Preparation method of molybdenum disulfide / diamond heterostructure
By preparing molybdenum disulfide films using ultrasonic cleaning and MPCVD on diamond substrates, the problems of interfacial carbide pollution, poor process compatibility, and thermal stress mismatch in the prior art are solved, and a high-quality molybdenum disulfide/diamond heterostructure is achieved.
Patent Information
- Application Number
- CN202510408384.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-06-27
AI Technical Summary
The prior art faces problems such as interfacial carbide pollution, poor process compatibility, and thermal stress mismatch when preparing molybdenum disulfide heterostructure on diamond substrates.
Ultrasonic cleaning method was used to remove impurities on the surface of diamond substrate, and a molybdenum disulfide film was prepared on the boron-doped diamond surface by MPCVD method, and carbide-free generation and high interface quality were achieved through single-zone vulcanization deposition.
It effectively solves the problems of interfacial carbide pollution, poor process compatibility, and thermal stress mismatch, ensures the optimization of interface chemical purity and thermodynamic parameters, and improves the overall performance of heterostructure.
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Figure CN120210764A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of semiconductor technology, and more specifically, relates to a method for preparing a molybdenum disulfide / diamond heterostructure. Background Art
[0002] In recent years, the hetero-integration of two-dimensional materials and ultra-wide bandgap semiconductor materials has become an important direction for the research and development of new electronic devices. Among them, molybdenum disulfide, as a typical transition metal sulfide, has a high specific surface area, outstanding electronic properties, and excellent mechanical properties. Molybdenum disulfide (MoS2), as a typical transition metal chalcogenide (TMDCs), shows potential in fields such as transistors and photodetectors due to its unique layered structure, tunable bandgap (1.2 - 1.8 eV), and high carrier mobility. Diamond, as an ultra-wide bandgap semiconductor (bandgap 5.47 eV), has extremely high thermal conductivity (2000 W / m▪K), breakdown field strength (10 MV / cm), and carrier mobility, and is regarded as an ideal substrate material for next-generation high-power and high-frequency devices. The heterostructure formed by combining molybdenum disulfide and diamond can synergistically combine their physical properties, providing a new platform for the development of high-frequency and high-voltage devices, quantum sensors, and extreme environment electronic systems.
[0003] However, the existing technology faces significant challenges in preparing molybdenum disulfide heterostructures on diamond substrates, such as interfacial carbide contamination, poor process compatibility, and thermal stress mismatch. Therefore, there is an urgent need to develop a method for preparing molybdenum disulfide / diamond heterostructures without carbide formation, with high interface quality, and strong process compatibility. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for preparing a molybdenum disulfide / diamond heterostructure, aiming to solve the technical problems of interfacial carbide contamination, poor process compatibility, and thermal stress mismatch in the preparation of molybdenum disulfide heterostructures on diamond substrates in the existing technology.
[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a method for preparing a molybdenum disulfide / diamond heterostructure, including the following steps: Step 1, ultrasonically clean the diamond substrate using an organic solvent to remove impurity contamination on the surface of the diamond substrate and improve the purity of material growth; Step 2, place the cleaned diamond substrate into the MPCVD chamber, select a suitable heat-dissipating molybdenum holder, and place the diamond substrate at the central position of the heat-dissipating molybdenum holder; Step 3: Close the MPCVD chamber. Use a mechanical pump and a molecular pump to evacuate the MPCVD chamber. When the vacuum degree in the MPCVD chamber is pumped down to below 1E-6 mbar, start the process. Introduce 188 sccm of hydrogen into the MPCVD chamber. After waiting for the pressure in the MPCVD chamber to reach 25 mbar, turn on the microwave source to introduce microwaves for ignition. After the MPCVD chamber is heated to 900 °C, introduce 10 sccm of methane and 2 sccm of borane-hydrogen mixture, and control the temperature for growth for 15 minutes. Step 4: After the growth is completed, close the borane-hydrogen mixture and methane. Alternately reduce the pressure and power in the MPCVD chamber to cool down. Then close the hydrogen, evacuate the MPCVD chamber to below 1E-6 mbar, fill it with nitrogen, and take out the diamond substrate sample. Step 5: Use a mixed solution of concentrated sulfuric acid / concentrated nitric acid to clean the grown boron-doped diamond sample at high temperature to remove the residual non-diamond phase during the growth process. Step 6: Deposit a molybdenum film on the diamond surface by evaporation coating. Step 7: Put the diamond substrate and sulfur powder into the reaction chamber of a single-zone furnace. Close the reaction chamber and evacuate it to below 1E-6 mbar to remove air and impurities and prevent unnecessary oxidation reactions during the reaction. Gradually increase the temperature of the single-zone furnace according to the gradient heating program. First, raise the temperature to 800 °C and keep it warm for 10 minutes. Then raise the temperature to 900 °C to sublime the sulfur powder to form sulfur vapor. The sulfur vapor pressure is 10 - 50 Pa. The sulfur vapor reacts with the molybdenum film deposited on the diamond substrate. The sulfidation temperature is 800 - 950 °C, and a molybdenum disulfide thin film is grown on the diamond surface; an n-MoS2 / P-diamond heterostructure is obtained. Step 8: Characterize the MoS2 thin film using a Raman spectrometer. The Raman characteristic peak positions are at E 1 2g 383 cm -1 , A 1g 404.5 cm -1 and the difference between the two characteristic peaks is 21.5 cm -1 .
[0006] In a possible implementation, in Step 1, the organic solvent is one of acetone and absolute ethanol.
[0007] In a possible implementation, in Step 3, the microwave input power is 2000 W, and the ratio of borane / hydrogen in the unit volume of the borane-hydrogen mixture is 1 / 10000.
[0008] In a possible implementation, in step six, molybdenum is used as the evaporation material. After it is made into a shape matching the surface shape of the diamond, it is placed in the crucible of the evaporation stage. The boron-doped diamond sample is fixed on the substrate holder and placed in the vacuum coating chamber. The vacuum system is started to pump the vacuum to below 1E-6 mbar. The electron beam heating method is selected to evaporate molybdenum. The molybdenum vapor moves in the vacuum environment and condenses on the diamond surface, and finally a molybdenum film is formed.
[0009] In a possible implementation, the thickness of the molybdenum film formed in step six is 1 - 5 nm. After the coating is completed, the heating source is turned off, and the vacuum coating chamber is allowed to cool naturally. After cooling to room temperature, the diamond sample is taken out.
[0010] In a possible implementation, in step seven, the sulfidation time is 30 - 120 min, and the sulfidation time is reasonably selected or adjusted according to the thickness of the molybdenum film; after the growth is completed, the temperature in the single-zone furnace reaction chamber is slowly decreased to room temperature, and the temperature drop rate is ≤5 °C / min. After the temperature drop is completed, argon is introduced into the reaction chamber, and the reaction chamber is opened to obtain the n-MoS2 / P-diamond heterostructure.
[0011] In a possible implementation, in step seven, the sulfidation time is 60 min, and the temperature drop rate is 3 °C / min.
[0012] In a possible implementation, in step eight, the difference between the two characteristic peaks of bulk molybdenum disulfide is 21.5 cm -1 , as the number of layers of molybdenum disulfide decreases, the two characteristic peaks will shift, and the difference gradually becomes smaller. The difference between the characteristic peaks corresponding to monolayer MoS2 is 19 cm -1 .
[0013] In a possible implementation, in step seven, 2 - 3 layers of molybdenum disulfide thin films are prepared on the diamond substrate.
[0014] In a possible implementation, in step seven, the sulfur vapor pressure is 30 Pa, and the sulfidation temperature is 900 °C.
[0015] The beneficial effects of a method for preparing a molybdenum disulfide / diamond heterostructure provided by the present invention are as follows: Compared with the prior art, the method for preparing a molybdenum disulfide / diamond heterostructure of the present invention includes preparing boron-doped single-crystal diamond using the MPCVD method, preparing a molybdenum disulfide thin film on the surface of boron-doped diamond using the single-zone sulfurization deposition method to obtain an n-MoS2 / P-diamond heterostructure, and characterizing the MoS2 thin film using a Raman spectrometer. The present invention solves the technical problems of interface carbide pollution, poor process compatibility, and thermal stress mismatch when preparing a molybdenum disulfide heterostructure on a diamond substrate, effectively combines the performance advantages of molybdenum disulfide and diamond materials, and has the technical effects of avoiding transfer process defects, ensuring interface chemical purity, optimizing thermodynamic parameters, and alleviating the thermal stress mismatch problem of the heterostructure. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0017] Figure 1 It is a step block diagram of a method for preparing a molybdenum disulfide / diamond heterostructure provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a method for preparing a molybdenum disulfide / diamond heterostructure provided by an embodiment of the present invention; Figure 3 It is a spectrogram generated by a Raman spectrometer of the molybdenum disulfide layer material of a method for preparing a molybdenum disulfide / diamond heterostructure provided by an embodiment of the present invention.
[0018] Description of the reference numerals: 1. Diamond substrate; 2. Boron-doped diamond; 3. Molybdenum disulfide thin film. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention clearer, the following further describes the present invention in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0020] Please refer to Figures 1 to 3 together, and now a method for preparing a molybdenum disulfide / diamond heterostructure provided by the present invention will be described. The method for preparing a molybdenum disulfide / diamond heterostructure includes the following steps: Step 1: Use an organic solvent to ultrasonically clean the diamond substrate 1 to remove impurity contamination on the surface of the diamond substrate 1 and improve the purity of material growth; Step 2: Place the cleaned diamond substrate 1 into the MPCVD chamber, select a suitable heat-dissipating molybdenum carrier, and place the diamond substrate 1 at the central position of the heat-dissipating molybdenum carrier; Step 3: Close the MPCVD chamber, use a mechanical pump and a molecular pump to evacuate the MPCVD chamber respectively. After the vacuum degree in the MPCVD chamber is pumped down to below 1E-6 mbar, start the process. Introduce hydrogen at 188 sccm into the MPCVD chamber. After waiting for the pressure in the MPCVD chamber to reach 25 mbar, turn on the microwave source to introduce microwaves for ignition. After the MPCVD chamber is heated to 900 °C, introduce methane at 10 sccm and a boron hydride-hydrogen mixed gas at 2 sccm, and control the temperature for growth for 15 min; Step 4: After growth is completed, turn off the boron hydride-hydrogen mixed gas and methane, alternately reduce the pressure and power in the MPCVD chamber to cool down, turn off hydrogen, evacuate the MPCVD chamber to below 1E-6 mbar, fill it with nitrogen, and take out the diamond substrate 1 sample; Step 5: Use a concentrated sulfuric acid / concentrated nitric acid mixed solution to clean the grown boron-doped diamond 2 sample at high temperature to remove the non-diamond phase residues during growth; Step 6: Deposit a molybdenum film on the diamond surface by evaporation coating; Step 7: Put the diamond substrate 1 and sulfur powder into the reaction chamber of a single-zone furnace. Close the reaction chamber, evacuate the reaction chamber to below 1E-6 mbar to discharge air and impurities to prevent unnecessary oxidation reactions during the reaction. Gradually increase the temperature of the single-zone furnace according to the gradient heating program. First, raise it to 800 °C and keep it warm for 10 min, then raise the temperature to 900 °C to sublime the sulfur powder to form sulfur vapor. The sulfur vapor pressure is 10 - 50 Pa, and the sulfur vapor reacts with the molybdenum film deposited on the diamond substrate 1. The sulfidation temperature is 800 - 950 °C, and a molybdenum disulfide thin film 3 grows on the diamond surface; an n-MoS2 / P-diamond heterostructure is obtained; Step 8: Characterize the MoS2 thin film using a Raman spectrometer. The Raman characteristic peak positions are at E 1 2g 383 cm -1 , A 1g 404.5 cm -1 , and the difference between the two characteristic peaks is 21.5 cm -1 .
[0021] A method for preparing a molybdenum disulfide / diamond heterostructure provided by the present invention, compared with the prior art, includes preparing boron-doped single-crystal diamond using the MPCVD method, and preparing a molybdenum disulfide thin film 3 on the surface of the boron-doped diamond 2 using a single-zone sulfurization deposition method to obtain an n-MoS2 / P-diamond heterostructure, and characterizing the MoS2 thin film using a Raman spectrometer. The method for preparing a molybdenum disulfide / diamond heterostructure provided by the present invention solves the technical problems of interfacial carbide contamination, poor process compatibility, and thermal stress mismatch when preparing a molybdenum disulfide heterostructure on a diamond substrate 1, effectively combines the performance advantages of molybdenum disulfide and diamond materials, and has the technical effects of avoiding transfer process defects, ensuring interfacial chemical purity, optimizing thermodynamic parameters, and alleviating the thermal stress mismatch problem of the heterostructure.
[0022] The technical problem to be solved by the present invention is to sequentially prepare boron-doped single-crystal diamond and a molybdenum disulfide thin film 3 using a chemical vapor deposition (CVD) method, which has good rectifying and ultraviolet photoconductive characteristics and is applied to the semiconductor field. A molybdenum susceptor is a component used to support and fix materials in high-temperature and high-vacuum environments, and is commonly used in processes such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). The molybdenum susceptor is usually made of pure molybdenum or a molybdenum alloy, has a high melting point, high thermal conductivity, and good chemical stability, and is suitable for application scenarios that require high stability and high thermal conductivity. In the microwave plasma chemical vapor deposition (MPCVD) process, the molybdenum susceptor is also used to support the diamond substrate 1. The molybdenum susceptor is used for support and heat dissipation in the manufacture of electronic devices, especially in situations that require high thermal conductivity and high stability.
[0023] In some embodiments, please refer to Figures 1 to 3 , in step one, the organic solvent is one of acetone, absolute ethanol (or 99.9% ethanol), and deionized water, and other organic solvents can also be used to ultrasonically clean the diamond substrate 1. The cleaning time using acetone is 10 minutes, the cleaning time using ethanol is 8 minutes, and the cleaning time using deionized water is 5 minutes.
[0024] In step two, select a molybdenum susceptor with a heat dissipation function. The material purity of the molybdenum susceptor is 99.9%, the surface is finely polished, and the roughness is less than 0.1 μm. Wipe the heat dissipation molybdenum susceptor with alcohol to remove possible oil stains and dust on the surface.
[0025] Open the hatch of the MPCVD chamber and gently place the prepared heat-dissipating molybdenum carrier on the sample stage inside the chamber. Use high-precision tweezers to carefully pick up the diamond substrate 1 and place it at the central position of the heat-dissipating molybdenum carrier. To ensure the accuracy of the placement position, the pre-set crosshair inside the chamber can be used as a reference. By adjusting the position of the diamond substrate 1, make its center coincide with the intersection point of the crosshair. After placement, gently press the edge of the diamond substrate 1 to ensure full contact with the heat-dissipating molybdenum carrier to guarantee good heat dissipation effect.
[0026] In some embodiments, refer to Figures 1 to 3 , in step three, the microwave input power is 2000W, and the ratio of borane / hydrogen in the unit volume of the borane-hydrogen mixed gas is 1 / 10000. After placing the diamond substrate 1, slowly close the hatch of the MPCVD chamber and check the sealing condition of the hatch. Through the observation window on the chamber, confirm again whether the position of the diamond substrate 1 is correct. Next, perform subsequent operations such as vacuum pumping and introducing reaction gases according to the operating procedures of the MPCVD equipment.
[0027] Preferably, use an electronic balance to weigh the cleaned diamond substrate 1 and record its mass. At the same time, use a micrometer to measure its thickness to ensure that its various parameters meet the process requirements. If the mass or thickness exceeds the allowable error range, the diamond substrate 1 needs to be further processed or replaced.
[0028] Select an adjustable heat-dissipating molybdenum carrier. This molybdenum carrier has four adjustable support feet. By adjusting the height of the support feet, the levelness of the molybdenum carrier and the placement height of the diamond substrate 1 can be precisely adjusted. Before placing the heat-dissipating molybdenum carrier into the MPCVD chamber, use a level to perform a preliminary level adjustment on it to make the levelness error of the molybdenum carrier surface less than 0.1°.
[0029] Place the adjustable heat-dissipating molybdenum carrier on the sample stage of the MPCVD chamber. Use a manipulator to place the diamond substrate 1 at the central position of the heat-dissipating molybdenum carrier. Through the control system outside the chamber, adjust the four support feet of the heat-dissipating molybdenum carrier to make the surface of the diamond substrate 1 horizontal and its height match the microwave focusing position of the MPCVD equipment. The height and levelness of the diamond substrate 1 can be monitored in real time through the laser rangefinder installed inside the chamber, and precise adjustment can be made according to the monitoring results.
[0030] After adjustment, check the position and state of the diamond substrate 1 again to ensure it is in the best process position. Close the chamber hatch and start the vacuum pumping system of the MPCVD equipment to reduce the air pressure inside the chamber to below 1×10⁻³ Pa, and then introduce reaction gases according to the preset process parameters to start the chemical vapor deposition process.
[0031] In some embodiments, referring to Figures 1 to 3 , in step six, molybdenum is used as the evaporation material. After being made into a shape matching the surface shape of the diamond, it is placed in the crucible of the evaporation stage. The boron-doped diamond 2 sample is fixed on the substrate holder and placed in the vacuum coating chamber. The vacuum system is started to pump the vacuum to below 1E-6 mbar. The electron beam heating method is selected to evaporate molybdenum. The molybdenum vapor moves in the vacuum environment and condenses on the diamond surface, finally forming a molybdenum film. For example, if the evaporation source uses molybdenum particles with a purity of 99.995% and a particle size of 3-5 mm, a molybdenum evaporation boat (curvature radius deviation < 5 μm) matching the diamond surface is prepared by CNC precision machining, and pre-melting treatment is carried out. Under a vacuum of 5*10 -6 mbar, pre-evaporation coating is carried out at a rate of 0.5 Å / s for 30 seconds to remove the surface oxide.
[0032] In some embodiments, referring to Figures 1 to 3 , the thickness of the molybdenum film formed in step six is 1-5 nm. After the coating is completed, the heating source is turned off, and the vacuum coating chamber is allowed to cool naturally. After cooling to room temperature, the diamond sample is taken out.
[0033] In some embodiments, referring to Figures 1 to 3 , in step seven, the sulfidation time is 30-120 min, and the sulfidation time is reasonably selected or adjusted according to the thickness of the molybdenum film; after the growth is completed, the temperature in the single-zone furnace reaction chamber is slowly decreased to room temperature, and the temperature decrease rate is ≤5 °C / min. After the temperature decrease is completed, argon is introduced into the reaction chamber, and the reaction chamber is opened to obtain the n-MoS2 / P-diamond heterostructure.
[0034] In some embodiments, referring to Figures 1 to 3 , in step seven, the sulfidation time is 60 min, and the temperature decrease rate is 3 °C / min.
[0035] In some embodiments, referring to Figures 1 to 3 , in step eight, generally, the difference between the two characteristic peaks of bulk molybdenum disulfide is about 21.5 cm -1 . As the number of molybdenum disulfide layers decreases, the two characteristic peaks will show corresponding shifts, and the difference gradually becomes smaller. Among them, the difference between the characteristic peaks corresponding to monolayer MoS2 is 19 cm -1 . The test conditions are standardized. A 532 nm laser (power < 1 mW, avoiding thermal effects) is used, the objective lens NA = 0.75, the spot size is ~1 μm, and the standard silicon wafer 520.7 cm -1 peak (error ±0.2 cm -1 ) is calibrated.
[0036] In some embodiments, referring to Figures 1 to 3 , in step seven, a 2-3 layer molybdenum disulfide thin film 3 is prepared on the diamond substrate 1.
[0037] In some embodiments, referring to Figures 1 to 3 , in step seven, the sulfur vapor pressure is 30 Pa and the sulfidation temperature is 900 °C.
[0038] The method for preparing the molybdenum disulfide / diamond heterostructure of the present invention includes the following two aspects: In the first aspect, boron-doped single-crystal diamond is prepared by the MPCVD method. The sources used are methane, hydrogen, and borane. The growth thickness ranges from dozens of nanometers to hundreds of nanometers, obtaining a P-diamond structure. There are many related research results, which will not be elaborated here. The substrate usually uses diamond material as the deposition substrate to ensure that the prepared single-crystal diamond has good quality. At the same time, the diamond substrate has good heat dissipation characteristics.
[0039] In the second aspect, a molybdenum disulfide thin film 3 is prepared on the surface of boron-doped diamond 2 by the single-zone sulfidation deposition method. This method is based on the chemical reaction between molybdenum and sulfur. The P-diamond pre-deposited with a molybdenum coating and sulfur powder are placed in the same reaction zone. Under suitable process conditions, the sulfur powder sublimes to form sulfur vapor, and the molybdenum coating reacts with the sulfur vapor, thereby generating molybdenum disulfide on the diamond substrate 1.
[0040] Among them, in the second aspect, the P-diamond with a molybdenum layer is obtained by depositing a molybdenum film with a thickness of several nanometers to dozens of nanometers on the diamond surface by evaporation coating. The thickness of the molybdenum thin film should not be too thick to avoid incomplete sulfidation in the subsequent process. Specifically, in a high-vacuum environment, the molybdenum source is heated to evaporate into gaseous atoms and then deposited on the substrate surface.
[0041] Among them, in the second aspect, the single-zone sulfidation deposition method has the advantages of simple process steps and high product purity, meeting its application in the field of optoelectronic devices that require high material purity; at the same time, the single-zone sulfidation deposition method can effectively overcome the stress problem caused by lattice mismatch and improve compatibility.
[0042] Among them, in the second aspect, oxygen can be introduced during the reaction to dope and modify the MoS2 thin film, adjust the conductivity of the MoS2 thin film, and obtain the required heterojunction performance characteristics. At the same time, it is required to select a suitable sulfidation temperature, generally 800 - 950 °C, to avoid carbonization caused by the temperature exceeding 1000 °C; the sulfidation time is 30 - 120 minutes. Too long a time may lead to the formation of MoC; the sulfur vapor pressure is about 10 - 50 Pa to achieve stable control of the sublimation of sulfur powder; the cooling rate during the cooling process after growth is required to be ≤ 5 °C / min to prevent the film layer from cracking due to thermal stress. Due to the high thermal conductivity of the diamond substrate 1, the P-type diamond layer and the N-type MoS2 thin film have good semiconductor properties, and the obtained device performance is excellent.
[0043] The carbide-free single-zone sulfidation method for preparing molybdenum disulfide on a diamond substrate 1 has the following advantages: 1) Directly synthesize MoS2 on the diamond surface to avoid the defects of the transfer process; 2) Inhibit the Mo-C reaction at high temperatures to ensure the chemical purity of the interface; 3) Optimize the thermodynamic parameters to alleviate the thermal stress mismatch problem of the heterostructure.
[0044] The present invention effectively combines the performance advantages of molybdenum disulfide and diamond materials. The breakthrough of such technology will promote the practical application process of diamond-based heterojunction devices in the fields of 5G communication, deep space exploration, and nuclear energy equipment.
[0045] The present invention is applied to the field of photodetectors. The combination of the high light absorption rate of MoS2 and the fast carrier transport of diamond can improve the response speed and quantum efficiency, and is suitable for ultraviolet-visible light detection. The present invention is also applicable to field effect transistors. By utilizing the high breakdown field strength of diamond and the high electron mobility of MoS2, high-temperature and high-frequency devices can be developed, which are suitable for 5G communication and electric vehicle inverters. The present invention is also applicable to solar cells. If a type-II energy band alignment is formed in the heterojunction, efficient separation of photo-generated carriers can be achieved, and the energy conversion efficiency can be improved.
[0046] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for preparing a molybdenum disulfide / diamond heterostructure, characterized in that: The following steps are involved: Step 1: ultrasonically clean the diamond substrate using an organic solvent to remove impurities on the surface of the diamond substrate and improve the purity of the material growth; Step 2: Place the cleaned diamond substrate into the MPCVD chamber, select a suitable heat dissipation molybdenum tray, and place the diamond substrate in the center of the heat dissipation molybdenum tray; Step 3: Close the MPCVD chamber, use a mechanical pump and a molecular pump to evacuate the MPCVD chamber, and wait until the vacuum degree in the MPCVD chamber is below 1E-6 mbar. Then, start the process, introduce 188 sccm of hydrogen into the MPCVD chamber, wait until the gas pressure in the MPCVD chamber reaches 25 mbar, turn on the microwave source, and start the microwave ignition. After the MPCVD chamber is heated to 900°C, introduce 10 sccm of methane and 2 sccm of borane-hydrogen mixture, and grow at the controlled temperature for 15 minutes. Step 4: After the growth is completed, turn off the borane hydrogen mixture and methane, alternately reduce the pressure and power in the MPCVD chamber to cool down, turn off the hydrogen, evacuate the MPCVD chamber to below 1E-6 mbar, fill it with nitrogen, and take out the diamond substrate sample; Step 5, using a concentrated sulfuric acid / concentrated nitric acid mixed solution to clean the grown boron-doped diamond sample at high temperature to remove the non-diamond phase remaining in the growth process; Step 6, depositing a molybdenum film on the diamond surface by evaporation coating; Step 7, placing the diamond substrate and sulfur powder into the reaction chamber of the single-zone furnace, closing the reaction chamber, evacuating the reaction chamber to below 1E-6 mbar to exhaust air and impurities to prevent unnecessary oxidation reactions during the reaction process, gradually increasing the temperature of the single-zone furnace according to a gradient heating program, first to 800°C, keeping it warm for 10 minutes, and then heating it to 900°C to make the sulfur powder sublimate to form sulfur vapor, the sulfur vapor pressure is 10-50Pa, the sulfur vapor reacts with the molybdenum film deposited on the diamond substrate to undergo a sulfurization reaction, the sulfurization temperature is 800-950°C, and a molybdenum disulfide film grows on the diamond surface; obtaining an n-MoS2 / P-diamond heterostructure; Step 8: Use Raman spectrometer to characterize the MoS2 film. The Raman characteristic peak is located at E 1 2g 383cm -1 , A 1g 404.5cm -1 The difference between the two characteristic peaks is 21.5 cm -1 .
2. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step 1, the organic solvent is one of acetone and anhydrous ethanol.
3. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step 3, the microwave input power is 2000W, and the ratio of borane to hydrogen per unit volume in the borane-hydrogen mixture is 1 / 10000.
4. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step six, molybdenum is used as an evaporation material. It is made into a shape that matches the surface shape of the diamond and then placed in a crucible on the evaporation table. The boron-doped diamond sample is fixed on a substrate holder and placed in a vacuum coating chamber. The vacuum system is started and evacuated to below 1E-6mbar. Electron beam heating is used to evaporate the molybdenum. The molybdenum vapor moves in a vacuum environment and condenses on the surface of the diamond to form a molybdenum film.
5. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 4, characterized in that: The thickness of the molybdenum film formed in step six is 1-5 nm. After the coating is completed, the heating source is turned off, and the vacuum coating chamber is allowed to cool naturally. The diamond sample is taken out after cooling to room temperature.
6. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step seven, the sulfurization time is 30-120 minutes, and the sulfurization time is reasonably selected or adjusted according to the thickness of the molybdenum film; after the growth is completed, the temperature in the single-zone furnace reaction chamber is slowly reduced to room temperature, and the temperature drop rate is ≤5°C / min. After the cooling is completed, argon gas is introduced into the reaction chamber, and the reaction chamber is opened to obtain an n-MoS2 / P-diamond heterostructure.
7. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 6, characterized in that: In step seven, the vulcanization time is 60 min and the temperature drop rate is 3°C / min.
8. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step 8, the difference between the two characteristic peaks of bulk MoS2 is 21.5 cm -1 As the number of MoS2 layers decreases, the two characteristic peaks move and the difference gradually decreases. The characteristic peak difference corresponding to the single-layer MoS2 is 19 cm -1 .
9. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step seven, 2-3 layers of molybdenum disulfide thin films are prepared on a diamond substrate.
10. The method for preparing a molybdenum disulfide / diamond heterostructure according to claim 1, characterized in that: In step seven, the sulfur vapor pressure is 30 Pa and the sulfurization temperature is 900°C.