Two-dimensional layered amorphous material and preparation method thereof

Abstract

The preparation method comprises the following steps: forming a transfer medium layer on a single-layer or few-layer amorphous material on a substrate, soaking the transfer medium layer in water to enable the substrate to fall off, and drying to obtain a base; taking the amorphous material on the uppermost layer as a contact surface, attaching the substrate to another single-layer or few-layer amorphous material with a substrate, heating and attaching, soaking in water to enable the substrate to fall off, drying to obtain a transfer medium / laminated amorphous material, and repeating the step as the substrate until a target number of layers of two-dimensional amorphous materials are stacked and attached; and stripping the transfer medium layer. Compared with the prior art, the method has the advantages that different layers of amorphous materials are synthesized through stacking, and the electrical properties of the amorphous materials (amorphous carbon) can be effectively regulated and controlled in the vertical direction so as to meet different application requirements; the method can also be applied to preparation of controllable layers of other two-dimensional amorphous materials; the property and the performance of the two-dimensional layered amorphous material are regulated and controlled by regulating and controlling the interlayer interaction of the two-dimensional layered amorphous material, and the application range is expanded.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional layered materials technology, and relates to a two-dimensional layered amorphous material, its preparation method and application. Background Technology

[0002] The rise of two-dimensional layered materials has ushered in a new era for materials science and nanotechnology. Due to their layered structure and atomic-level thickness, two-dimensional materials not only retain the properties of bulk materials but also exhibit unique characteristics, showing great potential in next-generation electronics, optoelectronics, and energy applications. Because of interlayer coupling, the properties of two-dimensional layered materials are closely related to the number of layers. Interlayer spacing is a quantitative indicator of interlayer coupling, and controlling the interlayer spacing is a quantitative and visible way to regulate the properties of two-dimensional layered materials. For example, the band gap of black phosphorus can be adjusted by the number of layers. Calculations show that the band gap of black phosphorus decreases with increasing layer number, exhibiting an exponential change. As the number of layers decreases from 5 to 1, the band gap increases from 0.59 eV to 1.51 eV; when the number of layers reaches 10, the band gap decreases to 0.11 eV, very close to the value of bulk materials. Furthermore, two-dimensional layered materials can be assembled with identical / different two-dimensional layers vertically or laterally to form van der Waals homogeneous / heterogeneous structures, achieving new breakthroughs in the properties of two-dimensional layered materials, which greatly expands their application range.

[0003] To date, research on two-dimensional layered materials has primarily focused on crystalline materials, with limited research on amorphous materials. Compared to crystalline materials, amorphous materials lack long-range order and predictable atomic structures, making it difficult to synthesize two-dimensional amorphous materials with a controllable number of layers and to regulate their properties through interlayer interactions. Currently, no natural bulk of two-dimensional amorphous materials has been discovered; their layered stacking is randomly distributed, thus preventing top-down (exfoliation) methods. This means that synthesis methods are concentrated on bottom-up direct growth and phase transitions in crystalline materials. Various synthesized two-dimensional amorphous materials, including amorphous graphene, amorphous transition metal sulfides, amorphous black phosphorus, and amorphous boron nitride, exhibit properties different from two-dimensional crystalline materials and have been applied in electronics, optoelectronics, energy storage, and electrocatalysts. However, synthesizing two-dimensional amorphous materials with a specified number of layers, except for monolayer amorphous carbon, remains a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a two-dimensional layered amorphous material, its preparation method, and its application, which enables the preparation of a two-dimensional amorphous material with a controllable number of layers and achieves tunable properties through interlayer interactions.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a two-dimensional layered amorphous material, including a single-layer or few-layer amorphous material prepared by multilayer stacking.

[0007] Furthermore, the single-layer or few-layer amorphous material is a single-layer or few-layer amorphous carbon.

[0008] A second aspect of the present invention provides a method for preparing a two-dimensional layered amorphous material, comprising the following steps:

[0009] S1: A transfer dielectric layer is formed on a single layer or few layers of amorphous material on a substrate, then immersed in water to remove the substrate, and dried to obtain a transfer dielectric / single layer or few layers of amorphous material, denoted as the substrate;

[0010] S2: Using the topmost single-layer or few-layer amorphous material as the contact surface, attach the substrate to another single-layer or few-layer amorphous material with a substrate. After heating and bonding, immerse in water to remove the substrate, dry, and obtain the transfer medium / stacked amorphous material. Repeat step S2 as the substrate until the target number of two-dimensional amorphous materials are stacked and bonded on the transfer medium.

[0011] S3: Peel off the transfer medium layer to obtain a two-dimensional layered amorphous material.

[0012] Furthermore, the single-layer or few-layer amorphous material is a single-layer or few-layer amorphous carbon.

[0013] Further, in step S1, the transfer medium layer comprises polymethyl methacrylate and / or polystyrene.

[0014] Further, in step S1, the transfer medium layer is shaped by spin coating and drying.

[0015] Further, in step S1, the method for forming the transfer medium layer includes: spin-coating a polymethyl methacrylate (PMMA) solution onto a single layer or few layers of amorphous material to form a polymethyl methacrylate layer; and then spin-coating a polystyrene (PS) solution onto the polymethyl methacrylate layer to form a polystyrene layer;

[0016] The spin coating speeds for the polymethyl methacrylate solution and the polystyrene solution were 2000–3000 rpm, and the spin coating times were 40–80 s, respectively.

[0017] Furthermore, the method further includes: in step S1, attaching adhesive tape to the transfer medium layer to form an adhesive tape support, and drying it; preferably, during the drying process, the drying temperature is 65–75°C, and the drying time is 8–15 min; and,

[0018] In step S3, the tape is removed before peeling off the transfer medium layer.

[0019] Furthermore, in step S2, during the heating and bonding process, the heating temperature is 120–180°C, and the heating time is 5–15 minutes.

[0020] Furthermore, in step S3, before peeling off the transfer medium layer, a single layer or few layers of amorphous material are used as the contact surface to retrieve the product obtained in step S2 through the target substrate and dry it.

[0021] Furthermore, in step S3, the transfer medium layer is dissolved and peeled off.

[0022] Furthermore, the stripping solvent used is selected from one or both of toluene and acetone.

[0023] Compared with the prior art, the present invention has the following characteristics:

[0024] 1. This invention utilizes polymethyl methacrylate and polystyrene-assisted water transfer to achieve the stacking of single-layer or few-layer amorphous materials, enabling the preparation of amorphous materials with a controllable number of layers. This method is versatile and can achieve the controllable preparation of two-dimensional layered amorphous materials.

[0025] 2. This invention synthesizes amorphous carbon with different numbers of layers by stacking, which can effectively control the electrical properties of amorphous carbon in the vertical direction to meet different application requirements. It realizes the control of the properties and performance of two-dimensional amorphous materials by regulating the interlayer interactions, thus expanding the application range. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of a method for preparing two-dimensional layered amorphous carbon materials according to the present invention.

[0027] Figure 2 These are optical schematic diagrams (a, b, c) of a single-layer amorphous carbon (a, d) and 3-layer (b, e) and 7-layer (c, f) amorphous carbon obtained by stacking and transfer respectively in Example 1; AFM images and thicknesses (d, e, f).

[0028] Figure 3 The diagram shows (a) the amorphous carbon conductivity testing device in Example 2; and (b) the lateral conductivity of a single layer of amorphous carbon and the vertical conductivity of stacked amorphous carbon with different numbers of layers. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0030] The following are more detailed implementation examples, which further illustrate the technical solution of the present invention and the technical effects that can be obtained.

[0031] In the following embodiments, unless otherwise specified, the raw materials, reagents or processing techniques are all conventional commercial products or conventional processing techniques in the art.

[0032] In the following embodiments, the method for preparing a monolayer amorphous carbon sample on a mica substrate includes:

[0033] S1: Place 10 μg of 3,4,9,10-tetracarboxylic acid dianhydride perylene (PTCDA) powder as a carbon source in the center of the upstream region of the dual-temperature zone quartz tube furnace, and place a quartz boat containing a newly cleaved 1×1cm fluorinated phlogopite substrate in the center of the downstream region of the dual-temperature zone quartz tube furnace.

[0034] S2: Before growth begins, the growth system is purged and vented three times using 600 sccm of high-purity argon gas and a vacuum pump to remove residual water and oxygen from the system.

[0035] S3: The upstream temperature zone is preset to 600℃, the downstream temperature zone to 900℃, the gas flow rate is 50 sccm for argon and 5 sccm for hydrogen, the heating time is preset to 15 min, and the isothermal time is preset to 5 min. After the reaction is complete, the quartz tube is immediately removed and rapidly cooled to room temperature, thus obtaining a monolayer of amorphous carbon on the surface of fluorophlogopite.

[0036] Example 1:

[0037] A method for preparing two-dimensional layered amorphous carbon materials and transferring them to a target substrate, such as... Figure 1 As shown, it includes the following steps:

[0038] S1: First, PMMA (Suzhou Ruicai Semiconductor Co., Ltd., model: 495A4) was spin-coated onto a monolayer amorphous carbon surface on a mica substrate at a speed of 2500 rpm for 60 seconds, and then dried at a low temperature of 70°C for 10 minutes; then, PS chloroform solution (concentration 10wt%) was spin-coated onto the PMMA film at a speed of 2500 rpm for 60 seconds, and then dried at a low temperature of 70°C for 10 minutes to form PS / PMMA / monolayer amorphous carbon / mica;

[0039] S2: Use invisible tape (3M, USA) to apply around the edge of the PS film to form a tape support for easy operation;

[0040] S3: Insert the substrate obliquely into a petri dish containing pure water, and use capillary force to separate the Tape / PS / PMMA / monolayer amorphous carbon from the mica substrate, and dry it at a low temperature of 70°C.

[0041] S4: Place another monolayer amorphous carbon sample on a mica substrate tightly against the transferred monolayer amorphous carbon, and heat it at 150°C for 10 min to bond them together.

[0042] S5: After the substrate is tightly bonded, it is inserted into the water surface at an angle again to peel off the substrate and obtain a double-layer amorphous carbon, which is referred to as the transferred multilayer amorphous carbon.

[0043] S6: Place another single-layer amorphous carbon sample on a mica substrate tightly against the top layer of the transferred multilayer amorphous carbon, and heat it at 150°C for 10 minutes to bond them together.

[0044] S7: After the substrate is tightly bonded, it is inserted into the water surface at an angle again to peel off the substrate and obtain the transferred multilayer amorphous carbon. Repeat steps S6 to S7 until the target number of two-dimensional layered amorphous carbon material is obtained.

[0045] S8: Cut off all the tape, use the target substrate (mica) to pick up the two-dimensional layered amorphous carbon material, and dry it on a heating stage at 80°C for 30 minutes;

[0046] S9: The sample was immersed in toluene solution for 1 hour to remove the PS film, and in acetone solution for 1 hour to remove the PMMA film. After drying, a two-dimensional layered amorphous carbon material with the target number of layers was obtained and supported on the target substrate.

[0047] like Figure 2 The image shows (a, b, c) optical schematic diagrams of a single layer of amorphous carbon and 3-layer and 7-layer amorphous carbon obtained by stacking and transfer, respectively; (d, e, f) AFM images and thicknesses, indicating that the thickness of the single layer of amorphous carbon is approximately 0.39 nm, the thickness of the 3-layer amorphous carbon is approximately 1.46 nm, and the thickness of the 7-layer amorphous carbon is approximately 4.40 nm.

[0048] Example 2:

[0049] Vertically oriented electrical devices were constructed to test the electrical properties of stacked amorphous carbon with different numbers of layers. For example... Figure 3 (a) shows the amorphous carbon conductivity testing device. A bottom electrode (BE) made of Au is constructed on the SiO2 / Si surface. Different layers of amorphous carbon are transferred onto the bottom electrode surface, and then a top electrode (TE) made of Au or Ag is constructed on the amorphous carbon surface. A conductivity test is applied to this device from 0 to 16 × 10⁻⁶. 17 The electric field strength was measured at V / m. (b) The transverse conductivity of a single layer of amorphous carbon and the vertical conductivity of amorphous carbon with different stacking layers were measured. The results show that the vertical conductivity of amorphous carbon increases exponentially with the increase of the number of stacking layers. This phenomenon indicates that the electrical properties of amorphous carbon can be effectively controlled by adjusting the number of layers and the vertical stacking structure. This is of great significance for its application in future electronic devices.

[0050] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A two-dimensional layered amorphous material, characterized in that, This includes single-layer or few-layer amorphous materials prepared by multilayer stacking.

2. A method for preparing a two-dimensional layered amorphous material as described in claim 1, characterized in that, Includes the following steps: S1: A transfer dielectric layer is formed on a single layer or few layers of amorphous material on a substrate, then immersed in water to remove the substrate, and dried to obtain a transfer dielectric / single layer or few layers of amorphous material, denoted as the substrate; S2: Using the topmost single-layer or few-layer amorphous material as the contact surface, attach the substrate to another single-layer or few-layer amorphous material with a substrate. After heating and bonding, immerse in water to remove the substrate, dry, and obtain the transfer medium / stacked amorphous material. Repeat step S2 as the substrate until the target number of two-dimensional amorphous materials are stacked and bonded on the transfer medium. S3: Peel off the transfer medium layer to obtain a two-dimensional layered amorphous material.

3. The method for preparing a two-dimensional layered amorphous material according to claim 2, characterized in that, The single-layer or few-layer amorphous material is a single-layer or few-layer amorphous carbon.

4. The method for preparing a two-dimensional layered amorphous material according to claim 2, characterized in that, In step S1, the transfer medium layer comprises polymethyl methacrylate and / or polystyrene; the transfer medium layer is shaped by spin coating and drying.

5. The method for preparing a two-dimensional layered amorphous material according to claim 4, characterized in that, In step S1, the method for forming the transfer medium layer includes: spin-coating a polymethyl methacrylate solution onto a single layer or few layers of amorphous material to form a polymethyl methacrylate layer; and then spin-coating a polystyrene solution onto the polymethyl methacrylate layer to form a polystyrene layer. The spin coating speeds for the polymethyl methacrylate solution and the polystyrene solution were 2000–3000 rpm, and the spin coating times were 40–80 s, respectively.

6. The method for preparing a two-dimensional layered amorphous material according to claim 2, characterized in that, The method further includes: in step S1, attaching adhesive tape to the transfer medium layer to form an adhesive tape support and drying it; and in step S3, removing the adhesive tape before peeling off the transfer medium layer.

7. The method for preparing a two-dimensional layered amorphous material according to claim 6, characterized in that, In step S2, during the heating and bonding process, the heating temperature is 120–180°C and the heating time is 5–15 minutes.

8. The method for preparing a two-dimensional layered amorphous material according to claim 6, characterized in that, In step S3, before peeling off the transfer medium layer, a single layer or few layers of amorphous material are used as the contact surface to retrieve the product obtained in step S2 through the target substrate and dry it.

9. The method for preparing a two-dimensional layered amorphous material according to claim 2, characterized in that, In step S3, the transfer medium layer is dissolved and peeled off.

10. The method for preparing a two-dimensional layered amorphous material according to claim 9, characterized in that, The stripping solvent used is selected from one or both of toluene and acetone.

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