阅读说明：本技术 一种石墨烯薄膜的制备方法 (Preparation method of graphene film ) 是由 朱虹延 吴天如 陈吉 张超 时志远 于广辉 于 2019-10-28 设计创作，主要内容包括：本发明涉及二维材料制备技术领域,特别涉及一种石墨烯薄膜的制备方法,包括：在碳化硅基底上设置催化剂得到反应样品；将所述反应样品加热至第一预设温度；将所述反应样品保温第一预设时长；其中,所述催化剂的熔点低于第一预设温度,所述催化剂的沸点高于第一预设温度；所述碳化硅基底包含的硅原子能够溶解在液态的所述催化剂中。本发明采用液态催化剂,以碳化硅为基底及固态碳源,通过高温催化碳化硅热分解,并在液态催化剂中溶解硅原子,剩余碳原子在液态催化剂与碳化硅的界面处重排,生成石墨烯。无需额外气态碳源,降低了制备过程中的工艺难度,且所得石墨烯无需转移,在电子器件等方面具有巨大的应用潜力。(The invention relates to the technical field of two-dimensional material preparation, in particular to a preparation method of a graphene film, which comprises the following steps: arranging a catalyst on a silicon carbide substrate to obtain a reaction sample; heating the reaction sample to a first preset temperature; keeping the reaction sample at the temperature for a first preset time; the melting point of the catalyst is lower than a first preset temperature, and the boiling point of the catalyst is higher than the first preset temperature; the silicon carbide substrate contains silicon atoms that are soluble in the catalyst in a liquid state. According to the method, a liquid catalyst is adopted, silicon carbide is used as a substrate and a solid carbon source, the silicon carbide is subjected to thermal decomposition through high-temperature catalysis, silicon atoms are dissolved in the liquid catalyst, and the residual carbon atoms are rearranged at the interface of the liquid catalyst and the silicon carbide, so that the graphene is generated. And an additional gaseous carbon source is not needed, the process difficulty in the preparation process is reduced, and the obtained graphene does not need to be transferred, so that the graphene has great application potential in the aspects of electronic devices and the like.)

1. A preparation method of a graphene film is characterized by comprising the following steps:

arranging a catalyst on a silicon carbide substrate to obtain a reaction sample;

heating the reaction sample to a first preset temperature;

keeping the reaction sample at the temperature for a first preset time;

the melting point of the catalyst is lower than a first preset temperature, and the boiling point of the catalyst is higher than the first preset temperature; the silicon carbide substrate contains silicon atoms that are soluble in the catalyst in a liquid state.

2. The method according to claim 1, wherein the first predetermined temperature is 800 ℃ to 1300 ℃.

3. The method of claim 2, wherein the catalyst is a metallic material.

4. The method according to claim 3, wherein the metal material is one or more selected from gallium, germanium, bismuth, indium, palladium and copper.

5. The method of claim 1, wherein the heating the reaction sample to a first predetermined temperature comprises:

placing the reaction sample in a reaction device;

introducing carrier gas into the reaction device to enable the pressure in the reaction device to be within a preset pressure range;

heating the reaction sample to the first preset temperature.

6. The production method according to claim 5, wherein the preset pressure range is 10Pa to 10000 Pa.

7. The production method according to claim 6, wherein the carrier gas comprises argon gas, or a mixed gas of hydrogen gas and argon gas.

8. The method according to claim 7, wherein the carrier gas is a mixed gas of hydrogen and argon, and the ratio of the hydrogen to the argon is 1:2 to 1: 300.

9. The method of manufacturing according to claim 1, further comprising: and removing the catalyst on the reacted sample to obtain the graphene film.

10. The method according to claim 9, wherein the removing the catalyst on the reacted sample after the reaction to obtain the graphene thin film comprises:

and removing the catalyst on the reacted reaction sample, putting the reaction sample into hydrochloric acid with preset concentration, and heating at a second preset temperature for a second preset time at constant temperature to remove the catalyst on the surface of the graphene film.

Technical Field

The invention relates to the technical field of two-dimensional material preparation, in particular to a preparation method of a graphene film.

Background

Graphene is a two-dimensional monatomic layered material arranged in a honeycomb grid structure, and the research field of two-dimensional materials is opened by related exploration after single-layer graphene is successfully separated by Geim and Novoseov in 2004 at the university of Manchester through a mechanical stripping method. The unique two-dimensional structural characteristics enable the graphene to have a plurality of unique physicochemical properties, such as high carrier mobility (250000 cm) at room temperature²V^-1S^-1) Ballistic transport characteristics in submicron scale, remarkable visible light transmission (2.3%), and special thermal conductivity (5000 Wm)^-1K^-1) And the excellent mechanical property of Young modulus up to 2.4TPa, so that the composite material has wide application prospect in the aspects of field effect transistors, integrated circuits, transparent conductive films, functional composite materials, energy storage materials and the like.

The high-quality graphene film can be prepared by a mechanical stripping method, but the cost is high, the efficiency is low, and the application of the graphene film in the field of devices is greatly limited. Chemical Vapor Deposition (CVD) is an effective means for batch production of single-layer and few-layer graphene continuous films. At present, high-quality and large-area graphene films are prepared on metal substrates such as Cu, Ni and Pt, but the graphene films have inevitable adverse effects on the crystal structure and the electrical properties of graphene in the transfer process, so that the graphene films cannot be applied on a large scale in the field of microelectronics at present. The SiC thermal decomposition method is an effective method for growing graphene on a dielectric substrate without transfer. And the SiC has chemical inertia, the electric field breakdown strength and the maximum current density are higher, and the graphene epitaxially grown on the surface of the SiC does not need an additional carbon source, so that the wide application of the graphene with the wafer size and the graphene device is favorably realized. However, the traditional silicon carbide thermal decomposition method for preparing graphene lacks participation of a catalyst in the Si-C decomposition process, needs to be carried out under high temperature (usually >1400 ℃) and ultra-high vacuum conditions, has harsh conditions and high requirements on the substrate crystal orientation, and is not beneficial to large-scale practical application. Therefore, the realization of the relatively low-temperature growth of graphene and the transfer-free growth of high-quality graphene thin films with controllable layer number on the dielectric substrate are still a great difficulty in research.

Disclosure of Invention

The invention aims to solve the technical problems of harsh preparation conditions and high cost of the existing graphene film preparation method.

In order to solve the technical problem, an embodiment of the application discloses a preparation method of a graphene film, which includes:

arranging a catalyst on a silicon carbide substrate to obtain a reaction sample;

heating the reaction sample to a first preset temperature;

keeping the reaction sample at the temperature for a first preset time;

the melting point of the catalyst is lower than a first preset temperature, and the boiling point of the catalyst is higher than the first preset temperature; the silicon carbide substrate contains silicon atoms that are soluble in the catalyst in a liquid state.

Further, the first preset temperature is 800-1300 ℃.

Further, the catalyst is a metal material.

Further, the metal material is one or more of gallium, germanium, bismuth, indium, palladium and copper.

Further, the heating the reaction sample to a first preset temperature includes:

placing the reaction sample in a reaction device;

introducing carrier gas into the reaction device to enable the pressure in the reaction device to be within a preset pressure range;

heating the reaction sample to the first preset temperature.

Further, the preset pressure range is 10Pa-10000 Pa.

Further, the carrier gas includes argon gas, or a mixed gas of hydrogen gas and argon gas.

Further, the carrier gas is a mixed gas of hydrogen and argon, and the ratio of the hydrogen to the argon is 1:2 to 1: 300.

Further, the preparation method further comprises the following steps: and removing the catalyst on the reacted sample to obtain the graphene film.

Further, the removing the catalyst on the reacted sample to obtain the graphene film includes:

and removing the catalyst on the reacted reaction sample, putting the reaction sample into hydrochloric acid with preset concentration, and heating at a second preset temperature for a second preset time at constant temperature to remove the catalyst on the surface of the graphene film.

By adopting the technical scheme, the preparation method of the graphene film has the following beneficial effects:

according to the preparation method of the graphene film, a high-catalytic liquid catalyst is used as a carrier, silicon carbide is used as a substrate and a solid carbon source, the silicon carbide is catalyzed at a high temperature to be thermally decomposed, silicon atoms are dissolved in the liquid catalyst, and the residual carbon atoms are rearranged at the interface of the liquid catalyst and the silicon carbide to generate the graphene. The method provided by the application does not need an additional gaseous carbon source, the process difficulty in the preparation process is reduced, the obtained graphene does not need to be transferred, and the method has great application potential in the aspects of electronic devices and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a method for preparing graphene according to an embodiment of the present disclosure.

Fig. 2 is an SEM picture of a graphene thin film prepared in example 1 of the present application.

Fig. 3 is a Raman line of graphene on the surface of silicon carbide according to example 1 of the present application.

Fig. 4 is an SEM picture of a graphene thin film prepared in example 2 of the present application.

Fig. 5 is a Raman line of graphene on the surface of silicon carbide in example 2 of the present application.

Fig. 6 is an SEM picture of a graphene thin film prepared in example 3 of the present application.

Fig. 7 is a Raman line of graphene on the surface of silicon carbide according to example 3 of the present application.

Fig. 8 is an SEM picture of a graphene thin film prepared in example 4 of the present application.

Fig. 9 is a Raman line of graphene on the surface of silicon carbide according to example 4 of the present application.

Fig. 10 is an SEM picture of a graphene thin film prepared in example 5 of the present application.

Fig. 11 is a Raman line of graphene on the surface of silicon carbide in example 5 of the present application.

Fig. 12 is an SEM picture of a graphene thin film prepared in example 6 of the present application.

Fig. 13 is a Raman line of graphene on the surface of silicon carbide according to example 6 of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the present application. In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.