Graphene modification method and application

Abstract

The invention discloses a graphene modification method and application, and relates to the technical field of semiconductors, and the method comprises the following steps: providing graphene; graphene with holes is obtained in an etching mode, and the holes are provided with edge areas; the method comprises the following steps: determining a target modification structure, selecting a corresponding target molecule and an anchor molecule according to the target modification structure, connecting the anchor molecule to an edge region of graphene through a surface reaction, and carrying out a connection reaction on the target molecule through a reaction site on the anchor molecule to obtain modified graphene, according to the scheme, the target molecules are connected to the edge area of the graphene through the anchor point molecules, so that directional connection between the molecules is ensured, different target molecules can be selected according to actual needs to meet specific application requirements, the method provides a highly controllable mode, and the method is suitable for industrial production. The method is used for designing and preparing the graphene-based composite material with specific functions.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method for modifying graphene and its application. Background Technology

[0002] Graphene, as a novel two-dimensional material, exhibits broad application potential in multiple fields due to its unique structure and excellent properties. Its high conductivity and good mechanical strength make it an ideal material for batteries and supercapacitors, significantly improving energy density and charging speed. For example, as an electrode material in lithium-ion and sodium-ion batteries, graphene can effectively shorten charging time and improve overall battery performance. Furthermore, graphene's applications in the sensor field are increasing. Utilizing its high sensitivity and fast response characteristics, graphene sensors can be used to detect biomolecules, gases, and chemical substances, providing efficient monitoring solutions. In nanodevices, graphene's excellent electrical and thermal properties make it a key material for constructing next-generation nanoelectronic devices, enabling more efficient electron transport and smaller device designs.

[0003] While significant progress has been made in the preparation technology of graphene composite materials, several key issues and challenges remain in practical applications. First, due to its unique structure, graphene is prone to aggregation and recombination into graphite, limiting its applicability in composite materials. Furthermore, graphene needs to maintain good performance stability under various environmental conditions, including the influence of temperature, humidity, and light. However, the properties of graphene can change due to oxidation, contamination, or other factors, posing a challenge to its long-term stability and reliability. Therefore, a method for the stable modification of high-quality graphene is urgently needed to prepare high-quality graphene composite materials with specific functions. Summary of the Invention

[0004] The main objective of this invention is to propose a method for modifying graphene, which aims to improve the existing structural defects and address the difficulty in obtaining porous graphene with precise atomic-level structures.

[0005] To achieve the above objectives, this invention proposes a method for modifying graphene, comprising the following steps: S10 provides graphene; S20. Graphene with pores is obtained by etching, wherein the pores have edge regions; S30. Determine the target modification structure, select the corresponding target molecule and anchor molecule according to the target modification structure, connect the anchor molecule to the edge region of the graphene through surface reaction, and the target molecule is connected through the reaction site on the anchor molecule to obtain the modified graphene.

[0006] In one embodiment, the graphene preparation step in step S10 includes: S101, Provide copper foil substrate; S102. Graphene is obtained by chemical vapor deposition on the copper foil substrate.

[0007] In one embodiment, step S20 includes: Under vacuum conditions, graphene with pores is obtained by etching the graphene with plasma under controlled conditions, and the pores have edge regions.

[0008] In one embodiment, the gas in the plasma includes hydrogen or oxygen.

[0009] In one embodiment, step S30 includes: The target modification structure is determined, and the corresponding target molecule and anchor molecule are selected according to the target modification structure. The anchor molecule is connected to the edge region of the graphene through surface reaction. The anchor molecule is excited by external stimulation to provide reaction sites, so that the target molecule can be connected through the reaction sites on the anchor molecule to obtain the modified graphene.

[0010] In one embodiment, the external stimulus includes light stimulation, heating, or plasma stimulation; and / or, The anchor molecules are used to connect with carbon atoms at the edge of the graphene; and / or, The anchor molecule includes a functional group, which includes at least one of hydroxyl, carboxyl, amino, and halogen groups.

[0011] In one embodiment, in step S30: multiple target molecules are set, and the multiple target molecules and the anchor molecules cover the edge region through multiple connection reactions to form the target modified structure, thereby obtaining the modified graphene.

[0012] In one embodiment, in step S30, after each of the multiple connection reaction steps, the graphene is cleaned and repaired using a solvent, which includes water, alcohol solvents, or organic solvents.

[0013] In one embodiment, step S30 is followed by: Step S40: Detect and characterize the modified graphene. The detection method includes Raman spectroscopy, and the characterization method includes atomic force microscopy.

[0014] The present invention provides a semiconductor device comprising modified graphene obtained by the graphene modification method described above.

[0015] The technical solution of the present invention firstly involves etching graphene using an etching technique to form a large number of pores on the graphene, and the pores having edge regions containing unsaturated carbon atoms, which serve as highly reactive sites and facilitate subsequent surface reactions. Utilizing these active sites, anchor molecules can then specifically attach to the graphene edges in the edge regions through surface reactions. Because anchor molecules possess specific functional groups or structural domains, they can selectively react with active sites on graphene to form stable chemical bonds that fix them onto the graphene. Finally, target molecules can be further connected to them through the reaction sites on the anchor molecules. This not only ensures directional connections between molecules but also allows for the selection of different target molecules to meet specific application requirements. This method provides a highly controllable approach for designing and preparing graphene-based composite materials with specific functions. Furthermore, this method modifies the edges of patterned graphene in the same vacuum system without removing or transferring the graphene, thus avoiding the introduction of impurities other than the functional molecules used for modification. Therefore, it ensures the cleanliness and quality of the graphene layer and the resulting graphene composite material. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content shown in these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the graphene modification steps in Example 1 of the present invention; Figure 2 This is a schematic diagram of the structure of the porphyrin molecule used in the graphene modification step of Examples 1-2 of the present invention; Figure 3 This is a schematic diagram illustrating the growth process of graphene modification in Example 1 of the present invention, in which porphyrin molecules are gradually connected to graphene along a direction perpendicular to the graphene edge using a multi-step reaction. Figure 4 This is a flowchart of the graphene modification steps in Example 2 of the present invention; Figure 5 This is a schematic diagram of graphene growth on a copper foil surface using the CVD method in Embodiment 1 of the present invention. Figure 6 This is a SEM image and trend diagram of the etched graphene in Embodiment 1 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] While significant progress has been made in the preparation technology of graphene composite materials, several key issues and challenges remain in practical applications. First, due to its unique structure, graphene is prone to aggregation and recombination into graphite, limiting its applicability in composite materials. Furthermore, graphene needs to maintain good performance stability under various environmental conditions, including the influence of temperature, humidity, and light. However, the properties of graphene can change due to oxidation, contamination, or other factors, posing a challenge to its long-term stability and reliability. Therefore, a method for the stable modification of high-quality graphene is urgently needed to prepare high-quality graphene composite materials with specific functions.

[0020] In view of this, the present invention proposes a method for modifying graphene, comprising the following steps: A method for modifying graphene, comprising the following steps: S10 provides graphene; S20. Graphene with pores is obtained by etching, wherein the pores have edge regions; S30. Determine the target modification structure, select the corresponding target molecule and anchor molecule according to the target modification structure, connect the anchor molecule to the edge region of the graphene through surface reaction, and the target molecule is connected through the reaction site on the anchor molecule to obtain the modified graphene.

[0021] The technical solution of the present invention firstly involves etching graphene using an etching technique to form a large number of pores on the graphene, and the pores having edge regions containing unsaturated carbon atoms, which serve as highly reactive sites and facilitate subsequent surface reactions. Utilizing these active sites, anchor molecules can then specifically attach to the graphene edges in the edge regions through surface reactions. Because anchor molecules possess specific functional groups or structural domains, they can selectively react with active sites on graphene to form stable chemical bonds that fix them onto the graphene. Finally, target molecules can be further connected to them through the reaction sites on the anchor molecules. This not only ensures directional connections between molecules but also allows for the selection of different target molecules to meet specific application requirements. This method provides a highly controllable approach for designing and preparing graphene-based composite materials with specific functions. Furthermore, this method modifies the edges of patterned graphene in the same vacuum system without removing or transferring the graphene, thus avoiding the introduction of impurities other than the functional molecules used for modification. Therefore, it ensures the cleanliness and quality of the graphene layer and the resulting graphene composite material.

[0022] It should be noted that a large number of holes are formed on the graphene sheets by etching. These holes have edge regions that can be used to connect and react to form the target pattern.

[0023] It is understandable that existing surface reaction methods generate a large number of byproducts on the surface. For example, molecule A may not only react with anchor molecules, but may also react itself to form other byproducts. However, the method proposed in this application utilizes the high selectivity of surface reactions, which allows the target molecule to achieve atomic-level precision control of the reaction site through anchor molecules. By using a reaction-clear preparation process, it can be ensured that no byproducts that affect the results remain on the surface.

[0024] Specifically, graphene, as a two-dimensional macroscopic material, has extremely high stability. Once a single molecule is connected to the edge of graphene, it can exist stably in the atmospheric environment, solving the problem of high environmental requirements. In addition, as a carbon-based material, graphene is not only compatible with molecular materials, but also has excellent conductivity, so it can be used as an electrode material and combined with external circuits.

[0025] In one embodiment, the graphene preparation step in step S10 includes: S101, Provide copper foil substrate; S102. Graphene is obtained by chemical vapor deposition on the copper foil substrate.

[0026] In this step, the copper foil has a strong catalytic ability, which can effectively control the number of graphene layers and defect density, and is conducive to the uniform growth of graphene. The carbon source gas (such as methane and acetylene) decomposes on the surface of the copper foil and diffuses to the surface to form a graphene lattice. The resulting graphene has clear edges, which provides a good foundation for subsequent selective etching and functionalization, and can also obtain high-quality, large-area, continuous single-layer or few-layer graphene films.

[0027] In one embodiment, step S20 includes: Under vacuum conditions, graphene with pores is obtained by etching the graphene with plasma under controlled conditions, and the pores have edge regions.

[0028] It should be noted that by using plasma to create controllable defects in the edge region of graphene as the starting point for the reaction, under vacuum conditions, graphene is etched by adjusting the plasma (such as H2 or O2 plasma) to form a large number of pores. These pores have edge regions, meaning that etching can expose more of the edge regions of graphene for the reaction to form the target modified structure.

[0029] In one embodiment, the plasma gas includes hydrogen or oxygen. This is because high-energy particles in the plasma can preferentially attack the edges and defect sites of the graphene. By adjusting parameters such as plasma power, time, and atmosphere, the etching degree and defect type can be precisely controlled. Furthermore, by adjusting parameters such as etching time, gas flow rate, and power, the size of the etched pattern can be controlled, thereby controlling the edge E / area ratio S of the graphene. By controlling the E / S ratio, the subsequent target molecules, such as the size and number of target molecules, can be regulated.

[0030] In one embodiment, step S30 includes: The target modification structure is determined, and the corresponding target molecule and anchor molecule are selected according to the target modification structure. The anchor molecule is connected to the edge region of the graphene through surface reaction. The anchor molecule is excited by external stimulation to provide reaction sites, so that the target molecule can be connected through the reaction sites on the anchor molecule to obtain the modified graphene.

[0031] It should be noted that anchor molecules act as "bridges" to connect graphene defect regions with target molecules. External stimuli enhance the reactivity of anchor molecules and improve connection efficiency. Different anchor molecules can be designed according to actual functional requirements, such as those containing functional groups such as hydroxyl, carboxyl, amino, and halogen groups to achieve diverse modification pathways.

[0032] In one embodiment, the external stimulus includes light irradiation, heating or plasma methods. Since external stimuli (such as ultraviolet light or heat) can activate specific chemical bonds or functional groups in anchor molecules, promote their coupling reaction with target molecules, and enhance reactivity.

[0033] The anchor molecules are used to connect with carbon atoms at the edge of the graphene, and the anchor molecules can provide an intermediate connection platform to enhance the selectivity and diversity of the reaction.

[0034] The anchor molecule includes a functional group, which includes at least one of hydroxyl, carboxyl, amino and halogen groups. This is because the edge region contains unsaturated carbon atoms or functional groups, which are easy to covalently or non-covalently bond with the anchor molecule. The anchor molecule has specific functional groups (such as -NH2, -COOH, -X), which can further react with the target molecule to obtain a specific modified structure.

[0035] In one embodiment, in step S30: multiple target molecules are set, and the multiple target molecules and the anchor molecules cover the edge region through multiple connection reactions to form the target modified structure, thereby obtaining the modified graphene.

[0036] This method constructs complex structures through stepwise, hierarchical modifications, with each layer's connection and reaction built upon the previous layer, achieving an ordered construction from simple to complex.

[0037] In one embodiment, in step S30, after each of the multiple connection reaction steps, the graphene is cleaned and repaired using a solvent, which includes water, alcohol solvents, or organic solvents.

[0038] The choice of different solvents depends on the polarity and solubility of the molecules used, ensuring that impurities are effectively removed without damaging the modified structure. Unreacted molecules and byproducts, i.e. products not connected to the graphene edge, are removed through the cleaning step, thereby controlling the products present on the surface, improving the purity and uniformity of the modification, making the target modified structure more complex and functionally diverse, and enhancing the overall performance of graphene.

[0039] It should be noted that the etching process creates numerous edge regions within the original monolayer graphene. Then, the edges are modified through the reaction between anchor molecules and target molecules, partially refilling these edge regions. However, some edge regions will remain unfilled. These defects can significantly alter the electrical properties of graphene, such as reducing its conductivity and structural strength. If the density or area of ​​the unfilled regions is much smaller than the original graphene size, the impact on the electrical properties and structural strength is negligible, and therefore, no treatment is necessary. Alternatively, if the performance of the target graphene composite material is not sensitive to the impact of defects on electrical properties, no treatment is also optional.

[0040] Furthermore, by selecting appropriate organic functional molecules and conducting surface reactions, a reaction method similar to edge modification can be adopted. Appropriate reactive molecules or catalysts can be used to promote the repair reaction, thereby ensuring the integrity of the graphene structure and its good electronic properties. The repaired graphene not only has a lower defect density, but also restores its excellent electrical conductivity and mechanical properties.

[0041] Specifically, the repair steps using graphene are as follows: 1) In the repair process of graphene materials, choosing conjugated small molecules based on benzene rings as repair agents has significant advantages. Because benzene rings have good electronic conjugation effects and strong stability, and their chemical structure is similar to graphene, they can effectively interact with the graphene surface to repair its defects. The specific steps are as follows: 2) Determine the repair scheme. Different repair schemes can be adopted depending on the defect density and type, as well as the conductivity and structural stability requirements of the target graphene composite material. For example, for smaller edge regions, smaller conjugated small molecules with benzene ring structures, such as styrene, biphenyl, and anthracene, can be used. In addition, highly reactive groups can be introduced to improve the bonding efficiency. The target reaction mode typically requires a substrate metal as a reaction catalyst, such as Ullmann-coupling. The selected small molecules can self-assemble into the defects in the graphene, stabilizing the edge region through chemical bonding.

[0042] 3) Repairing the edges of the graphene. This step mainly includes four sub-steps, which can be repeated multiple times until the target repair effect is achieved.

[0043] 3.1 Adhesion and Repair Molecules: Similar to the aforementioned surface reactions, gas-phase and liquid-phase methods can be employed. For example, in liquid-phase methods, selected benzene ring-based conjugated small molecules can be dissolved in a suitable solvent, commonly including alcohols, ketones, or organic solvents. This solution is then uniformly coated onto the graphene surface to form a thin film, or the graphene can be immersed in the target solvent, allowing the small molecule repair agent to effectively adsorb and bind to the graphene edge regions.

[0044] 3.2 Activation of the Repair Reaction: Heating, ultraviolet irradiation, or the addition of a catalyst promotes the reaction between small molecules and the graphene surface. Conjugated small molecules bind to the edges of the graphene edge regions through dehydrogenation reactions or other coupling reactions, filling missing areas and thus repairing the graphene structure. The reaction mode used here requires the participation of a substrate metal for catalysis. Because the reaction is inert on the graphene surface, the related reaction cannot be reversed on the graphene surface. Therefore, the target reaction stops once the edge regions are filled with unexposed metal deposits at the bottom. Thus, this reaction is self-limiting, does not destroy the monolayer structure of graphene, and does not introduce additional structures.

[0045] 3.3 Cleaning and Impurity Removal: Similar to the method used in step three, impurities can be removed from the reacted graphene layer using gas or solution cleaning. Then, residual adsorbed gas or solvent is removed by heating. Finally, a clean graphene material meeting the requirements is obtained.

[0046] 3.4 Real-time inspection of repair quality. The quality of graphene after each repair step is rapidly detected online using spectroscopic methods such as Raman spectroscopy.

[0047] 4) Inspect the repair quality. After all repair work is completed, the quality of the graphene is comprehensively tested using optical microscopy, atomic force microscopy, and Raman spectroscopy. In addition, electrical testing methods can be used to test the conductivity of the graphene. Finally, it is confirmed that the obtained graphene composite material meets the performance requirements.

[0048] In one embodiment, step S30 is followed by: Step S40: Detect and characterize the modified graphene. The detection method includes Raman spectroscopy, and the characterization method includes atomic force microscopy.

[0049] In this invention, characteristic peaks such as the D peak and G peak can be identified by Raman spectroscopy to determine the defect density and degree of modification, thereby detecting the structural integrity and modification status of graphene. Atomic force microscopy (AFM) is used to characterize its surface morphology and thickness. The success of the modification is verified through comprehensive detection methods, providing a basis for subsequent applications.

[0050] This invention provides a semiconductor device comprising modified graphene obtained by the graphene modification method described above. The semiconductor device provided by this invention has all the technical solutions of all graphene modification methods, and therefore has all the beneficial effects of the graphene modification methods, which will not be elaborated here.

[0051] The present invention will be further described below with reference to specific embodiments.

[0052] Example 1 (using porphyrin molecules as the core molecular structure as an example) 1) Preparation of graphene Graphene was grown on liquid copper (at 1320 K) via chemical vapor deposition (PECVD). A 2% CH4 / Ar and H2 mixture was added to the reactor at a total pressure of 200 mbar using a gas handling system. The flow rates were argon (Ar) 200 sccm, hydrogen (H2) 5-20 sccm, and methane (CH4) 0.1-20 sccm. The methane (CH4) component catalytically dissociated on the liquid copper, releasing carbon atoms that formed a graphene layer on the surface, specifically as follows... Figure 5 As shown, where, Figure 5 In this context, 'a' represents the preparation process flow. Figure 5 In the image, b is a scanning electron microscope image of the obtained graphene. Figure 5 In the image, 'c' represents an atomic force microscope image of the obtained graphene. Figure 5 Figure a demonstrates the importance of precise temperature and time control in the synthesis of graphene. The different temperature ranges were designed to achieve stepwise molecular self-assembly and covalent bonding, ensuring that the final product has the expected structure and properties. Figures b and c show the morphological characteristics of graphene from macroscopic (SEM) and microscopic (AFM) perspectives, respectively.

[0053] 2) For the graphene prepared in step 1), graphene with holes is obtained by etching, wherein the holes have edge regions.

[0054] 3) Determine the target modification structure. In this embodiment, the modification and extension are carried out along the direction perpendicular to the graphene. Based on the target modification structure, the corresponding target molecule and anchor molecule are selected, and the following is adopted: Figure 2 The middle molecule b serves as the anchor molecule. The anchor molecule has a bromophenyl group with high reactivity. It can remove bromine atoms under the catalytic effect of heating on a metal substrate to form a free radical, which then reacts with carbon atoms at the edge of the pores in the graphene.

[0055] 4) After completing the molecular attachment and reaction activation steps, byproducts can be removed by conventional gas or solution cleaning, retaining the molecules connected to the graphene edge. Through these steps, a single-step reaction is completed. Subsequently, by continuously using the same molecule b as the target molecule and repeating the above process, multi-step controllable modification of the graphene edge can be achieved, yielding the desired result. Figure 3 The modified graphene shown.

[0056] Specifically, solution washing is a crucial step in removing physically and chemically adsorbed byproducts after the covalent bonding reaction between the molecules and the graphene edges is completed. The core of this process lies in selectively removing byproducts by utilizing the difference in stability of covalent bonds and the solubility of byproducts in the solvent. Typically, strongly polar solvents such as N-methylpyrrolidone (NMP) or dimethylformamide (DMF) are preferred for initial immersion washing of the sample. These solvents effectively dissolve the vast majority of unreacted raw material molecules and physically adsorbed impurities. Subsequently, a gradual solvent gradient displacement washing is performed, using acetone and isopropanol (IPA) sequentially to remove residual strong solvents and further purify the sample.

[0057] The final stage involves rinsing with deionized water to dissolve and remove any residual inorganic salt byproducts. Gentle nitrogen blowing is recommended during drying to avoid residue contamination that may result from surface tension, ensuring a clean and structurally intact sample. High-intensity ultrasonic treatment should be avoided throughout the cleaning process to prevent damage to the graphene's microstructure or breakage of existing covalent bonds.

[0058] 5) The modified graphene in step 4) is repaired, and the resulting modified and repaired graphene composite material is transferred to an insulating substrate by wet process and integrated with a metal electrode to fabricate a device, thereby obtaining a semiconductor device with the modified graphene of the present invention.

[0059] It should be noted that the repair is mainly aimed at enhancing the electrical properties and structural stability of the composite material.

[0060] The main method involves vapor-depositing small aromatic molecules, such as biphenyl (two benzene rings connected by a single bond), onto the graphene surface to be repaired. Because the surface hydrocarbon reaction requires the catalysis of a metal substrate and the graphene edge has higher activity, under the influence of external conditions (heat, light, and electrons), biphenyl will react with molecules connected to the graphene edge in the substrate plane in the edge region, thereby achieving the goal of filling the edge region.

[0061] Example 2 Except for step 3, the rest are similar to Example 1. Step 3 of Example 2 is as follows: 3) Determine the target modification structure. In this embodiment, we choose to modify the structure first along the direction perpendicular to the graphene and then expand it to the target modification structure parallel to the direction. First, we adopt... Figure 2 Using either molecule C or molecule D as the target molecule and a reaction temperature of 100℃, the iodophenyl group will be activated and participate in the reaction, while the bromophenyl group will not react. Therefore, if molecule C is used, the strip-like structure perpendicular to the edge of the graphene can be formed with high efficiency through the deiodination reaction of the iodophenyl group, resulting in a structure like... Figure 4 The structure of 'a' in the text.

[0062] Example 3 Except for step 3, the rest is similar to Example 1. Step 3 of Example 3 is as follows: 3) Determine the target modification structure and adopt... Figure 2 In this study, molecules c and d are used as target molecules. For molecule d, its horizontal connection is similar to that of molecule b. A similar structure can be obtained through a stepwise reaction. At the same time, by controlling the reaction steps, the length of the strip structure can be better controlled.

[0063] 4) After completing the molecular attachment and reaction activation steps, byproducts can be removed using conventional gas or solution methods, retaining the molecules connected to the graphene edge. After the previous step, a porphyrin molecular band perpendicular to the graphene edge is obtained, with unreacted bromophenyl groups on its sides. At this point, a target molecule with a bromo group can be introduced to react with the bromo groups of the already connected molecular band, thereby achieving modification parallel to the graphene edge. Specifically, a stepwise reaction is first used, as shown in Figure a, by activating the iodophenyl group, porphyrin molecules are gradually connected to the graphene along the direction perpendicular to the graphene edge. Then, the bromophenyl group is activated to achieve molecular modification parallel to the graphene edge, obtaining the desired result. Figure 4 The b structure in the text.

[0064] It should be noted that here Figure 2 In the diagram, 'a' represents a porphyrin molecule as the core, with the red position being the core structure. The four central carbon atoms (meso positions) can be equipped with different groups. By designing and using different substituents, the reaction pathway can be constrained, and a flexible and controllable functional structure can be provided.

[0065] Figure 2 The middle molecule b has two tert-butyl groups (top and bottom), which have low reactivity and can mainly limit the reaction pathway. Furthermore, halophenyl groups (such as bromine and iodine) have different activation temperatures. Therefore, there are three reaction modes: deiodination (temperature ~390K), where the two iodophenyl groups lose iodine atoms to form bonds; debromination (~470K), where the bromophenyl group undergoes a dehydrogenation reaction with the unattached carbon atom at the meso position to form a bond (>500K).

[0066] Molecules b can react with each other via a debromination reaction of two brominated groups, or by a debromination of one brominated group followed by a reaction with an unsubstituted meso-position carbon atom of another molecule (the position on the right side of molecule b without a group attachment). Of these three reactions, the dimer obtained through the two brominated groups has the lowest activation energy and is more readily formed; however, since there are no brominated groups after polymerization, the dimer will not continue to react. The reaction of the brominated group with another meso-position carbon atom is similar to the reaction with the edge of graphene. Considering that the exposed area of ​​the graphene edge is much larger than that of the molecule, from a kinetic perspective, the probability of the brominated group reacting with the graphene edge is much higher than the probability of intermolecular reactions. Therefore, a higher connection efficiency can be obtained at the graphene edge.

[0067] Porphyrin molecules are a common molecular structure found in the human body and nature, and are core components of heme and chlorophyll. By attaching different functional groups to four substituents, they can acquire different functions and constrain their reaction pathways on the surface. At the same time, a metal atom can be attached to the center, giving them unique abilities in gas adsorption and catalysis.

[0068] Performance testing The graphene prepared in Example 1 was subjected to performance testing. Figure 6 Images a through f: These images show the microstructure of the material at different temperatures (1020 K to 1170 K), specifically, as shown in... Figure 6 As shown, SEM images based on hydrogen etching are displayed. At a (1020 K): the image shows a relatively uniform surface without obvious cracks or holes. As the temperature increases, cracks and holes become more obvious and the surface becomes more uneven, reaching a maximum at f (1170 K), where the surface is almost completely destroyed. This indicates that the density of the etched part can be controlled by adjusting the temperature. exist Figure 6 In the graph g, the left side of the y-axis represents the size of the etched area (percentage), and the right side represents the length of the exposed edge (millimeters). The x-axis represents the temperature (K). The red solid line and dots represent the change in the size of the etched area with temperature, while the blue dashed line and squares represent the change in the length of the exposed edge with temperature. From the graph, we can see that the size of the etched area gradually increases with increasing temperature, reaching a maximum of about 80% at 1170 K. The length of the exposed edge first increases and then decreases with increasing temperature, reaching a maximum of about 5.5 mm at around 1090 K.

[0069] In summary, this demonstrates the changes in the microstructure of the material at different temperatures and the impact of these changes on the etched area and exposed edges. As the temperature increases, the microstructure of the material becomes more non-uniform, the etched area increases, and the length of the exposed edges first increases and then decreases.

[0070] The present invention has the following advantages in preparing the present invention: High quality: Graphene materials grown in situ via CVD can ensure the high quality of graphene composite materials, with fewer impurities and defects, thus ensuring the stability of material properties.

[0071] High purity: This method reduces impurities that may be introduced during graphene transfer by employing surface reaction modification and repair methods to maximize the purity of the graphene. This method requires only one transfer operation after the final preparation is complete.

[0072] High controllability: The modification of graphene edges by functionalized molecules is highly controllable, which can precisely regulate the chemical and physical properties of graphene, thereby stabilizing the performance of composite materials.

[0073] Various modifications and variations can be made to this invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of patent protection of this invention.

Claims

1. A method for modifying graphene, characterized in that, Includes the following steps: S10 provides graphene; S20. Graphene with pores is obtained by etching, wherein the pores have edge regions; S30. Determine the target modification structure, select the corresponding target molecule and anchor molecule according to the target modification structure, connect the anchor molecule to the edge region of the graphene through surface reaction, and the target molecule is connected through the reaction site on the anchor molecule to obtain the modified graphene.

2. The graphene modification method as described in claim 1, characterized in that, The graphene preparation steps in step S10 include: S101, Provide copper foil substrate; S102. Graphene is obtained by chemical vapor deposition on the copper foil substrate.

3. The method for modifying graphene as described in claim 1, characterized in that, Step S20 includes: Under vacuum conditions, graphene with pores is obtained by etching the graphene with plasma under controlled conditions, and the pores have edge regions.

4. The method for modifying graphene as described in claim 3, characterized in that, The plasma gas includes hydrogen or oxygen.

5. The method for modifying graphene as described in claim 1, characterized in that, Step S30 includes: The target modification structure is determined, and the corresponding target molecule and anchor molecule are selected according to the target modification structure. The anchor molecule is connected to the edge region of the graphene through surface reaction. The anchor molecule is excited by external stimulation to provide reaction sites, so that the target molecule can be connected through the reaction sites on the anchor molecule to obtain the modified graphene.

6. The method for modifying graphene as described in claim 5, characterized in that, The external stimulation includes light stimulation, heating stimulation, or plasma stimulation; and / or, The anchor molecules are used to connect with carbon atoms at the edge of the graphene; and / or, The anchor molecule includes a functional group, which includes at least one of hydroxyl, carboxyl, amino, and halogen groups.

7. The method for modifying graphene as described in claim 5, characterized in that, In step S30: multiple target molecules are set, and the multiple target molecules and the anchor molecules cover the edge region through multiple connection reactions to form the target modified structure, thereby obtaining the modified graphene.

8. The method for modifying graphene as described in claim 7, characterized in that, In step S30, after each of the multiple connection reaction steps, the graphene is cleaned and repaired using a solvent, which includes water, alcohol solvents, or organic solvents.

9. The method for modifying graphene as described in claim 1, characterized in that, Step S30 is followed by: Step S40: Detect and characterize the modified graphene. The detection method includes Raman spectroscopy, and the characterization method includes atomic force microscopy.

10. A semiconductor device, characterized in that, The semiconductor device includes modified graphene prepared by the method of graphene modification as described in any one of claims 1 to 9.

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