KR101532841B1

KR101532841B1 - Graphene structure, piezoelectric energy generator using graphene structure, and method of fabricating the same

Info

Publication number: KR101532841B1
Application number: KR1020130124018A
Authority: KR
Inventors: 김상우; 김성균; 이근영; 이강혁
Original assignee: 성균관대학교산학협력단
Priority date: 2013-10-17
Filing date: 2013-10-17
Publication date: 2015-06-30
Also published as: KR20150044676A

Abstract

The present invention relates to a graphene structure in which a monomolecular material is doped with a gas to a graphene structure, and an energy generating device using the graphene structure and a manufacturing method thereof.
A method of fabricating an energy generating device according to an embodiment of the present invention includes: growing a mono-layer graphene structure by CVD; Transferring the grown graphene structure onto a substrate; Doping a monomolecular material on a graphene structure transferred onto the substrate, wherein bonding occurs between the carbon atom of the graphene and the monomolecular material by doping; And depositing an electrode material on both ends of the graphene structure.

Description

TECHNICAL FIELD The present invention relates to a graphene structure, a piezoelectric energy generating device using the same, and a method of manufacturing the same. BACKGROUND ART [0002]

The present invention relates to a graphene structure in which a monomolecular material is doped with a gas to a graphene structure, and an energy generating device using the graphene structure and a manufacturing method thereof.

As the marketability of energy has expanded in the field of research and increasingly, interest in new material materials has been growing.

We have proposed a new research direction of graphene, a two-dimensional material that is currently being studied, and a complex study with two research objectives: industrialization of conventional piezoelectric energy power plants, and alternatives to overcome limitations that are difficult to commercialize The study on the development of new energy - generating device materials with improved characteristics and efficiency over ceramic and piezoelectric semiconductors has been carried out.

In the case of an energy plant using a conventional piezoelectric material, it is divided into a piezoelectric ceramic and a piezoelectric semiconductor. Piezoelectric ceramics have a disadvantage in that they have a high output voltage but are fragile and difficult to deform and have a low current value and thus can be used in commercial applications. Piezoelectric semiconductors use ZnO-based nanostructures to improve the current value, However, there is a disadvantage in that it is difficult to manufacture a stable and uniformly large-sized device.

On the other hand, graphen's research field is focused on the application as a new channel layer in semiconductors.

As the development of electronic devices is rapidly accelerating, there is an increasing demand in the market. To meet this requirement, a new piezoelectric energy generation device, which is more flexible than conventional piezoelectric devices which can be driven by a flexible, thin, reliable, It is in urgent need of development.

The graphene structure according to an embodiment of the present invention is formed by bonding a mono-layer graphene structure obtained by a CVD method to a carbon atom and a monomolecular material of a graphene structure through gas doping of a mono-layer material . In this case, the monovalent material is characterized by being at least one of H, Li, K, and F.

On the other hand, such a mono-layer graphene structure is transferred onto one surface of the substrate, and electrode materials are deposited on both ends of the graphene structure to obtain a piezoelectric energy generation device. The substrate to be used at this time is preferably flexible.

A method of fabricating an energy generating device according to an embodiment of the present invention includes: growing a mono-layer graphene structure by CVD; Transferring the grown graphene structure onto a substrate; Doping a monomolecular material on a graphene structure transferred onto the substrate, wherein bonding occurs between the carbon atom of the graphene and the monomolecular material by doping; And depositing an electrode material on both ends of the graphene structure.

The substrate is preferably a flexible substrate, and is preferably any one of PEN, PET, and PES.

The step of doping a monomolecular material on a transferred graphene structure on a substrate comprises doping the monomolecular material into a gas atmosphere in a vacuum furnace, wherein the monomolecular material is selected from the group consisting of H, Li, K, and F It is preferable that at least one is.

In the step of depositing the electrode material on both ends of the graphene structure, the electrode material is deposited using FIB (Focused Ion Beam), and the electrode material is preferably Au or Ag.

1 is a schematic view of a graphene structure according to an embodiment of the present invention.
2 is a schematic diagram of an energy generating device manufactured according to an embodiment of the present invention.
3 illustrates a method of fabricating an energy generating device according to an embodiment of the present invention.
Various embodiments are now described with reference to the drawings, wherein like reference numerals are used throughout the drawings to refer to like elements. For purposes of explanation, various descriptions are set forth herein to provide an understanding of the present invention. It is evident, however, that such embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing the embodiments.

The following description provides a simplified description of one or more embodiments in order to provide a basic understanding of embodiments of the invention. This section is not a comprehensive overview of all possible embodiments and is not intended to identify key elements or to cover the scope of all embodiments of all elements. Its sole purpose is to present the concept of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.

1 is a schematic view of a graphene structure according to an embodiment of the present invention.

As shown in FIG. 1, it can be seen that the graphene structure according to an embodiment of the present invention has a bond between carbon atoms and mono-material of the graphene structure.

Generally, graphene is a honeycomb structure in which carbon atoms form a regular hexagon. However, in order to derive the piezoelectric characteristics of the graphene structure, the inventor of the present invention obtained a piezoelectric property by doping a monomolecular material and changing a complete symmetric structure to an asymmetric structure by bonding between a carbon atom and a monomolecular material.

On the other hand, in order to bond between the carbon atoms of the graphene structure and the monovalent material, the graphene must be obtained by the CVD method because graphene must be obtained by the CVD method so that the bonding force between the carbon atoms is not very strong, It is because. Therefore, in the case of graphene produced by various other known methods other than the CVD method, the bonding force between carbon atoms is very strong, and doping is difficult to be performed. Therefore, the graphene structure of the present invention must always be graphened by a CVD method, and the method of forming a graphene by a CVD method has already been disclosed in a number of patents or papers.

On the other hand, it is preferable that the monovalent material is at least one of H, Li, K, and F.

As shown in FIG. 1, a graphene structure doped with a monomolecular material is used as an energy generating element. For this purpose, a graphen structure is transferred to a substrate and electrodes are formed on the graphen structure.

FIG. 3 shows a method of manufacturing an energy generating element according to an embodiment of the present invention, and FIG. 2 shows a schematic view of an energy generating element manufactured according to this method.

As shown in FIG. 3, a method of fabricating an energy generating device according to an embodiment of the present invention includes: growing (S 310) a mono layer graphene structure by CVD; Transferring the grown graphene structure onto the substrate (S 320); Doping (S 330) mono-substance on the transferred graphene structure on the substrate; And depositing electrode material on both ends of the graphene structure (S 340).

The step of growing the mono-layer graphene structure by the CVD method (S 310) is a method of growing the graphene structure by a CVD method since doping of a monomolecular material is possible only in the case of a graphene structure grown by the CVD method . For example, a thermal CVD (Chemical Vapor Deposition) method can be used by a CVD method.

At this time, gas doping or liquid doping may be used for the doping, but it is preferable that the gas doping is performed in the present invention. In the present invention, graphene is modified to have n-type or p-type semiconductor properties depending on the dopant material. In this case, fine control of the dopant is very important in doping. In the case of liquid doping, since doping is carried out by immersing it in a liquid, it is difficult to finely control doping, so it is preferable to perform gas doping. The dopant material can be made to function as a piezoelectric material layer of the energy generating device by changing the graphene semimetal material to a material having a semiconducting property by gas doping.

Step S 320 is a step of transferring the grown graphene structure onto a substrate, in which case the substrate is preferably made of a flexible material. Because the energy generating element made by the method of the present invention is used as a piezoelectric energy generating element, it is necessary to prevent the element from being broken by an external impact or pressure when receiving an external mechanical force, so that the substrate is made of a flexible material desirable.

Preferably, one of PEN, PET, and PES is used as the flexible substrate.

Step S 330 is a step of doping a monomolecular material onto the transferred graphene structure on the substrate, and this doping causes bonding between the carbon atom of the graphene and the monomolecular material. This combination can be seen in the schematic diagram of FIG.

The step of doping the monomolecular material is performed by doping the monomolecular material into a gas atmosphere in a vacuum furnace, wherein the monomolecular material is preferably H, Li, K, F as described above.

In a vacuum furnace, a mono-material is flowed into the chamber in a gaseous state, and doping is performed by bonding between the carbon atom of the graphene and the monatomic material on the surface. At this time, the sp2 bond of the graphene is broken by the bond, so that the symmetry structure between the carbon atoms is broken, and as shown in FIG. 1, the sp3 bond is formed by the bond between the carbon atom and the doping material. At this time, a thin film of a two-dimensional atomic layer thickness is formed, and the doping concentration of the material is controlled by the flow amount of the gas, so that a two-dimensional piezoelectric energy generating device having a high piezoelectric characteristic can be obtained.

On the other hand, by using graphene in this way, it is possible to fabricate a piezoelectric energy generating device with a thickness of about several nanometers, which is much thinner than conventional piezoelectric materials, by utilizing the flexible, transparent and high electrical conductivity characteristics of graphene.

Finally, in step S 340, electrode materials are deposited on both ends of the graphene structure. At this time, in order to deposit a fine electrode, an electrode material can be deposited at a desired position by using a FIB (Focused Ion Beam) equipment. The electrode material is Au and / or Ag.

The piezoelectric energy generating element of the present invention is not a structure for forming electrodes on the upper and lower portions of a piezoelectric material like a conventional piezoelectric power generating element but deposits electrode materials on both ends of the graphene utilizing the feature of the two- . This can be seen in FIG.

By forming the electrodes at both ends of the two-dimensional graphene structure, the portion directly applying the physical pressure becomes the graphene surface. Since the graphene has the flexible nature as described above, it is not broken easily, It will be able to withstand without it. Therefore, it is possible to solve the disadvantage that the upper and lower electrode structures, like the conventional piezoelectric energy generating element, are broken by external pressure or shock.

2 is a schematic diagram of an energy generating device manufactured according to an embodiment of the present invention.

As shown in FIG. 2, there is a flexible substrate 10 on which a two-dimensional graphene structure 20 is transferred. The graphene structure is bonded to carbon atoms and mono-electron materials of the graphene structure by the doping of the monomolecular material 30, thereby changing the symmetry structure to an asymmetric structure. In addition, the electrodes 40 and 40 'for collecting the electric power generated by the external pressure are located at both ends of the graphene structure, not at the upper and lower ends thereof.

The piezoelectric energy generating device using the monomolecular material-doped graphene structure according to an embodiment of the present invention may cause a dipole moment change due to pressure when an external pressure or impact is applied So that electric power is generated according to the deviation of the dipole moment. The generated power is collected through the electrodes at both ends of the graphene structure, and energy harvesting is performed.

The description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features presented herein.

Claims

A graphene structure in which a carbon atom of a graphene structure and a monomolecular material are bonded to each other through a gas doping of a mono-layer material to a mono layer graphene structure obtained by a CVD method is transferred onto one surface of the substrate, An electrode material is deposited on both ends of a graphene structure.

The method according to claim 1,
Wherein the monovalent material is at least one of H, Li, K,
Piezoelectric energy generating element.

delete

The method according to claim 1,
Characterized in that the substrate is a flexible substrate.
Piezoelectric energy generating element.

Growing a monolayer graphene structure by CVD;
Transferring the grown graphene structure onto a substrate;
Doping a monomolecular material on a graphene structure transferred onto the substrate, wherein bonding occurs between the carbon atom of the graphene and the monomolecular material by doping; And
And depositing an electrode material on both ends of the graphene structure,
Wherein the step of doping a monomolecular material onto the transferred graphene structure on the substrate comprises doping the monomolecular material in a gas atmosphere in a vacuum furnace.
A method of manufacturing a piezoelectric energy generating element.

6. The method of claim 5,
Characterized in that the substrate is a flexible substrate.
A method of manufacturing a piezoelectric energy generating element.

The method according to claim 6,
Wherein the flexible substrate is one of PEN, PET, and PES.
A method of manufacturing a piezoelectric energy generating element.

delete

6. The method of claim 5,
Wherein the monovalent material is at least one of H, Li, K,
A method of manufacturing a piezoelectric energy generating element.

6. The method of claim 5,
Wherein depositing an electrode material on both ends of the graphene structure comprises:
Electrode material is deposited using FIB (Focused Ion Beam)
Wherein the electrode material is Au or Ag.
A method of manufacturing a piezoelectric energy generating element.