KR102516209B1 - Graphene-based sensor for ultrafine thermal-optical information detection, preparation method thereof, and controlling method of bandgap of graphene - Google Patents

Abstract

The present invention relates to a graphene-based sensor for detecting ultrafine thermal-optical information and, more specifically, to a graphene-based sensor for detecting ultrafine thermal-optical information, including functionalized graphene and pyroelectric materials with added semiconductor properties and increased charge concentration, a manufacturing method thereof, and a control method of a graphene band gap. According to the present invention, the graphene-based sensor for detecting ultrafine thermal-optical information that is manufactured using the pyroelectric properties of functionalized graphene and pyroelectric materials by inserting a metal layer between graphene and performing heat treatment and operates at room temperature can not only contribute significantly to various sensor industries that require ultra-miniaturization and ultra-precision but can also provide a very important information value to the future bio industry that requires high-speed response and high sensitivity and to the academic and technical fields of two-dimensional materials.

Description

Graphene-based sensor for ultrafine thermal-optical information detection, preparation method thereof, and controlling method of bandgap of graphene}

The present invention relates to a graphene-based sensor, and more particularly, to a graphene-based sensor for detecting ultrafine thermo-optical information, including graphene functionalized by adding semiconductor characteristics and increasing charge concentration, and a pyroelectric material, It relates to a manufacturing method and a method for controlling a graphene band gap.

With the advent of the 4th industry, sensors play a role in detecting and controlling various situations instead of the five human senses, and detecting the radiation spectrum of objects such as astronomy, medical care, security, pollution monitoring, fire detection, vehicle and motion tracking, and indoor temperature. It is an important skill to detect. In particular, thermal-photon detectors operating at room temperature, such as infrared sensors that do not require cooling, are greatly increasing in importance as they are applied to various fields.

Today, many miniaturized electrical control and device technologies already exist for the direct generation, manipulation and sensing of infrared and THz waves. However, most technologies have a disadvantage in that they cannot be expanded to a wide range of areas where THz photonics can be applied for reasons such as material characteristics.

On the other hand, graphene's excellent opto-electronic properties are being used as a new platform for various optoelectronic device applications such as high-speed photodetectors, transparent electrodes for displays and photovoltaic modules, light modulators, and plasmonics. For the application and implementation of graphene, research to improve the physical properties and functions of graphene materials is being actively conducted all over the world. However, to date, the performance of graphene-based thermo-photodetectors has been shown to have characteristics that are 1/10 lower than those of metal and semiconductor-based bolometers at room temperature due to the thin thickness of the monoatomic layer without a band gap and low charge concentration. It is very low compared to the performance of the reported and currently commercialized detectors.

Therefore, in order to overcome the above limitations, it is highly required to develop functionalized graphene and device processing technology by adding semiconductor characteristics and increasing charge concentration.

Republic of Korea Patent No. 10-2019599

A first problem to be solved by the present invention is to provide a graphene-based sensor for detecting ultrafine thermal-optical information, including graphene functionalized by adding semiconductor characteristics and increasing charge concentration.

A second problem to be solved by the present invention is to provide a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information.

A third problem to be solved by the present invention is to provide a method for controlling a band gap of graphene.

The technical problems of the invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the present invention for solving the first problem is to provide a graphene-based sensor for detecting ultrafine thermal-optical information.

A graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention includes a pyroelectric substrate including a pyroelectric material; and a functionalized graphene layer formed on the pyroelectric substrate, wherein the functionalized graphene layer is prepared by heat-treating a graphene/metal/graphene sandwich structure in which a metal layer is inserted between two single-layer graphene sheets. do.

In addition, a graphene-based sensor for detecting ultrafine thermal-optical information according to another embodiment of the present invention includes a pyroelectric substrate including a pyroelectric material; a functionalized graphene layer formed on a portion of the pyroelectric substrate; a source electrode and a drain electrode formed on the pyroelectric substrate to be adjacent to respective ends of the functionalized graphene layer; a gate insulating layer formed on the functionalized graphene layer and contacting the source electrode and the drain electrode while covering the functionalized graphene layer; and a gate electrode formed on the gate insulating layer, wherein the functionalized graphene layer is prepared by heat-treating a graphene/metal/graphene sandwich structure in which a metal layer is inserted between two single-layer graphene sheets. .

The pyroelectric material is KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ) , PCT((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ It can be.

The functionalized graphene layer may exhibit semiconductor characteristics by generating a band gap by modifying the work function of graphene by heat-treating the graphene/metal/graphene sandwich structure.

In the graphene/metal/graphene sandwich structure, the metal is platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), magnesium (Mg) , It may be selected from the group consisting of silver (Ag) and gold (Au).

The metal layer may have a thickness of 1 nm or more and less than 10 nm.

The heat treatment may be performed at 110 to 1,050 °C depending on the metal constituting the graphene/metal/graphene sandwich structure.

The graphene-based sensor for detecting ultrafine thermal-optical information may further include finger electrodes connecting both ends of the gate electrode.

In addition, another aspect of the present invention for solving the second problem provides a method of manufacturing the graphene-based sensor for detecting ultrafine thermal-optical information.

A method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention includes transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10); Depositing a metal layer on the first single-layer graphene sheet (S20); forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); and converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40).

A method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to another embodiment of the present invention includes transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10); Depositing a metal layer on the first single-layer graphene sheet (S20); forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40); Forming a source electrode and a drain electrode so as to be adjacent to each end of the functionalized graphene layer (S50); Forming a gate insulating layer to contact the source electrode and the drain electrode while covering the functionalized graphene layer (S60); and forming a gate electrode on the gate insulating layer (S70).

The pyroelectric material is KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ) , PCT((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ It can be.

The metal may be selected from the group consisting of platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), silver (Ag), and gold (Au). .

The metal layer may be formed by atomic layer deposition (ALD).

The metal layer may have a thickness of 1 nm or more and less than 10 nm.

The heat treatment may be performed in the range of 110 to 1050 °C depending on the metal constituting the graphene/metal/graphene sandwich structure.

The method may further include forming finger electrodes connecting both ends of the gate electrode on the pyroelectric substrate.

In addition, another aspect of the present invention for solving the third problem provides a method for controlling a band gap of graphene. The method for controlling the bandgap of graphene may include transferring a first single-layer graphene sheet onto a substrate (S10); Depositing a metal layer on the first single-layer graphene sheet (S20); forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); and converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40).

According to the present invention, a graphene-based sensor for detecting ultra-fine thermo-optical information operated at room temperature, manufactured by using functionalized graphene and pyroelectric properties of a pyroelectric material by heat treatment by inserting a metal layer between graphenes, is provided. Through this, it can not only greatly contribute to various sensor industries that require microminiaturization and ultra-precision, but also provide very important information value to the future bio industry and the academic and technical fields of 2D materials that require high-speed response and high sensitivity. .

1 is a schematic diagram of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.
2 is a schematic diagram of a graphene-based sensor for detecting ultrafine thermal-optical information according to another embodiment of the present invention.
3 is a schematic diagram showing semiconductor materials and detection ranges generally used in photoelectric sensors.
4 is a conceptual diagram of natural polarization and spontaneous polarization by external stimuli and dipole moment in a pyroelectric material used in a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.
5 is a schematic diagram illustrating a mechanism for detecting heat/light when a graphene-based sensor for detecting ultrafine heat/optical information according to another embodiment of the present invention is irradiated with heat/light.
6 is a process diagram illustrating a method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.
7 is a process chart showing a method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to another embodiment of the present invention.
8 is a Raman spectroscopy spectrum showing functionalization of graphene before and after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.
9 illustrates G band intensity mapping of graphene after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.
10 is a graph showing light detection intensity according to wavelength before and after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the terms used in this specification are terms used to appropriately express preferred embodiments of the present invention, which may vary according to the intention of a user or operator or customs in the field to which the present invention belongs. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

Like reference numerals in each figure indicate like elements.

Throughout the specification, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

As used herein, the term "graphene" refers to a polycyclic aromatic molecule in which a plurality of carbon atoms are covalently linked to each other, and the covalently linked carbon atoms form a 6-membered ring as a basic repeating unit, It is also possible to further include a 5-membered ring and/or a 7-membered ring. As a result, a single-layer graphene sheet appears as a single layer of carbon atoms covalently bonded to each other (usually sp ² bonds), and may be substantially as thick as a carbon atom. The single-layer graphene sheet generally has a light transmittance of 97 to 98%.

[Graphene-based sensor for detecting ultra-fine thermal-optical information]

One aspect of the present invention provides a graphene-based sensor for detecting ultrafine thermal-optical information.

1 is a schematic diagram of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.

Referring to FIG. 1 , a graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention includes a pyroelectric substrate 10 including a pyroelectric material; and a functionalized graphene layer 20 formed on the pyroelectric substrate. At this time, the functionalized graphene layer is characterized in that it is prepared by heat-treating a graphene/metal/graphene sandwich structure in which a metal layer is inserted between two single-layer graphene sheets.

As shown in FIG. 1 , the graphene is a semi-metallic material having a thickness corresponding to that of a carbon atom layer while forming an arrangement in which carbon atoms are connected in a hexagonal shape by sp ² bonding in a two-dimensional space. As a result of evaluating the characteristics of a single-layer graphene sheet having a single-layer carbon atom layer, it has been reported that such graphene can exhibit very excellent electrical conductivity with an electron mobility of about 50,000 cm 2 /Vs or more. In addition, graphene has the characteristics of structural and chemical stability and excellent thermal conductivity. In addition, it is composed of only carbon, a relatively light element, and it is easy to process one-dimensional or two-dimensional nanopatterns. Due to these electrical, structural, chemical, and economic characteristics, graphene is predicted to be able to replace silicon-based semiconductor technology and transparent electrodes in the future, and in particular, it is expected to be applicable to the field of flexible electronic devices due to its excellent mechanical properties.

However, as will be described later, since graphene itself does not exhibit semiconductor properties, it is required to impart semiconductor functionality to graphene in order to use it as a material for a photoelectric sensor or photoelectric device.

Meanwhile, graphene, which was discovered in 2004 by professors Andre Geim and Konstantin Novoselov of the University of Manchester, UK, has been reported by many researchers as not being able to penetrate any known atoms other than hydrogen atoms. Accordingly, the present inventors have studied to impart semiconductor functionality to graphene. As a result, if an ultra-thin metal layer is confined between two single-layer graphene sheets in a graphene/metal/graphene sandwich structure, the metal element can be released from the graphene. Since it cannot come out, it was confirmed that graphene is doped with a metal element through heat treatment, thereby changing the work function of graphene, and the semiconductor function is given to graphene according to the change in the work function of graphene. Functionalized graphene with a semiconductor function in this way can be usefully used for heat/light detection by serving as a semiconductor layer in a device such as a field emission transistor (FET), which will be described later.

2 is a schematic diagram of a graphene-based sensor for detecting ultrafine thermal-optical information according to another embodiment of the present invention.

Figure 2 is a sensor in the form of an FET device, referring to Figure 2,

A graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention

a pyroelectric substrate 10 containing a pyroelectric material;

a functionalized graphene layer 20 formed on a portion of the pyroelectric substrate;

a source electrode 30 and a drain electrode 40 formed on the pyroelectric substrate to be adjacent to respective ends of the functionalized graphene layer;

a gate insulating layer 50 formed on the functionalized graphene layer and contacting the source electrode and the drain electrode while covering the functionalized graphene layer; and

A gate electrode 60 formed on the gate insulating layer may be included.

3 is a schematic diagram showing semiconductor materials and detection ranges generally used in photoelectric sensors.

As shown in FIG. 3, insulators and semiconductor materials exhibit semiconductor characteristics because their valence band and conductance band are separated to form a band-gap, which is useful for detecting heat/light in sensors and the like. Semiconductor materials are mainly used. Since these semiconductor materials have different band gap sizes depending on the type of material, the detectable wavelength range varies. MoS ₂ and black phosphorus below eV can be detected in visible light. However, the valence band and conduction band of graphene have the shape of two cones. If you observe a cross section cut based on the point where the two cones meet, you will see an X-shape where two straight lines intersect. This intersection is called the Dirac Point. In the case of ideal graphene, the Dirac point is located at the Fermi level, and it is known to have almost metallic properties with zero band-gap energy between the valence band and the conduction band. Since graphene has a very small effective mass of electrons near the Fermi level, the movement speed of electrons in graphene corresponds to about 1/300 of the speed of light. Therefore, when making a graphene-based transistor, it can have an electron mobility that is 10 times greater than that of a silicon-based transistor, and can have a wide range of wavelengths from the visible light region through the infrared region to radio waves. can be detected in the area.

However, as described above, since graphene itself does not exhibit semiconductor characteristics, it has been required to impart semiconductor functionality to graphene by changing the work function of graphene to create a band gap. In a pin/metal/graphene sandwich structure, an ultra-thin metal layer is confined between two single-layer graphene sheets, and graphene is doped with a metal element through heat treatment, thereby changing the work function of graphene. While a band gap is generated according to the change (eg, about 0.4 eV or more, as an example, 0.45 eV to 0.8 eV, specifically 0.6 eV to 0.8 eV), a semiconductor function is imparted to graphene to exhibit semiconductor characteristics.

At this time, the metal used in the graphene/metal/graphene sandwich structure is platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), magnesium ( Mg), may be selected from the group consisting of silver (Ag) and gold (Au), but is not limited thereto. As an example, indium (In) may be used as the metal.

The metal layer is preferably an atomic layer having a thickness of 1 nm or more and less than 10 nm. If the thickness of the metal layer is out of the above range, there is a problem in that the graphene is not sufficiently doped with a different type of metal element during heat treatment, so that the graphene is not sufficiently provided with a semiconductor function.

The heat treatment may be performed in a vacuum state or an atmosphere of hydrogen, nitrogen, oxygen, or the like, and may be performed at 110 to 1,050 ° C. depending on the metal used in the graphene/metal/graphene sandwich structure. As an example, when indium is used as the metal layer, the phase transition temperature of indium, that is, the melting point (mp) is 156.6 ° C. If the heat treatment temperature exceeds the phase transition temperature of metal, graphene is caused by the phase transition of metal Since there is a problem in that defects occur during metal doping, the heat treatment may be performed at 110° C. below the phase transition temperature of metal.

In addition, the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention is characterized in that the functionalized graphene layer 20 described above is formed on the pyroelectric substrate 10 including the pyroelectric material.

In the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, the pyroelectric substrate 10 not only plays a basic role as a substrate supporting the structure of the sensor, but also By amplifying the ultra-fine thermal-optical information detection signal of the functionalized graphene layer, the sensitivity of the ultra-fine thermal-optical information detection signal is increased.

4 is a conceptual diagram of a dipole moment in a pyroelectric material used in a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention and spontaneous polarization by an external stimulus.

In general, when the temperature of a ferroelectric material with permanent electric dipoles is raised, the dipole arrangement is slightly disturbed and the polarization is weakened. phenomenon appears. As shown in (c) and (d) of FIG. 4, when the temperature increases or decreases, the polarization changes to a state of decreasing or increasing, and the charge attached to the surface is difficult to change in response to such a change in polarization quickly. As a result, the balance of surface charge changes. This eventually appears as a voltage/current change, whereby thermo-optical information can be detected.

In the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, an ultra-thin metal layer is formed between two single-layer graphene sheets in a graphene/metal/graphene sandwich structure on a substrate including the pyroelectric material. Since the functionalized graphene layer is a heterojunction by heat treatment and imparted with a semiconductor function, electron-electron scattering of graphene converts one high-energy e-h pair into several low-energy e-h pairs, potentially greatly improving the photodetection efficiency. It can detect the wavelength of ultra-fine light quantity.

The pyroelectric materials include KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ), PCT ((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ It may be selected, but is not limited thereto, and PZT may be used as an example.

5 is a schematic diagram illustrating a mechanism for detecting heat/light when a graphene-based sensor for detecting ultrafine heat/optical information according to another embodiment of the present invention is irradiated with heat/light.

As shown in FIG. 5, the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention includes a semiconductor-functionalized graphene layer by heat-treating a pyroelectric substrate and a graphene/metal/graphene sandwich structure, Even when minute heat or light is incident, electrical properties are revealed by the polarization of the pyroelectric substrate, the semiconductor properties of the functionalized graphene layer, and excellent electrical conductivity, so that it can be used in a wide range of wavelengths from the visible ray region through the infrared region to the radio wave. It is possible to detect ultra-fine wavelengths.

In the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, in the case of a transistor element type, the material of the gate electrode, the source electrode, and the drain electrode is not particularly limited as long as it is a conductive material, and platinum, gold, silver, Nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, antimony tin oxide, indium tin oxide (ITO), fluorine Doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium, beryllium, sodium, magnesium, potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloys, Magnesium, lithium, aluminum, magnesium/copper mixture, magnesium/silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, aluminum/aluminum oxide mixture, lithium/aluminum mixture, etc. are used. By this, a film can be formed to form an electrode.

In one embodiment, as the source electrode and the drain electrode, those formed using a fluid electrode material such as a solution, paste, ink, or dispersion containing the conductive material may be used. As the dispersion containing metal fine particles, for example, a known conductive paste or the like can be used, but a dispersion containing metal fine particles having a particle diameter of 0.5 nm to 50 nm or 1 nm to 10 nm is preferable. Examples of the material of the metal fine particles include platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, mole Libdenum, tungsten, zinc, and the like can be used.

It is preferable to form an electrode using a dispersion obtained by dispersing these metal fine particles in a dispersion medium such as water or any organic solvent using a dispersion stabilizer mainly composed of an organic material. As a method for producing such a dispersion of metal microparticles, physical production methods such as in-gas evaporation, sputtering, and metal vapor synthesis, or chemical production methods for generating metal microparticles by reducing metal ions in a liquid phase such as colloidal and co-precipitation methods, etc. can be cited as an example.

The electrode is molded using these metal fine particle dispersions, the solvent is dried, and the metal fine particles are thermally fused by heating in an appropriate range of 100 ° C to 1,300 ° C, for example 110 ° C to 1,050 ° C, if necessary. to form an electrode pattern having a desired shape.

In addition, as materials for the gate electrode, the source electrode, and the drain electrode, known conductive polymers whose conductivity is improved by doping or the like can be used, such as conductive polyaniline, conductive polypyrrole, and conductive polythiophene (polyethylenedioxythiophene and polystyrene complexes of phononic acid, etc.), complexes of polyethylene dioxythiophene (PEDOT) and polystyrene sulfonic acid, and the like can also be suitably used. These materials can reduce the contact resistance between the source electrode and the drain electrode and the semiconductor-functionalized graphene layer.

In the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, the material of the gate insulating layer is not particularly limited as long as it has electrical insulation and can be formed as a thin film, and metal oxide, metal nitride, Materials such as organic compounds can be used, and for example, an inorganic oxide film having a high dielectric constant can be used.

Examples of the inorganic oxide include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium titanate zirconate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Barium titanate, barium magnesium fluoride, lanthanum oxide, fluorine oxide, magnesium oxide, bismuth oxide, bismuth titanate, niobium oxide, strontium bismuth titanate, strontium bismuth tantalumate, tantalum pentoxide, bismuth tantalum niobate, yttrium trioxide and combinations thereof, and examples thereof include silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide.

Inorganic nitrides such as silicon nitride (Si ₃ N ₄ , Si _x N _y (x, y > 0)) and aluminum nitride can also be suitably used.

Examples of gate insulating layers using organic compounds include polyimide, polyamide, polyester, polyacrylate, photoradical polymerization, photocurable resin of photocationic polymerization, copolymers containing acrylonitrile, and polyvinylphenol. , polyvinyl alcohol, novolac resin, cyanoethyl pullulan, and the like can also be used.

In addition, wax, polyethylene, polychloropyrene, polyethylene terephthalate, polyoxymethylene, polyvinyl chloride, polyvinylidene fluoride, polymethyl methacrylate, polysulfone, polycarbonate, polyimidecyanoethyl pullulan, polyimide (vinylphenol) (PVP), poly(methyl methacrylate) (PMMA), polycarbonate (PC), polystyrene (PS), polyolefin, polyacrylamide, poly(acrylic acid), novolak resin, resol resin, polyimide , It is also possible to use a polymeric material having a high permittivity such as polyxylene, epoxy resin, and pullulan.

The gate insulating layer may be a mixed layer using a plurality of inorganic or organic compound materials as described above, or may be a laminated structure thereof.

Methods for forming the gate insulating layer include dry processes such as vacuum deposition, molecular beam epitaxial growth, ion cluster beam method, low energy ion beam method, ion plating method, CVD method, sputtering method, atmospheric pressure plasma method, spray coating method, spin wet processes such as coating methods, blade coating methods, dip coating methods, casting methods, roll coating methods, coating methods such as bar coating methods, die coating methods, and patterning methods such as printing or ink jet; , depending on the material. In the wet process, there is a method of applying and drying a liquid in which fine particles of inorganic oxide are dispersed in any organic solvent or water using a dispersion aid such as a surfactant as necessary, or a so-called sol-gel method in which a solution of an oxide precursor is applied and dried. can be used

The graphene-based sensor for detecting ultrafine thermal-optical information may further include finger electrodes connecting both ends of the gate electrode.

The finger electrodes are for maximizing the efficiency of the graphene-based sensor for detecting ultrafine thermal-optical information, and the width or spacing of the finger electrodes can be adjusted from several nm to several tens of μm. When the pyroelectric material, which is the substrate material, and the finger-type electrode are connected, the contact area with the substrate increases compared to a single electrode, so when external heat and light information is irradiated to the detection area of the device, electricity according to the mechanism of the pyroelectric material Since the change in the dipole moment is increased, and as a result, the magnitude of the change in current or voltage is also increased, the thermal-optical information sensing efficiency of the device can be maximized.

According to the present invention, a graphene-based sensor for detecting ultra-fine thermo-optical information operated at room temperature, which is manufactured by using the pyroelectric properties of functionalized graphene and pyroelectric materials by heat-treating by inserting an ultra-thin metal layer between graphenes, Through this, it can not only greatly contribute to various sensor industries that require microminiaturization and ultra-precision, but also provide very important information value to the future bio industry and the academic and technical fields of 2D materials that require high-speed response and high sensitivity. .

[Manufacturing method of graphene-based sensor for detecting ultrafine thermal-optical information]

In addition, another aspect of the present invention provides a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information.

6 is a process diagram illustrating a method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention, and FIG. 7 is a process diagram for detecting ultrafine thermal-optical information according to another embodiment of the present invention. It is a process chart showing a manufacturing method of a graphene-based sensor.

Referring to FIG. 6, a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention is

transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10);

Depositing a metal layer on the first single-layer graphene sheet (S20);

forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); and

and converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40).

In addition, referring to FIG. 7, a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention is

transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10);

Depositing a metal layer on the first single-layer graphene sheet (S20);

forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30);

converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40);

Forming a source electrode and a drain electrode so as to be adjacent to each end of the functionalized graphene layer (S50);

Forming a gate insulating layer to contact the source electrode and the drain electrode while covering the functionalized graphene layer (S60); and

and forming a gate electrode on the gate insulating layer (S70).

Hereinafter, a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention will be described step by step in detail.

First, step S10 is a step of transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material.

The pyroelectric material is KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ) , PCT ((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ It can be.

The single-layer graphene sheet may be prepared using a method known in the art. For example, a single-layer graphene sheet may be prepared on a graphitization catalyst metal film using a gas phase method, a polymer method, or a liquid phase method. , but is not limited thereto.

Specifically, in the vapor phase method, graphene is formed on the surface of the graphitization catalyst by injecting the vapor phase carbon source into a chamber containing a film-type graphitization catalyst and heat-treating it at a predetermined temperature. The heat treatment temperature acts as an important factor in the production of graphene, and may be, for example, 300 to 2,000 °C, preferably 500 to 1,500 °C.

The polymer method is a process of bringing a liquid carbon-based material into contact with a graphitization catalyst metal film, and may be performed through a process of applying a carbon-containing polymer, which is a carbon-based material, onto the substrate. In the case of using a carbon-containing polymer as the carbon-based material, any general carbon-containing polymer can be used without limitation, but in the case of using a self-assembling polymer, the polymer is regularly arranged in a vertical direction on the catalyst surface to form a more dense structure. It becomes possible to form a fin. At least one self-assembly polymer selected from the group consisting of an amphiphilic polymer, a liquid crystal polymer, and a conductive polymer may be used as the self-assembly polymer forming the self-assembled film.

Polymerization of the carbon-containing polymer may be performed before or after coating the graphitization catalyst. That is, in the case where polymerization between carbon-containing polymers is induced before application on the graphitization catalyst, the carbon-based material layer may be formed by transferring the polymerized film obtained through a separate polymerization process onto the graphitization catalyst.

The carbon-containing polymer may be arranged on the graphitization catalyst by various coating methods, such as Langmuir-Blodgett, dip coating, spin coating, vacuum deposition, etc., on the catalyst surface. can be arranged in In particular, according to such an application method, the carbon-containing polymer may be applied entirely on the substrate or selectively applied on the graphitization catalyst.

In the liquid phase method, graphene may be formed by heat-treating a liquid carbon-based material in contact with a graphitization catalyst metal film. As such a liquid carbon-based material, an organic solvent may be exemplified, and any material containing carbon and thermally decomposable in the graphitization catalyst may be used without limitation, and a polar or non-polar organic material having a boiling point of 60 to 400 ° C. solvents may be used. As such an organic solvent, alcohol-based organic solvents, ether-based organic solvents, ketone-based organic solvents, ester-based organic solvents, organic acid organic solvents, etc. can be used, and can be easily adsorbed with graphitized metal catalysts, have good reactivity, and have reducing power. It is more preferable to use alcohol-based and ether-based organic solvents from the standpoint of being excellent. As such an alcohol-based organic solvent, monohydric alcohols and polyhydric alcohols, etc. may be used alone or in combination, and propanol, pentaol, hexanol, heptanol, octanol, etc. may be used as the monohydric alcohol, Polyhydric alcohols include propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, octylene glycol, tetraethylene glycol, neopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4- butanediol, 2,3-butanediol, dimethyl-2,2-butanediol-1,2 and dimethyl-2,2-butanediol-1,3, etc. can be used. The monohydric and polyhydric alcohols may include an ether group in addition to a hydroxyl group. After that, the heat treatment process may be performed in the same manner as the gas phase method described above.

In addition, the single-layer graphene sheet can be directly formed on a substrate without a separate carbon source. As such a substrate, a SiC wafer can be used, for example. On the SiC wafer, graphene grows epitaxially, and graphene can grow on both the silicon and carbon surfaces of the SiC wafer.

As the synthesis process conditions for forming the graphene, it may be performed at a temperature of about 1,000 °C to about 2,000 °C in a vacuum or inert atmosphere for about 1 minute to about 2 hours. The inert atmosphere means that the vessel is filled with an inert element such as argon or helium, and the pressure at this time may be in the range of about 100 torr to about 700 torr.

As a method of transferring the prepared single-layer graphene sheet, a method commonly used in the art may be used. For example, when the single-layer graphene sheet is formed on a catalytic metal, spin-coating a polymer on a substrate onto which graphene is to be transferred (step a); curing the polymer-coated substrate (step b); inverting the graphene formed on the catalytic metal and attaching the graphene-formed surface to the polymer-coated surface of the substrate (step c); Etching the catalytic metal used to form graphene (step d); and cleaning and drying the graphene-attached substrate (step e).

Next, step S20 is a step of depositing a metal layer on the first single-layer graphene sheet.

The metal used in the metal layer is from the group consisting of platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), silver (Ag) and gold (Au) It may be selected, but is not limited thereto.

The metal layer may be formed to have a thickness of 1 nm or more and less than 10 nm by atomic layer deposition (ALD). If the thickness of the metal layer is out of the above range, there is a problem in that the graphene is not sufficiently doped with a heterogeneous metal element during heat treatment, so that the graphene is not sufficiently provided with a semiconductor function.

Next, step S30 is a step of forming a graphene/metal/graphene sandwich structure by transferring the second single-layer graphene sheet on the metal layer.

The method of transferring the second single-layer graphene sheet may be performed in the same manner as the method of transferring the first single-layer graphene sheet described above.

Next, step S40 is a step of converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure.

The heat treatment may be performed in a vacuum state or an atmosphere of hydrogen, nitrogen, oxygen, or the like, and may be performed at 110 to 1,050 ° C. depending on the metal used in the graphene/metal/graphene sandwich structure. As an example, when indium is used as the metal layer, the phase transition temperature of indium, that is, the melting point (mp) is 156.6 ° C. If the heat treatment temperature exceeds the phase transition temperature of metal, graphene is caused by the phase transition of metal Since there is a problem in that defects occur during metal doping, the heat treatment may be performed at 110° C. below the phase transition temperature of metal.

By the heat treatment, metal atoms are doped into the graphene layer to change the work function of graphene, thereby creating a band gap in graphene to form a functionalized graphene layer with semiconductor characteristics.

Meanwhile, when the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention is manufactured as a transistor type device, steps S50 to S70 may be further included.

The step S50 is a step of forming a source electrode and a drain electrode so as to be adjacent to each end of the functionalized graphene layer, and step S60 is a gate insulating layer covering the functionalized graphene layer and contacting the source electrode and the drain electrode. The step S70 is a step of forming a gate electrode on the gate insulating layer.

The source electrode, the drain electrode, the gate insulating layer, and the gate electrode may use conventional materials used in device manufacturing in the art, and the formation method thereof is also the same as described above, so detailed descriptions are omitted to avoid redundant description. .

The method may further include forming finger electrodes connecting both ends of the gate electrode on the pyroelectric substrate.

The fabricated graphene-based sensor for detecting ultrafine thermal-optical information connects functionalized graphene with semiconductor properties added by heteroatom doping on a pyroelectric substrate in downward polarization, thereby increasing the hole or electron carrier concentration of the functionalized graphene layer. Since the greatly increased, the drain current effectively decreased or increased, and as shown in FIG. 10, it was confirmed that ultrafine thermal-light detection in the infrared region of 700 nm or more wavelength was also possible.

Therefore, the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention can operate at room temperature by using the pyroelectric properties of the functionalized graphene layer and the pyroelectric substrate, and can be used in various sensor industries requiring ultra-miniaturization and ultra-precision. In addition, it can provide very important information value to the future bio industry and the academic and technical fields of 2D materials, which require high-speed response and high sensitivity.

[How to control the band gap of graphene]

In addition, another aspect of the present invention provides a method for controlling a band gap of graphene.

The method for controlling the band gap of graphene according to the present invention

Transferring the first single-layer graphene sheet onto the substrate (S10);

Depositing a metal layer on the first single-layer graphene sheet (S20);

forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); and

Heat-treating the structure to convert the graphene/metal/graphene sandwich structure into a functionalized graphene layer (S40);

The method for controlling the bandgap of graphene according to the present invention is characterized in that a graphene/metal/graphene sandwich structure is heat-treated to convert it into a functionalized graphene layer in which a bandgap is generated, and the steps of S10 to S40 are described above. As described in [Method of manufacturing graphene-based sensor for detecting ultrafine thermal-optical information], a detailed description is omitted to avoid redundant description.

Hereinafter, preferred manufacturing examples and experimental examples are presented to aid understanding of the present invention. However, the following Preparation Examples and Experimental Examples are only for helping understanding of the present invention, and the present invention is not limited by the following Preparation Examples and Experimental Examples.

[Production Example 1]

A 2-inch 6H-SiC wafer (0001) was placed in a chamber filled with 680 torr of argon gas and heated at 1,200 °C for 10 minutes. Then, it was slowly cooled to form an epitaxial single-layer graphene sheet having a size of 1 mm × 10 mm. This was repeated to form two single-layer graphene sheets.

After the formed single-layer graphene sheet was transferred onto a PZT substrate, an indium (In) layer was formed thereon to a thickness of 3 nm by atomic layer deposition (ALD).

A graphene/indium/graphene structure was formed by transferring a single-layer graphene sheet on the indium layer again.

Thereafter, the graphene/indium/graphene structure is heat-treated at 110° C. in a vacuum, hydrogen, nitrogen, or oxygen atmosphere to form a functionalized graphene layer on a pyroelectric substrate. A graphene-based sensor for detecting ultrafine thermo-optical information. was manufactured.

[Production Example 2]

A 2-inch 6H-SiC wafer (0001) was placed in a chamber filled with 680 torr of argon gas and heated at 1,200 °C for 10 minutes. Subsequently, it was slowly cooled to form an epitaxial single-layer graphene sheet having a size of 1 mm × 10 mm. This was repeated to form two single-layer graphene sheets.

After the formed single-layer graphene sheet was transferred onto a PZT substrate, an indium (In) layer was formed thereon to a thickness of 3 nm by atomic layer deposition (ALD).

A graphene/indium/graphene structure was formed by transferring a single-layer graphene sheet on the indium layer again.

Thereafter, the graphene/indium/graphene structure was heat treated at 110° C. under an oxygen atmosphere to form a functionalized graphene layer on the pyroelectric substrate.

Thereafter, a metal layer made of gold, platinum, or aluminum was deposited adjacent to each end of the functionalized graphene layer to form a source electrode and a drain electrode.

Next, a gate insulating layer was formed on the functionalized graphene layer by depositing aluminum oxide to cover the functionalized graphene layer and contact the source and drain electrodes.

Thereafter, a gate electrode (Au) was formed by depositing on the gate insulating layer.

[Experimental Example: Measurement of change in graphene properties by heat treatment of graphene/metal/graphene structure in a graphene-based sensor for detecting ultrafine thermal-optical information]

In the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, graphene/metal/graphe of Preparation Example 1 to examine the change in graphene characteristics according to heat treatment of the graphene/metal/graphene structure Before and after heat treatment of the fin structure was measured by Raman spectroscopy and shown in FIG. 8 , and the intensity mapping of the G band of graphene was analyzed and shown in FIG. 9 .

In addition, in the graphene-based sensor for detecting ultrafine thermal-optical information of Preparation Example 1, light detection intensity according to wavelength before and after heat treatment was measured and shown in FIG. 10 .

8 is a Raman spectroscopy spectrum showing functionalization of graphene before and after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.

As shown in FIG. 8, there is a change in peak intensity before and after heat treatment of the graphene/metal/graphene structure, but the position of the peak does not change, and the peak representing 2D graphene is maintained at about 2700 cm ^-1 position. It was found that high electrical conductivity was maintained because the graphene structure was maintained even during the functionalization of graphene. Therefore, in the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, the heat treatment of the graphene/metal/graphene structure creates a band gap by doping the metal without damaging the graphene itself. It can be seen that semiconductorization of graphene is achieved while maintaining the inherent physical properties such as high mobility.

9 illustrates G band intensity mapping of graphene after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.

As shown in FIG. 9, it can be seen that after the heat treatment of the graphene/metal/graphene structure, a band gap can be created while the G band intensity of graphene is non-uniformly generated, thereby achieving semiconductorization of graphene. .

10 is a graph showing light detection intensity according to wavelength before and after heat treatment of a graphene-based sensor for detecting ultrafine thermal-optical information according to an embodiment of the present invention.

As shown in FIG. 10, in the graphene-based sensor for detecting ultrafine thermal-optical information according to the present invention, the graphene/metal/graphene structure had very low light detection sensitivity in the infrared region (circle) before heat treatment, but , after heat treatment, it was confirmed that the photodetection sensitivity in the infrared region significantly increased, and thus it could function usefully as a sensor for detecting ultrafine thermal-optical information.

Although the present invention has been described above with reference to preferred embodiments, it should be understood that the present invention is not limited to the above embodiments. The present invention can make various changes and modifications to the above embodiments within the scope of the following claims, all of which fall within the scope of the present invention. Accordingly, this invention is limited only by the claims and equivalents thereto.

10: pyroelectric substrate
20: functionalized graphene layer
21, 22: single-layer graphene sheet
23: metal layer
30: drain electrode
40: source electrode
50: gate insulation layer
60: gate electrode
61, 62: finger type electrode
61, 62: finger type electrode

Claims (20)

a pyroelectric substrate containing a pyroelectric material; and
Including a functionalized graphene layer formed on the pyroelectric substrate,
Characterized in that the functionalized graphene layer is prepared by heat-treating a graphene / metal / graphene sandwich structure in which a metal layer is inserted between two single-layer graphene sheets,
A graphene-based sensor for detecting ultrafine thermo-optical information. a pyroelectric substrate containing a pyroelectric material;
a functionalized graphene layer formed on a portion of the pyroelectric substrate;
a source electrode and a drain electrode formed on the pyroelectric substrate to be adjacent to respective ends of the functionalized graphene layer;
a gate insulating layer formed on the functionalized graphene layer and contacting the source electrode and the drain electrode while covering the functionalized graphene layer; and
A gate electrode formed on the gate insulating layer;
Characterized in that the functionalized graphene layer is prepared by heat-treating a graphene / metal / graphene sandwich structure in which a metal layer is inserted between two single-layer graphene sheets,
A graphene-based sensor for detecting ultrafine thermo-optical information. According to claim 1 or 2,
The pyroelectric material is KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ) , PCT((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ Characterized in that, ultrafine thermo-graphene-based sensor for detecting optical information. According to claim 1 or 2,
The functionalized graphene layer is graphene for ultrafine thermo-optical information detection, characterized in that the work function of graphene is modified by heat treatment of the graphene/metal/graphene sandwich structure to generate a band gap, thereby exhibiting semiconductor characteristics. based sensor. According to claim 1 or 2,
In the graphene/metal/graphene sandwich structure, the metal is platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), magnesium (Mg) , A graphene-based sensor for detecting ultra-fine thermal-optical information, characterized in that selected from the group consisting of silver (Ag) and gold (Au). According to claim 1 or 2,
Characterized in that the metal layer has a thickness of 1 nm or more and less than 10 nm, a graphene-based sensor for detecting ultrafine thermal-optical information. According to claim 1 or 2,
Characterized in that the heat treatment is performed at 110 to 1,050 ° C. depending on the metal constituting the graphene / metal / graphene sandwich structure, a graphene-based sensor for detecting ultrafine thermal-optical information. According to claim 2,
The graphene-based sensor for detecting ultrafine thermal-optical information further comprises finger electrodes connecting both ends of the gate electrode. transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10);
Depositing a metal layer on the first single-layer graphene sheet (S20);
forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30); and
Heat-treating the structure to convert the graphene/metal/graphene sandwich structure into a functionalized graphene layer (S40),
Manufacturing method of graphene-based sensor for detecting ultrafine thermal-optical information. transferring a first single-layer graphene sheet onto a pyroelectric substrate including a pyroelectric material (S10);
Depositing a metal layer on the first single-layer graphene sheet (S20);
forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30);
converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40);
Forming a source electrode and a drain electrode so as to be adjacent to each end of the functionalized graphene layer (S50);
Forming a gate insulating layer to contact the source electrode and the drain electrode while covering the functionalized graphene layer (S60); and
Forming a gate electrode on the gate insulating layer (S70),
Manufacturing method of graphene-based sensor for detecting ultrafine thermal-optical information. The method of claim 9 or 10,
The pyroelectric material is KDP (KH ₂ PO ₄ ), ADP (NH ₄ H ₂ PO ₄ ), PZT (Pb(Zr,Ti)O ₃ ), PT(PbTiO ₃ ), PLT ((Pb,La)TiO ₃ ) , PCT((Pb,Ca)TiO ₃ ), LiTaO ₃ , BaTiO ₃ , TGS (triglycine sulfate), PVDF (polyvinylidenedifluoride), La ₃ Ga ₅ SiO ₁₄ , and LiNbO ₃ Characterized in that, a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information. The method of claim 9 or 10,
The metal is a group consisting of platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), magnesium (Mg), silver (Ag) and gold (Au). A method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information, characterized in that selected from. The method of claim 9 or 10,
Characterized in that the metal layer is formed by atomic layer deposition (ALD), a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information. The method of claim 9 or 10,
The method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information, characterized in that the metal layer has a thickness of 1 nm or more and less than 10 nm. The method of claim 9 or 10,
Characterized in that the heat treatment is performed at 110 to 1,050 ° C. depending on the metal constituting the graphene / metal / graphene sandwich structure, a method for manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information. According to claim 10,
A method of manufacturing a graphene-based sensor for detecting ultrafine thermal-optical information, characterized in that it further comprises forming finger electrodes connecting both ends of the gate electrode on a pyroelectric substrate. Transferring the first single-layer graphene sheet onto the substrate (S10);
Depositing a metal layer on the first single-layer graphene sheet (S20);
forming a graphene/metal/graphene sandwich structure by transferring a second single-layer graphene sheet on the metal layer (S30);
Converting the graphene/metal/graphene sandwich structure into a functionalized graphene layer by heat-treating the structure (S40); including, a method for controlling a band gap of graphene. According to claim 17,
Metals used in the metal layer include platinum (Pt), aluminum (Al), indium (In), nickel (Ni), cobalt (Co), manganese (Mn), magnesium (Mg), silver (Ag), and gold (Au). ) Characterized in that selected from the group consisting of, graphene bandgap control method. According to claim 17,
Characterized in that the metal layer has a thickness of 1 nm or more and less than 10 nm, graphene bandgap control method. According to claim 17,
The heat treatment is performed at 110 to 1,050 ° C. according to the metal constituting the graphene / metal / graphene sandwich structure.

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