Preparation method of MoS2 film
By using water as a solvent, surfactant, and supersaturated molybdenum source to prepare MoS2 thin films, combined with plasma treatment and laser irradiation, the problems of high cost and poor quality in MoS2 thin film preparation have been solved, achieving efficient and environmentally friendly thin film preparation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2026-03-17
AI Technical Summary
Existing methods for preparing MoS2 thin films suffer from problems such as complex processes, high costs, environmental unfriendliness, and poor film quality.
MoS2 thin films were prepared by using water as a solvent, adding surfactants and supersaturated ammonium tetrathiomolybdate as molybdenum and sulfur sources, and combining plasma treatment and laser irradiation technology.
This method enables the preparation of high-quality MoS2 thin films at low cost and in an environmentally friendly manner, simplifies the process, improves the crystallinity and continuity of the films, and reduces defects.
Smart Images
Figure CN121672584A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor thin film materials technology, and more specifically, relates to a method for preparing MoS2 thin films. Background Technology
[0002] Molybdenum disulfide (MoS2), a typical transition metal sulfide, exhibits great application potential in catalysis, energy storage, and photoelectric conversion due to its unique layered structure and excellent physicochemical properties. For example, in catalysis, its abundant active sites enable it to efficiently catalyze various chemical reactions; in energy storage, it can serve as a high-performance electrode material to improve battery charge-discharge performance. However, traditional preparation methods have limitations. Currently, the mainstream preparation methods include chemical vapor deposition (CVD), mechanical exfoliation, and liquid phase exfoliation. These methods generally suffer from the following problems: high process complexity. CVD requires high temperatures (600~1000℃) and a precise gas control system, limiting the application of flexible substrates; mechanical exfoliation relies on manual operation, making it difficult to achieve mass production of large-area uniform films. A trade-off between material quality and cost; while liquid phase exfoliation can be scaled up, it easily introduces solvent residues and structural defects, leading to a decline in the electrical performance of the film; high-purity MoS2 precursors are expensive, further increasing production costs. Insufficient environmental friendliness; some methods require the use of toxic organic solvents (such as NMP and DMF), posing a risk of environmental pollution. Therefore, there is an urgent need to develop a simple, low-cost, and environmentally friendly MoS2 thin film preparation technology. Summary of the Invention
[0003] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a method for preparing MoS2 thin films, thereby solving the technical problems of high cost and complex process in the preparation of MoS2 thin films in the prior art.
[0004] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a MoS2 thin film is provided, specifically comprising the following steps: (1) Mix water, molybdenum source, sulfur source and surfactant evenly to obtain precursor solution; (2) The substrate is subjected to plasma treatment, and then the precursor solution is coated on the substrate and the coating is dried. (3) The coating layer is irradiated with a laser beam to form a MoS2 thin film.
[0005] Preferably, the molybdenum source and the sulfur source are both selected from ammonium tetrathiomolybdate.
[0006] Preferably, the mass ratio of the ammonium tetrathiomolybdate to the volume ratio of water in the precursor solution is 10 mg / ml - 100 mg / ml.
[0007] Preferably, the molar ratio of the ammonium tetrathiomolybdate to the surfactant is 10000:(1-10).
[0008] Preferably, the surfactant is selected from one or more of Triton X-100, fatty alcohol polyoxyethylene ether, and polyoxyethylene lauryl ether.
[0009] Preferably, the mass ratio of the surfactant to the volume ratio of water in the precursor solution is 0.001-0.1 mg / ml.
[0010] Preferably, the substrate is selected from silicon wafers, sapphire, silicon carbide, gallium arsenide, gallium nitride, or silicon carbide.
[0011] Preferably, the plasma treatment is specifically oxygen plasma treatment; the flow rate of the oxygen plasma is 10-100 sccm, and the plasma treatment time is 5-10 min.
[0012] Preferably, the coating is performed by spin coating using a spin coater with a rotation speed of 500-4000 r / min and a spin coating time of 20-30 s.
[0013] Preferably, the drying temperature is 80-200℃ and the drying time is 1-10 minutes.
[0014] Preferably, the energy density of the laser beam is 30-50 mJ / cm². 2 The number of laser radiation pulses is 100-2000.
[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: (1) The purpose of adding a surfactant to the precursor solution in this invention is to increase the adhesion of the precursor solution to the substrate. This invention uses water as the liquid precursor solvent. Water is a non-toxic, harmless and low-cost solvent. Compared with the prior art which uses organic solvents as the solvents for molybdenum and sulfur sources, organic solvents will leave organic residues after subsequent laser irradiation treatment, which will affect the film quality and device performance. Therefore, this invention uses water as the solvent, which can further improve the quality of the MoS2 film. This invention performs plasma treatment on the substrate to increase the hydrophilicity of the substrate, thereby increasing the adhesion of the liquid precursor solution to the substrate, so that the precursor solution can be smoothly spin-coated onto the substrate. In addition, due to the increase in hydrophilicity of the substrate by plasma treatment, the precursor solution with water as the solvent can adhere better to the substrate. The purpose of using laser irradiation in this invention is to cause the precursor on the substrate to undergo a photochemical reaction to generate molybdenum disulfide, thereby preparing a molybdenum disulfide film.
[0016] (2) The present invention limits the mass ratio of the ammonium tetrathiomolybdate to the volume ratio of water in the precursor solution to 10 mg / ml - 100 mg / ml. Within this concentration range, the ammonium tetrathiomolybdate is a supersaturated solution. The purpose of selecting supersaturated ammonium tetrathiomolybdate as the molybdenum source and sulfur source is to avoid excessive growth of individual crystal nuclei due to the high nucleation density of the supersaturated solution, so that the crystal nuclei are evenly distributed and eventually fused to form a continuous film. Moreover, the concentration gradient of the solute in the supersaturated solution is much greater than that in the unsaturated solution, and the diffusion rate of the solute to the surface of the crystal nucleus is faster. Rapid diffusion can replenish the solute required for crystal nucleus growth in time, and avoid growth interruption (such as defects such as pores and cracks) due to insufficient solute supply. At the same time, the atoms are more tightly arranged in a high concentration environment, and the atomic stacking is more orderly during crystal nucleus growth, which is beneficial to reduce vacancies or dislocation defects inside the film.
[0017] (3) The preparation process of the present invention is simple, has a high reproducibility, and does not involve any toxic substances in the reaction. It can achieve the controllable deposition of high-quality MoS2 thin films under mild conditions. Attached Figure Description
[0018] Figure 1 This is a process flow diagram for preparing molybdenum disulfide provided in an embodiment of the present invention.
[0019] Figure 2 This is an optical microscope image of the molybdenum disulfide thin film prepared using this method, provided in Example 3 of the present invention.
[0020] Figure 3 These are Raman characterization images of MoS2 thin films prepared with different concentrations of precursors provided in the embodiments of the present invention; wherein (a) is the precursor solution prepared in Example 1 with 1 mg / ml ammonium tetrathiomolybdate solution and 0.001 mg / L Triton X-100; (b) is the precursor solution prepared in Example 2 with 10 mg / ml ammonium tetrathiomolybdate solution and 0.01 mg / L Triton X-100; and (c) is the precursor solution prepared in Example 3 with 100 mg / ml ammonium tetrathiomolybdate solution and 0.1 mg / L Triton X-100.
[0021] Figure 4 Optical microscope image of the molybdenum disulfide thin film prepared for Comparative Example 1.
[0022] Figure 5 The image shows the Raman characterization of the molybdenum disulfide thin film prepared in Comparative Example 1.
[0023] Figure 6 Optical microscope image of the molybdenum disulfide thin film prepared for Comparative Example 2.
[0024] Figure 7 Raman characterization of the molybdenum disulfide thin film prepared for Comparative Example 2. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0026] Example 1 This invention provides a method for preparing MoS2 thin films, specifically including the following steps: (Detailed process follows) Figure 1 As shown: (1) Preparation of precursor solution: Add 10 ml of deionized water, 10 mg of ammonium tetrathiomolybdate powder, and 0.01 mg of Triton X-100 to a flask. Place the flask in a water bath at 30 °C and stir magnetically at 1000 r / min for 2 h. Then, sonicate for 10 min at a power of 1000 W. Finally, filter the precursor solution to remove insoluble solid particles.
[0027] (2) Select a silicon wafer as the substrate. The size of the silicon wafer is 10mm×15mm. There is a silicon dioxide oxide layer with a thickness of 100nm on it. Clean and dry the silicon wafer.
[0028] (3) The substrate was subjected to oxygen plasma treatment with an oxygen flow rate of 50 sccm and a treatment time of 15 min.
[0029] (4) Spin-coat the precursor solution onto the substrate at 500 r / min for 5 s, and then spin-coat at 2000 r / min for 25 s.
[0030] (5) Place the spin-coated substrate on a baking plate and heat at 100°C for 5 minutes.
[0031] (6) Place the spin-coated and dried substrate inside the laser cavity and apply 35 mJ / cm². 2 The laser irradiates the substrate, and the number of laser irradiation pulses is 100.
[0032] The obtained MoS2 thin film was Raman characterized, and the results are as follows: Figure 3 As shown in (a).
[0033] Example 2 This invention provides a method for preparing MoS2 thin films, specifically including the following steps: (1) Preparation of precursor solution: Add 10 ml of deionized water, 100 mg of ammonium tetrathiomolybdate powder, and 0.1 mg of Triton X-100 to a flask, place it in a water bath at 30 °C, and stir magnetically at 1000 r / min for 2 h. Then, sonicate for 10 min at a power of 1000 W.
[0034] (2) Select a silicon wafer as the substrate. The size of the silicon wafer is 10mm×15mm. There is a silicon dioxide oxide layer with a thickness of 100nm on it. Clean and dry the silicon wafer.
[0035] (3) The substrate was subjected to oxygen plasma treatment with an oxygen flow rate of 50 sccm and a treatment time of 15 min.
[0036] (4) Spin-coat the precursor onto the substrate at 500 r / min for 5 s, and then spin-coat at 2000 r / min for 25 s.
[0037] (5) Place the spin-coated substrate on a baking plate and heat at 100°C for 5 minutes.
[0038] (6) Place the spin-coated and dried substrate inside the laser cavity and apply 35 mJ / cm². 2 The laser irradiates the substrate with 100 pulses.
[0039] The obtained MoS2 thin film was Raman characterized, and the results are as follows: Figure 3 As shown in (b).
[0040] Example 3 This invention provides a method for preparing MoS2 thin films, specifically including the following steps: (1) Preparation of precursor solution: Add 1 ml of deionized water, 100 mg of ammonium tetrathiomolybdate powder, and 0.1 mg of Triton X-100 to a flask, place it in a water bath at 30 °C, and stir magnetically at 1000 r / min for 2 h. Then, sonicate for 10 min at a power of 1000 W.
[0041] (2) Select a silicon wafer as the substrate. The size of the silicon wafer is 10mm×15mm. There is a silicon dioxide oxide layer with a thickness of 100nm on it. Clean and dry the silicon wafer.
[0042] (3) The substrate was subjected to oxygen plasma treatment with an oxygen flow rate of 50 sccm and a treatment time of 15 min.
[0043] (4) Spin-coat the precursor onto the substrate at 500 r / min for 5 s, and then spin-coat at 2000 r / min for 25 s.
[0044] (5) Place the spin-coated substrate on a baking plate and heat at 100°C for 5 minutes.
[0045] (6) Place the spin-coated and dried substrate inside the laser cavity and apply 35 mJ / cm². 2 The laser irradiates the substrate with 100 pulses.
[0046] The obtained MoS2 thin film was Raman characterized, and the results are as follows: Figure 3 As shown in (c).
[0047] Depend on Figure 3 As can be seen in the Raman diagrams shown in (b) and (c), E2g 1 Peak (located at 383cm) -1 (near) and A1g peak (approximately 408 cm) -1 The half-peak width (in the vicinity) compared to Figure 3 The number of impurity peaks is significantly reduced in (a), and the peak intensity is increased. The Raman curve is smoother, and the number of impurity peaks is reduced. This indicates that the molybdenum disulfide film prepared using supersaturated ammonium tetrathiomolybdate solution has higher crystallinity and better film continuity and quality compared with the molybdenum disulfide film prepared using unsaturated ammonium tetrathiomolybdate solution.
[0048] Comparative Example 1 This invention provides a method for preparing MoS2 thin films, specifically including the following steps: (1) Preparation of precursor solution: Add 2 ml isopropanol, 1.5 ml ethylene glycol, 10 mg ammonium tetrathiomolybdate powder, and 0.1 mg Triton X-100 to a flask, place it in a water bath at 30 °C, and stir magnetically at 1000 r / min for 2 h. Then, sonicate for 10 min at a power of 1000 W.
[0049] (2) Select a silicon wafer as the substrate. The size of the silicon wafer is 10mm×15mm. There is a silicon dioxide oxide layer with a thickness of 100nm on it. Clean and dry the silicon wafer.
[0050] (3) The substrate was subjected to oxygen plasma treatment with an oxygen flow rate of 50 sccm and a treatment time of 15 min.
[0051] (4) Spin-coat the precursor onto the substrate at 500 r / min for 5 s, and then spin-coat at 2000 r / min for 25 s.
[0052] (5) Place the spin-coated substrate on a baking plate and heat at 100°C for 5 minutes.
[0053] (6) Place the spin-coated and dried substrate inside the laser cavity and apply 35 mJ / cm². 2The substrate was irradiated with a laser with 100 pulses. The optical image of the MoS2 thin film obtained in Comparative Example 1 is shown below. Figure 4 As shown, by Figure 4 It can be seen that residual organic matter (black patches) on the film greatly affects the film's continuity; the Raman diagram is shown below. Figure 5 As shown, by Figure 5 It can be seen that the Raman spectrum peak intensity is relatively small and the half-peak width is larger, indicating that the film quality is poor.
[0054] Comparative Example 2 This invention provides a method for preparing MoS2 thin films, specifically including the following steps: (1) Preparation of precursor solution: Add 1 ml of deionized water and 100 mg of ammonium tetrathiomolybdate powder to a flask, place it in a water bath at 30 °C, and stir magnetically at 1000 r / min for 2 h. Then, sonicate for 10 min at a power of 1000 W.
[0055] (2) Select a silicon wafer as the substrate. The size of the silicon wafer is 10mm×15mm. There is a silicon dioxide oxide layer with a thickness of 100nm on it. Clean and dry the silicon wafer.
[0056] (3) The substrate was subjected to oxygen plasma treatment with an oxygen flow rate of 50 sccm and a treatment time of 15 min.
[0057] (4) Spin-coat the precursor onto the substrate at 500 r / min for 5 s, and then spin-coat at 2000 r / min for 25 s.
[0058] (5) Place the spin-coated substrate on a baking plate and heat at 100°C for 5 minutes.
[0059] (6) Place the spin-coated and dried substrate inside the laser cavity and apply 35 mJ / cm². 2 The laser irradiates the substrate with 100 pulses.
[0060] The thin film optical imaging obtained in Comparative Example 2 is shown below. Figure 6 As shown, by Figure 6 As can be seen, the deionized water on the surface is widely dispersed and does not form a continuous film, indicating that the spin coating was not successful; the Raman diagram is shown below. Figure 7 As shown, by Figure 7 As can be seen, Raman spectroscopy showed that no molybdenum disulfide film was formed.
[0061] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for producing a MoS2 thin film, characterized by, The method comprises the following steps: (1) mixing water, a molybdenum source, a sulfur source and a surfactant uniformly to obtain a precursor solution; (2) performing plasma treatment on a substrate, then coating the precursor solution on the substrate, and drying the coating layer; (3) radiating the coating layer with a laser beam to form a MoS2 film on the coating layer.
2. The method of claim 1, wherein the MoS2 thin film is prepared by a method comprising: The molybdenum source and the sulfur source are both selected from ammonium tetrathiomolybdate.
3. A method of producing a MoS2 film according to claim 2, wherein The mass of the ammonium tetrathiomolybdate to the volume of water in the precursor solution is 10 mg / ml - 100 mg / ml.
4. The method of claim 3, wherein the MoS2 thin film is prepared by a method comprising: The molar ratio of the ammonium tetrathiomolybdate to the surfactant is 10000: (1-10).
5. The method for preparing a MoS2 thin film as described in claim 1, characterized in that, The surfactant is selected from one or more of Triton X-100, fatty alcohol polyoxyethylene ether and polyoxyethylene lauryl ether; The mass of the surfactant to the volume of water in the precursor solution is 0.001-0.1 mg / ml.
6. The method for preparing a MoS2 thin film as described in claim 1, characterized in that, The substrate is selected from a silicon wafer, sapphire, silicon carbide, gallium arsenide, gallium nitride or silicon carbide.
7. The method for preparing a MoS2 thin film as described in claim 1, characterized in that, The plasma treatment is specifically oxygen plasma treatment; the flow rate of the oxygen plasma is 10-100 sccm, and the plasma treatment time is 5-10 min.
8. The method of claim 1, wherein the MoS2 thin film is prepared by a process comprising: The coating is specifically performed by spin coating with a spin coater, and the rotation speed of the spin coater is 500-4000 r / min, and the spin coating time is 20-30 s.
9. The method for preparing a MoS2 thin film as described in claim 1, characterized in that, The drying temperature is 80-200 ℃, and the drying time is 1-10 min.
10. The method for preparing a MoS2 thin film as described in claim 1, characterized in that, The energy density of the laser beam is 30-50 mJ / cm 2 The number of laser radiation pulses is 100-2000.