphire. The method according to claim 1,
The nanowire may be a nanowire,
Wherein the nanowire-graphene structure is formed of at least one material selected from the group consisting of quaternary semiconductor materials, compound semiconductor materials, oxides, and nitrides. delete delete delete delete delete delete The method according to claim 1,
Wherein the plurality of nanowires are grown using an electrochemical deposition process. A nanowire-graphene structure produced by the manufacturing method according to any one of claims 1 to 5 and 12. An electronic device comprising a nanowire-graphene structure according to claim 13.

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