Layer-number-controllable two-dimensional torsional angle MoS2 and preparation method thereof
Multi-layer torsion MoS2 was grown on SiO2/Si substrate by a one-step CVD method, and the reaction conditions were adjusted by sulfur source positioning and regulation method, and the problem of difficulty in preparing multi-layer torsion MoS2 in the prior art was solved, and the preparation of high-quality and controllable layers of multi-layer torsion MoS2 was achieved.
Patent Information
- Application Number
- CN202510110758.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art is difficult to efficiently prepare multi-layer torsion MoS2, especially in the CVD process. The precise synthesis of multi-layer torsion TMDCs faces great difficulty, which makes it very challenging to efficiently prepare multi-layer torsion MoS2.
Multi-layer torsion angle MoS2 is grown on SiO2/Si substrate by using a one-step CVD method. The material torsion nucleation and growth is achieved by finely adjusting reaction conditions such as reaction temperature, reaction time, and heating rate. Thermodynamic equilibrium is broken through the sulfur source positioning and regulation method to reduce the energy required for interlayer torsion.
High-quality preparation of multi-layer torsion MoS2 is achieved, with uniform surface of the material, pollution-free, controllable number of layers, simple process, easy operation, and provides flexibility and designability to adjust the growth rate and nucleation density of the material.
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Figure CN119876898A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of nanomaterials and relates to the preparation of two-dimensional twisted-angle MoS2 with controllable number of layers. Background Art
[0002] In 2018, the paper "Nature, 2018, 556, 43" reported that twisted bilayer graphene can indeed form a moiré flat band structure at the magic angle, and successfully observed some novel physical properties that are not present in the original material. When two sheets of graphene overlap at a twist angle of 1.05°, the bilayer structure exhibits unconventional superconducting behavior. In 2021, the paper "Nature, 2021, 590, 249" reported that when a three-layer graphene structure is constructed and arranged at a twist angle of 1.56°, not only can superconductivity be achieved, but also compared with double-layer "magic angle" graphene, this configuration provides a wider range of twist angle applicability and significantly enhanced electric field tunability. The study published in Science, 2022, 377, 6614 in 2022 further pointed out that as the number of layers increases from three to five, the superconductivity of twisted graphene gradually increases, and finally higher superconducting performance is achieved in multi-layer magic angle graphene. Compared with graphene, transition metal dichalcogenides (TMDCs) have a richer material system, which provides more research platforms for the modulation of moiré superlattices, and the flat band physics associated with twisted angle TMDCs can appear in a wider range of torsion angles (usually less than 5°), which greatly improves the manufacturability and repeatability of the device. As a typical representative of TMDCs, MoS2 exhibits adjustable band gap characteristics related to the number of layers, a uniform surface without dangling bonds, strong spin-orbit coupling, and unique valley degrees of freedom, which make it have a wide range of application potential in optoelectronics, catalysis, and electronic devices. Multilayer twisted MoS2 can also further adjust the electronic structure and enhance the electronic correlation effect, thereby realizing new quantum states (such as strongly correlated insulating states, magnetic states or topological states), providing a new perspective for understanding the physical mechanism of moiré superlattice in different dimensions and material systems. At present, the preparation technology of multilayer twisted MoS2 mainly relies on stacking method and chemical vapor deposition (CVD) method. The stacking method can control the interlayer twist angle and stacking number of the material. However, this method also has some limitations, such as low yield, limited sample size, irregular morphology and unavoidable interlayer contamination, which makes it limited in large-scale production and practical applications. CVD method is widely regarded as an effective method for preparing two-dimensional materials, but CVD technology is currently mainly used in the preparation of double-layer twisted materials. CN114959637A discloses a method for preparing a two-dimensional material twisted MoS2, which successfully prepares a double-layer twisted MoS2 with uniform surface, no pollution and high quality, but does not involve the preparation of multilayer twisted MoS2. Since the CVD process is restricted by many factors, the precise synthesis of multilayer twist-angle TMDCs faces great difficulties, and the efficient preparation of multilayer twist-angle TMDCs remains very challenging.Therefore, this field is in urgent need of a method for preparing multilayer twist-angle materials, which can realize the preparation of multilayer twist-angle materials MoS2 and provide important support for further research on the physical properties of layer-dependent two-dimensional twist-angle materials and exploration of electronic device performance. Summary of the invention
[0003] The present invention provides a two-dimensional twisted-angle MoS2 with controllable number of layers and a preparation method thereof. The experimental process is simple, the raw materials are easy to obtain, and the prepared twisted-angle MoS2 has a clean surface, high quality, and controllable number of layers.
[0004] In order to achieve the above object, the present invention adopts the following technical solutions:
[0005] A method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers, the preparation method comprising:
[0006] Step 1: The preparation space is a closed quartz tube, carrier gas is introduced into both ends of the quartz tube, a quartz crucible is placed at the inflow end of the carrier gas, and sulfur powder is placed in the quartz crucible;
[0007] Step 2: The Si surfaces of two SiO2 / Si substrates are laminated and stacked in a quartz test tube with openings at both ends, and a molybdenum source is placed in the tube, where the molybdenum source is located at the inflow end of the carrier gas;
[0008] Step 3: The quartz test tube and the quartz crucible are both placed in the furnace of the heating furnace, the amount of the sulfur powder is 1.0 to 3.0 g, and the distance that the sulfur powder extends into the furnace is 1.5 to 2.5 cm;
[0009] Step 4: Set the temperature control program, control the heating rate at 25℃ / min, and after the temperature reaches 770-840℃ at a uniform rate, start material growth, and then cool naturally to obtain two-dimensional twist-angle MoS2 with controllable number of layers on the SiO2 / Si substrate.
[0010] Optionally, in the step three, the distance that the sulfur powder extends into the furnace is 2.0 cm; and in the step four, the temperature is raised uniformly to 800° C.
[0011] Optionally, the molybdenum source is a mixture of molybdenum trioxide powder and NaCl particles, the amount of molybdenum trioxide powder is 1-2 mg, and the amount of NaCl particles added is 0.5-1 mg.
[0012] Optionally, the molybdenum source and the sulfur powder are 7 to 12 cm apart.
[0013] Optionally, the SiO2 / Si substrate is 1 cm away from the molybdenum source.
[0014] Optionally, in step 4, before starting heating, purge with Ar at a flow rate of 600 sccm; then adjust the carrier gas flow rate to a constant 40 sccm.
[0015] Optionally, the inner diameter of the quartz test tube is 10 mm;
[0016] The outer diameter of the quartz tube is 25 mm.
[0017] Optionally, the cutting size of the SiO2 / Si substrate is 0.9 cm×3 cm.
[0018] Optionally, the growth time of the chemical vapor deposition is 5 to 10 minutes.
[0019] A two-dimensional twist-angle MoS2 with controllable number of layers is prepared by any preparation method of the two-dimensional twist-angle MoS2 with controllable number of layers described in the present invention.
[0020] Advantages of the present invention:
[0021] (1) This method prepares multilayer twisted-angle MoS2 by a one-step CVD method. The prepared multilayer twisted-angle MoS2 material has a uniform surface, is pollution-free, and has high quality. The preparation process is simple and easy to operate.
[0022] (2) The reaction process can achieve torsional nucleation and growth of materials by finely adjusting reaction conditions such as reaction temperature, reaction time, heating rate, etc., and provides flexibility and designability for the growth rate, nucleation density, etc. of the material.
[0023] (3) During the CVD process, thermodynamics dominates, causing the material to form a thermodynamically stable 3R or 2H structure. We broke the thermodynamic equilibrium by regulating the location of the sulfur source, significantly reducing the energy required for interlayer twisting, which made the twisting of multilayer MoS2 easier, thereby achieving the dynamic growth of multilayer twisted materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:
[0025] Figure 1 It is a schematic diagram of the experimental preparation of the embodiments and comparative examples of the present invention;
[0026] Figure 2 This is an optical microscope photograph of Example 1 of the present invention;
[0027] Figure 3 is the Raman spectrum of Example 1 of the present invention;
[0028] Figure 4 The photoluminescence spectrum of Example 1 of the present invention;
[0029] Figure 5 This is an optical microscope photograph of Example 2 of the present invention;
[0030] Figure 6 is the Raman spectrum of Example 2 of the present invention;
[0031] Figure 7 The photoluminescence spectrum of Example 2 of the present invention;
[0032] Figure 8 This is an optical microscope photograph of Example 3 of the present invention;
[0033] Fig. 9 is the Raman spectrum of Example 3 of the present invention;
[0034] Fig.10 The photoluminescence spectrum of Example 3 of the present invention;
[0035] Fig.11 This is an optical microscope photo of Comparative Example 1 of the present invention;
[0036] Fig.12 This is an optical microscope photograph of Comparative Example 2 in the present invention. DETAILED DESCRIPTION
[0037] The present invention is described in detail below with reference to the accompanying drawings and specific implementation methods.
[0038] The multilayer twisted MoS2 prepared by the present invention achieves the regulation of the number of layers by precisely controlling the temperature and the positioning of the sulfur source; it is grown directly on a SiO2 / Si substrate by chemical vapor deposition. Through the sulfur source positioning regulation method, that is, precisely adjusting the position of the S boat in the single-temperature zone tubular furnace, the amount of the molybdenum source and other factors according to the growth temperature, multilayer twisted MoS2 materials with different numbers of layers are obtained. The higher the temperature, the more layers of twisted MoS2 are produced. The process is simple and the cost is low.
[0039] The two-dimensional twisted-angle MoS2 with controllable number of layers and the preparation method thereof of the present invention realize the regulation of the number of layers by precisely controlling the temperature and the positioning of the sulfur source, and the method steps are as follows:
[0040] Step 1: Place a certain amount of sulfur powder in a quartz crucible, and place the quartz crucible in the heat radiation zone of a single temperature zone tube furnace.
[0041] Step 2: First, place two SiO2 / Si substrates in a quartz test tube with openings at both ends, then place evenly mixed molybdenum source and NaCl at the tube mouth, and place the quartz test tube in the center of a single-temperature zone tubular furnace.
[0042] Step 3: Seal the quartz tube and purge it with Ar at a flow rate of 600 sccm before starting heating. Then adjust the carrier gas flow rate to 40 sccm, and keep it constant during the entire chemical reaction.
[0043] Step 4: Set the temperature control program, control the heating rate at 25℃ / min, and after the temperature reaches 770-840℃ at a uniform rate, carry out material growth, and then cool naturally to obtain multilayer twisted MoS2 on the SiO2 / Si substrate.
[0044] In the embodiments of the present disclosure, the amount of the sulfur source used is 1.0-3.0 g, the distance the sulfur source extends into the furnace is 1.5-2.5 cm, and the corresponding growth temperature is 770-840°C.
[0045] In the embodiment of the present disclosure, the inner diameter of the quartz test tube is 25 mm, the molybdenum source is molybdenum trioxide powder and NaCl particles, the amount of molybdenum trioxide powder is 1-2 mg, and the amount of NaCl particles added is 0.5-1 mg.
[0046] In the embodiment of the present disclosure, a sulfur source is placed in a quartz tube according to the flow direction of the carrier gas, and a quartz test tube with both ends opened is arranged downstream of the sulfur source.
[0047] In the embodiment of the present disclosure, the cutting size of the SiO2 / Si substrate is 0.9 cm×3 cm.
[0048] In the embodiments of the present disclosure, two SiO2 / Si substrates are stacked with their silicon dioxide surfaces facing upward or downward, and a molybdenum source is placed 1 cm in front of the substrates. The molybdenum source is located near the gas inlet of the quartz tube.
[0049] In the embodiments of the present disclosure, the molybdenum source and the sulfur source are 7 to 12 cm apart.
[0050] In the embodiment of the present disclosure, the holding time of chemical vapor deposition is 5 to 10 minutes.
[0051] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, and the advantages of the present invention are reflected by analyzing the comparative examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0052] Embodiment 1:
[0053] The method for preparing a double-layer twisted-angle MoS2 on a silicon dioxide / silicon substrate provided in this embodiment comprises the following steps:
[0054] Step 1: Cut the silica / silicon substrate into 0.9×3 cm sheets and blow them clean with an air gun. Place the silica surfaces back to back in a quartz test tube with openings at both ends and an inner diameter of 10 mm.
[0055] Step 2: Add 1 mg of molybdenum trioxide powder and place it 1 cm from the front of the substrate, and add 1 mg of NaCl to the molybdenum trioxide powder.
[0056] Step 3: Place the quartz test tube in a quartz tube with an outer diameter of 25 mm, add molybdenum trioxide powder and one end of NaCl close to the air inlet. Put 1.2g of sulfur powder into the quartz crucible as the S source, and extend it 2.5cm into the furnace. The S source and the molybdenum source are 10cm apart, and the chemical vapor deposition of the two-dimensional material twisted angle MoS2 is carried out in the center of the tubular atmosphere furnace. Figure 1 shown.
[0057] Step 4: Pass 600 sccm of argon gas for 10 minutes to completely remove the residual oxygen in the tube. Then continue to pass 40 sccm of argon gas, heat the tubular atmosphere furnace to 770℃ at a heating rate of 25℃ / min, and keep it warm for 5 minutes. Then cool it naturally to room temperature. The optical photo of the two-dimensional material MoS2 obtained at this time is as follows Figure 2 shown.
[0058] Depend on Figure 2 Optical photos show that the prepared material is a double-layer twisted MoS2, with the twist angle of the first and second layers being 37°. Figure 3 As shown in Figure 1, both positions 1 and 2 have the Raman characteristic peaks of MoS2, indicating that the prepared material is MoS2. The photoluminescence spectrum of double-layer twisted MoS2 is shown in Figure 1. Figure 4 As shown in the figure, two peaks are observed at 1.81eV and 1.93eV, representing A exciton and B exciton respectively. Among them, the luminescence peak intensity of the single layer is greater than that of the double layer. This shows that the twisted angle structure of the double layer causes the change of the system band structure and causes the photoluminescence intensity to decay.
[0059] Embodiment 2:
[0060] The method for preparing a three-layer twisted-angle MoS2 on a silicon dioxide / silicon substrate provided in this embodiment comprises the following steps:
[0061] Step 1: Cut the silica / silicon substrate into 0.9×3 cm sheets and blow them clean with an air gun. Place the silica surfaces back to back in a quartz test tube with openings at both ends and an inner diameter of 10 mm.
[0062] Step 2: Add 1 mg of molybdenum trioxide powder and place it 1 cm from the front of the substrate, and add 1 mg of NaCl to the molybdenum trioxide powder.
[0063] Step 3: Place the quartz test tube in a quartz tube with an outer diameter of 25 mm, add molybdenum trioxide powder and one end of NaCl close to the air inlet. Put 1.2g of sulfur powder into the quartz crucible as the S source, and extend it 2.0cm into the furnace. The S source and the molybdenum source are 10cm apart, and the chemical vapor deposition of the two-dimensional material twisted angle MoS2 is carried out in the heating center of the tubular atmosphere furnace, such as Figure 1 shown.
[0064] Step 4: Pass 600 sccm of argon gas for 10 minutes to completely remove the residual oxygen in the tube. Then continue to pass 40 sccm of argon gas, heat the tubular atmosphere furnace to 800℃ at a heating rate of 25℃ / min, and keep it warm for 5 minutes. Then cool it naturally to room temperature. The optical photo of the two-dimensional material MoS2 obtained at this time is as follows Figure 5 shown.
[0065] Depend on Figure 5 From the optical photographs, we can see that the prepared material is a three-layer twisted MoS2, with the twist angles of the first and second layers being 100° and the twist angles of the second and third layers being 21°. Figure 6 As shown in Figure 1, positions 1, 2, and 3 all have Raman characteristic peaks of MoS2, indicating that the prepared material is MoS2. The photoluminescence spectrum of the three-layer twisted MoS2 is shown in Figure 1. Figure 7 As shown in the figure, two peaks are observed at 1.81eV and 1.93eV, representing A exciton and B exciton respectively. The A exciton peak is the strongest in a single layer. As the number of layers increases from double layers to triple layers, the position of the A exciton peak moves to lower energy and the intensity gradually increases, while the peak position of the B exciton peak remains unchanged. This indicates that the twist angle structure of the triple layer causes the system band structure to change, showing exciton behavior different from that of the single layer material.
[0066] Embodiment three:
[0067] The method for preparing five-layer twisted-angle MoS2 on a silicon dioxide / silicon substrate provided in this embodiment comprises the following steps:
[0068] Step 1: Cut the silica / silicon substrate into 0.9×3 cm sheets and blow them clean with an air gun. Place the silica surfaces back to back in a quartz test tube with openings at both ends and an inner diameter of 10 mm.
[0069] Step 2: Add 1 mg of molybdenum trioxide powder and place it 1 cm from the front of the substrate, and add 1 mg of NaCl to the molybdenum trioxide powder.
[0070] Step 3: Place the quartz test tube in a quartz tube with an outer diameter of 25 mm, add molybdenum trioxide powder and one end of NaCl close to the air inlet. Put 1.2g of sulfur powder into the quartz crucible as the S source, and extend it 1.5cm into the furnace. The S source and the molybdenum source are 10cm apart, and the chemical vapor deposition of the two-dimensional material twisted angle MoS2 is carried out in the center of the tubular atmosphere furnace. Figure 1 shown.
[0071] Step 4: Pass 600 sccm of argon gas for 10 minutes to completely remove the residual oxygen in the tube. Then continue to pass 40 sccm of argon gas, heat the tubular atmosphere furnace to 840℃ at a heating rate of 25℃ / min, and keep it warm for 5 minutes. Then cool it naturally to room temperature. The optical photo of the two-dimensional material MoS2 obtained at this time is as follows Figure 8 shown.
[0072] Depend on Figure 8 From the optical photos, we can see that the prepared material is a five-layer twisted MoS2, with the twist angles of the first and second layers being 32°, the second and third layers being 65°, the third and fourth layers being 82°, and the fourth and fifth layers being 11°. Fig. 9 As shown in the figure, positions 1, 2, 3, 4, and 5 all have the Raman characteristic peaks of MoS2, indicating that the prepared material is MoS2. The photoluminescence spectrum of the five-layer twisted MoS2 is shown in the figure. Fig.10 As shown in the figure, two peaks are observed at 1.81eV and 1.93eV, representing A exciton and B exciton respectively. The luminescence peak intensity of the single layer is greater than that of the two, three, four, and five layers. As the number of layers increases from two layers to five layers, the position of the A exciton peak gradually moves to lower energy. This indicates that the twist angle structure causes the system band structure to change and causes the photoluminescence intensity to decay.
[0073] Comparative Example 1:
[0074] The method for preparing two-dimensional MoS2 material by increasing the temperature without adjusting the position of the S source provided in this comparative example comprises the following steps:
[0075] Step 1: Cut the silica / silicon substrate into 0.9×3 cm sheets and blow them clean with an air gun. Place the silica surfaces back to back in a quartz test tube with openings at both ends and an inner diameter of 10 mm.
[0076] Step 2: Add 1 mg of molybdenum trioxide powder and place it 1 cm from the front of the substrate, and add 1 mg of NaCl to the molybdenum trioxide powder.
[0077] Step 3: Place the quartz test tube in a quartz tube with an outer diameter of 25 mm, add molybdenum trioxide powder and one end of NaCl close to the air inlet. Put 1.2g of sulfur powder into the quartz crucible as the S source, and extend it 2.6cm into the furnace. The S source and the molybdenum source are 10cm apart, and the chemical vapor deposition of the two-dimensional material twisted angle MoS2 is carried out in the center of the tubular atmosphere furnace. Figure 1 shown.
[0078] Step 4: Same as Example 2, the optical photo of MoS2 obtained at this time is as follows Fig.11 shown.
[0079] Compared with Example 2, it can be seen that the position of the S source is not adjusted and only the temperature is increased to prepare the two-dimensional MoS2 material. When other conditions remain unchanged, the material prepared on the substrate is an ultra-multilayer irregularly shaped non-twisted MoS2.
[0080] Comparative Example 2:
[0081] The method for preparing two-dimensional MoS2 material by adjusting the position of the S source without increasing the temperature given in this comparative example comprises the following steps:
[0082] Step 1: Cut the silica / silicon substrate into 0.9×3 cm sheets and blow them clean with an air gun. Place the silica surfaces back to back in a quartz test tube with openings at both ends and an inner diameter of 10 mm.
[0083] Step 2: Add 1 mg of molybdenum trioxide powder and place it 1 cm from the front of the substrate, and add 1 mg of NaCl to the molybdenum trioxide powder.
[0084] Step 3: Same as Example 2.
[0085] Step 4: Pass 600 sccm of argon gas for 10 minutes to completely remove the residual oxygen in the tube. Then continue to pass 40 sccm of argon gas, heat the tubular atmosphere furnace to 860℃ at a heating rate of 25℃ / min, and keep it warm for 5 minutes. Then cool it naturally to room temperature. The optical photo of MoS2 obtained at this time is as follows Fig.12 shown.
[0086] Compared with Example 2, it can be seen that the two-dimensional MoS2 material is prepared by adjusting the position of the S source without increasing the temperature. When other conditions remain unchanged, the material prepared on the substrate is an ultra-multilayer irregularly shaped non-twisted MoS2.
[0087] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers, characterized in that: The preparation method comprises: Step 1: The preparation space is a closed quartz tube, carrier gas is introduced into both ends of the quartz tube, a quartz crucible is placed at the inflow end of the carrier gas, and sulfur powder is placed in the quartz crucible; Step 2: The Si surfaces of two SiO2 / Si substrates are laminated and stacked in a quartz test tube with openings at both ends, and a molybdenum source is placed in the tube, where the molybdenum source is located at the inflow end of the carrier gas; Step 3: The quartz test tube and the quartz crucible are both placed in the furnace of the heating furnace, the amount of the sulfur powder is 1.0 to 3.0 g, and the distance that the sulfur powder extends into the furnace is 1.5 to 2.5 cm; Step 4: Set the temperature control program, control the heating rate at 25℃ / min, and after the temperature reaches 770-840℃ at a uniform rate, start material growth, and then cool naturally to obtain two-dimensional twist-angle MoS2 with controllable number of layers on the SiO2 / Si substrate.
2. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1, characterized in that: In the step 3, the distance that the sulfur powder extends into the furnace is 2.0 cm; In the step 4, the temperature is raised uniformly to 800°C.
3. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The molybdenum source is a mixture of molybdenum trioxide powder and NaCl particles, the amount of molybdenum trioxide powder is 1-2 mg, and the amount of NaCl particles added is 0.5-1 mg.
4. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The molybdenum source and the sulfur powder are 7 to 12 cm apart.
5. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The SiO2 / Si substrate is 1 cm away from the molybdenum source.
6. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: In the fourth step, before starting heating, purge with Ar at a flow rate of 600 sccm; then adjust the carrier gas flow rate to a constant 40 sccm.
7. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The inner diameter of the quartz test tube is 10 mm; The outer diameter of the quartz tube is 25 mm.
8. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The cutting size of the SiO2 / Si substrate is 0.9 cm×3 cm.
9. The method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers according to claim 1 or 2, characterized in that: The growth time of the chemical vapor deposition is 5 to 10 minutes.
10. A two-dimensional twisted-angle MoS2 with controllable number of layers, characterized in that: It is prepared by the method for preparing two-dimensional twisted-angle MoS2 with controllable number of layers as described in any one of claims 1-9.