Preparation method of graphene-diamond composite material
By using high-energy electron beam bombardment on the surface of single crystal diamond, the performance damage and stability problems caused by graphene transfer technology in the prior art are solved, and the high-quality preparation of graphene-diamond composite materials is achieved. It has conductor or semiconductor characteristics and maintains excellent performance of diamond.
Patent Information
- Application Number
- CN202411256561.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-13
AI Technical Summary
In the existing research on graphene, the ABC stacked structure has small material size and the semiconductor performance has not been practical, the scalability and stability of the layer transfer technology affect the electrical properties of the composite structure, and the transfer process will destroy the performance of graphene.
The diamond film is deposited on the surface of single crystal diamond by microwave chemical vapor deposition and microwave plasma technology, and the carbon atoms are converted into graphene stacked structure through high-energy electron beam bombardment to form graphene-diamond composite materials, avoiding graphene transfer technology destruction.
It realizes the formation of graphene-diamond composite materials with conductor or semiconductor properties in situ without additional carbon sources, maintaining the high band-disconnection width, light transmittance and thermal conductivity of the diamond, and has good stability and is suitable for Used as a substrate.
Smart Images
Figure CN119121395A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of diamond composite materials, and in particular to a method for preparing a graphene-diamond composite material. Background Art
[0002] As silicon chips gradually approach physical limits, high-quality semiconductor chips have an increasing demand for new semiconductor materials. The structural diversity and electronic adjustability of carbon-based materials give semiconductor materials many excellent properties. Few-layer (3-10 layers) graphene has a rich and diverse stacking structure, and has different band structures and very different physical properties due to different interlayer couplings. For example, ABA stacked (hexagonal phase, referred to as 2H phase) three-layer graphene is a semi-metal, while ABC stacked (rhombohedral phase, referred to as 3R phase) is a semiconductor with adjustable energy gap. Currently, few-layer graphene is widely used in the preparation of substrates such as silicon carbide, silicon dioxide, cubic boron nitride, and copper alloys.
[0003] Due to the limitations of preparation means, methods, interference from substrate materials, etc., the material size in existing research reports on ABC stacked graphene is generally small (several micrometers or even nanometers), and its semiconductor properties cannot be put into practical use. Moreover, in order to reduce the adverse effects of the substrate, the study of electron transport in few-layer graphene involves layer transfer technology. This method has poor scalability and stability, and phase transitions will occur during the transfer process, further limiting the application of ABC stacked few-layer graphene. The preparation of high-quality, large-area few-layer graphene with controllable structure (number of layers and stacking order) on a suitable insulating substrate not only perfectly retains the characteristics of few-layer graphene in terms of electrical, optical and other physical properties, but also can synchronize with it in terms of mechanical properties such as bonding force, expansion coefficient, and heat dissipation. This is the key to making semiconductor graphene practical.
[0004] Currently, graphene is mainly prepared on copper sheets by CVD, and then prepared on silicon or silicon carbide substrates by layer transfer technology. The transfer process will have an adverse effect on the performance of graphene, and the stability of the transfer technology itself is also poor, which affects the electrical properties of the composite structure. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a method for preparing a graphene-diamond composite material, so as to achieve the purpose of preparing a graphene-diamond composite material with conductor and semiconductor properties without introducing an additional carbon source and avoiding the damage caused by the graphene transfer technology.
[0006] To achieve the above object, the technical solution of the present invention is as follows:
[0007] A method for preparing a graphene-diamond composite material comprises the following steps:
[0008] (1) depositing a diamond film on the surface of a single crystal diamond by microwave chemical vapor deposition, and preparing single crystal diamond films with upper and lower surfaces oriented in (100), (110) or (111) by slicing and polishing;
[0009] (2) Using microwave plasma technology, the surface of a single crystal diamond film is treated with hydrogen plasma to obtain a single crystal diamond with a hydrogen-terminated surface;
[0010] (3) In a high vacuum environment, a tungsten filament is used to generate thermal electrons, and a high-energy electron beam is generated by applying a high voltage to the thermal electrons. The high-energy electron beam is directed toward a single crystal diamond surface having a hydrogen-terminated surface by using a bias technology, and the single crystal diamond surface having a hydrogen-terminated surface is bombarded to convert the carbon atoms on the surface of the single crystal diamond into a graphene stacking structure, thereby obtaining a graphene-diamond composite material.
[0011] In the above scheme, in step (1), after slicing and polishing, the surface of the obtained single-crystal diamond film has a single crystal plane structure that is atomically flat.
[0012] In the above scheme, in step (2), the microwave power is 3KW, the surface temperature of the single crystal diamond film is 500-600°C, the hydrogen flow rate is 200sccm, and the hydrogenation time is 5 minutes.
[0013] In the above scheme, in step (3), the high vacuum environment is an environment with a vacuum degree less than 5*10-4Pa.
[0014] In the above scheme, in step (3), the tungsten filament current is 0.5A and the high voltage is 1-20KV.
[0015] In the above scheme, in step (3), the bombardment time is 5-300s, and the bombardment times are 1-10 times.
[0016] In the above scheme, in step (3), the graphene stacking structures obtained are of three types, namely ABA, ABC and two composites.
[0017] In the above scheme, in step (3), the surface of the graphene-diamond composite material obtained exhibits conductor or semiconductor properties.
[0018] Through the above technical solution, the method for preparing a graphene-diamond composite material provided by the present invention has the following beneficial effects:
[0019] The present invention bombards the surface of single crystal diamond with electron beams to convert the surface carbon atoms into graphene structures, forming a graphene-diamond composite structure in situ without introducing an additional carbon source. The high bandgap width, light transmittance, thermal conductivity and stability of diamond enable it to be directly used as a subsequent substrate, thus avoiding the damage caused by graphene transfer technology.
[0020] In addition, the present invention can control the area, number of layers, stacking method and quality of the graphene layer by controlling the electron beam energy, density and bombardment times when the electron beam bombards the surface of the single crystal diamond, thereby realizing the preparation of a graphene-diamond composite material with conductor and semiconductor properties. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.
[0022] Figure 1 The present invention is a schematic diagram of a method for preparing a graphene-diamond composite material disclosed in an embodiment of the present invention.
[0023] Figure 2 This is a high-resolution transmission electron microscopy photograph of the surface of the obtained composite material. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0025] The present invention provides a method for preparing a graphene-diamond composite material, such as Figure 1 As shown, the specific embodiments are as follows:
[0026] (1) Growth of single crystal diamond substrate:
[0027] Diamond film was deposited on the surface of single crystal diamond by microwave chemical vapor deposition method, and the vapor deposition gas was methane, hydrogen and oxygen. Single crystal diamond film with upper and lower surfaces oriented (100), (110) or (111) was prepared by slicing and polishing method, and the film thickness was 0.3mm. After slicing and polishing, the surface of the obtained single crystal diamond had a single crystal plane structure that was flat at the atomic level.
[0028] (2) Surface preparation of hydrogen-terminated single-crystal diamond films:
[0029] Using microwave plasma technology, a single crystal diamond with a hydrogen-terminated surface is obtained by treating the surface of a single crystal diamond film with hydrogen plasma; the microwave power is 3KW, the surface temperature of the single crystal diamond film is 500-600°C, the hydrogen flow rate is 200sccm, and the hydrogenation time is 5 minutes.
[0030] (3) Preparation of graphene-diamond composite structure by electron beam bombardment:
[0031] In a high vacuum environment (vacuum degree less than 5*10-4Pa), a tungsten filament is used to generate thermal electrons (tungsten filament current is 0.5A), and a high-energy electron beam is generated by applying a high voltage (10KV) to the thermal electrons; the high-energy electron beam is directed to a single crystal diamond surface with a hydrogen terminal surface using a bias technology, and the single crystal diamond surface with a hydrogen terminal surface is bombarded for 100s and 10 times, thereby converting the carbon atoms on the surface of the single crystal diamond into a graphene stacking structure to obtain a graphene-diamond composite material.
[0032] By controlling the high voltage potential, tungsten filament current, bombardment time, and bombardment times, the graphene transformation area, number of layers, stacking mode, and quality are controlled. The graphene stacking structure obtained is ABA, ABC, and two composites, with a total of three types. The surface of the graphene-diamond composite material exhibits conductor or semiconductor properties. The high-resolution transmission electron microscope photo of the composite surface is shown in Figure 1. Figure 2 As shown in the figure, it can be seen that the prepared composite material has an obvious layered structure, with the upper part being the graphene layer and the lower part being the single crystal diamond.
[0033] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a graphene-diamond composite material, characterized in that: The steps include: (1) depositing a diamond film on the surface of a single crystal diamond by microwave chemical vapor deposition, and preparing single crystal diamond films with upper and lower surfaces oriented in (100), (110) or (111) by slicing and polishing; (2) Using microwave plasma technology, the surface of a single crystal diamond film is treated with hydrogen plasma to obtain a single crystal diamond with a hydrogen-terminated surface; (3) In a high vacuum environment, a tungsten filament is used to generate thermal electrons, and a high-energy electron beam is generated by applying a high voltage to the thermal electrons. The high-energy electron beam is directed toward a single crystal diamond surface having a hydrogen-terminated surface by using a bias technology, and the single crystal diamond surface having a hydrogen-terminated surface is bombarded to convert the carbon atoms on the surface of the single crystal diamond into a graphene stacking structure, thereby obtaining a graphene-diamond composite material.
2. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (1), after slicing and polishing, the surface of the obtained single crystal diamond film has a single crystal plane structure that is atomically flat.
3. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (2), the microwave power is 3 KW, the surface temperature of the single crystal diamond film is 500-600° C., the hydrogen flow rate is 200 sccm, and the hydrogenation time is 5 minutes.
4. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (3), the high vacuum environment is an environment with a vacuum degree less than 5*10-4Pa.
5. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (3), the tungsten filament current is 0.5A and the high voltage is 1-20KV.
6. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (3), the bombardment time is 5-300 s, and the bombardment times are 1-10 times.
7. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (3), the graphene stacking structures obtained are of three types, namely ABA, ABC and two composite types.
8. The method for preparing a graphene-diamond composite material according to claim 1, characterized in that: In step (3), the surface of the obtained graphene-diamond composite material exhibits conductor or semiconductor properties.