Preparation method of molybdenum sulfide-molybdenum selenide transverse heterostructure

Abstract

The invention relates to a preparation method of a molybdenum sulfide-molybdenum selenide transverse heterostructure, and belongs to the technical field of nano materials. Pre-cleaning a silicon single crystal substrate; the preparation method comprises the following steps: respectively placing sulfur powder and selenium powder in a medium-temperature area in a pipe front and back, then placing a molybdenum source in a high-temperature area in the same pipe, placing a pre-cleaned silicon single crystal substrate in a position 2-3cm away from a port of the high-temperature area in the pipe, simultaneously and respectively heating the medium-temperature area and the high-temperature area in a sectional manner under an argon condition, and cooling to room temperature, thereby obtaining the silicon single crystal substrate. The molybdenum sulfide-molybdenum selenide transverse heterostructure (MoS2 / MoSe2 heterostructure) is grown on a silicon single crystal substrate. The molybdenum sulfide-molybdenum selenide transverse heterostructure grows on the silicon substrate, the obtained heterointerface potential barrier is low, the preparation method is easy to operate and good in controllability and safety, and meanwhile the problems that a mechanical stripping method is complex in process and materials are prone to being polluted in the stripping process are solved.

Description

Technical Field

[0001] The invention relates to a method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure, belonging to the technical field of nanomaterials. Background Art

[0002] Since the discovery of graphene, two-dimensional materials have aroused a research boom due to their ultra-thin planar structure and large band gap range. After the development in recent years, the family of two-dimensional materials has been growing continuously. The two-dimensional heterojunction of two-dimensional transition metal chalcogenides has complementary advantages due to its atomic-scale thickness and unique physical properties, and has great application potential in the next generation of electronics and optoelectronics. In addition to the classic TMDCs materials, a variety of two-dimensional elemental materials and two-dimensional oxide materials have been discovered. Two-dimensional heterojunction materials not only further expand the family of two-dimensional materials, but also can develop new materials that are beneficial to social progress and scientific and technological development through the characteristics and advantages of heterojunctions.

[0003] The commonly used method for preparing MoS / MoSe heterojunctions is mechanical exfoliation. Using mechanical exfoliation, different two-dimensional materials can be stacked together to prepare heterojunctions, and multiple two-dimensional layered materials can be stacked layer by layer to form heterojunctions. However, this method cannot accurately control its crystal orientation, and the direct interface between layers is easily contaminated. At the same time, this artificial integration method is not suitable for large-scale production, which hinders the further development and research of heterojunctions.

[0004] Since the 21st century, two-dimensional materials have attracted widespread attention due to their excellent physical and chemical properties and unique low-dimensional optoelectronic properties. Two-dimensional transition metal sulfides have excellent optical, electrical, and mechanical properties and have great potential in optoelectronic devices, materials science, energy, biomedicine, etc. For example, MoS2, one of the representatives of two-dimensional transition metal sulfides (TMDs), has a high intrinsic carrier mobility and exhibits different electronic bulk properties when the number of layers changes, and has the potential to be used in high-performance optoelectronic devices. Summary of the invention

[0005] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure. The present invention grows a molybdenum sulfide-molybdenum selenide lateral heterostructure on a silicon substrate. The heterogeneous interface barrier obtained by the present invention is low, the preparation method is simple to operate, and has good controllability and safety. At the same time, the problem of complex process of mechanical stripping and easy contamination of materials during the stripping process is overcome. The present invention is implemented by the following technical solutions.

[0006] A method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure, the specific steps of which include:

[0007] Step 1, pre-cleaning the silicon single crystal substrate;

[0008] Step 2: Place sulfur powder and selenium powder in the medium temperature zone of the tube respectively, then place a molybdenum source in the high temperature zone of the same tube, and place the pre-cleaned silicon single crystal substrate 2-3 cm from the high temperature zone port of the tube. Under argon conditions, heat the medium temperature zone and the high temperature zone in sections at the same time. After cooling to room temperature, a molybdenum sulfide-molybdenum selenide lateral heterostructure (MoS2 / MoSe2 heterostructure) is grown on the silicon single crystal substrate.

[0009] In the step 1, the silicon single crystal substrate is ultrasonically cleaned in acetone, anhydrous ethanol and deionized water in sequence.

[0010] In step 2, the mass ratio of sulfur powder to selenium powder is 1:(0.9-1), and the interval is 10-12 cm; the interval between selenium powder and silicon single crystal substrate is 15 cm.

[0011] In step 2, the molybdenum source is molybdenum oxide.

[0012] The argon gas condition control method in step 2 is: reduce the vacuum pressure in the tube by 5 Pa, introduce high-purity argon gas at a flow rate of 100 sccm until it reaches normal pressure, and repeat 2-3 times; adjust the flow rate of high-purity argon gas to 50 sccm as a carrier gas until it cools to room temperature.

[0013] In the step 2, the medium temperature zone is rapidly heated to 300-350°C at a heating rate of 4°C / min, then kept warm for 30 minutes, then cooled to 200°C at a rate of 2°C / min, and finally cooled naturally to room temperature.

[0014] In step 2, the high temperature zone is heated to 700-900°C at 10°C / min, then kept at this temperature for 30 minutes, then the temperature is lowered to 200°C at 10°C / min, and finally cooled naturally to room temperature.

[0015] Compared with the mechanical stripping method, the advantages of the present invention are:

[0016] 1. The molybdenum sulfide-molybdenum selenide lateral heterostructure of the present invention improves the problem that the stacking orientation in the heterojunction is difficult to control and is easily contaminated. The prepared MoS2 / MoSe2 heterojunction has a larger size, higher quality, uniform thickness and good morphology.

[0017] 2. The method of the present invention is easy to control and can be conveniently used for large-scale production, providing a simpler preparation method for the preparation of MoS2 / MoSe2 lateral heterojunction.

[0018] The method for preparing a two-dimensional MoS2 / MoSe2 lateral heterojunction on a silicon substrate of the present invention can be applied to optical communications, transistors, photodetectors and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an optical microscope image of the MoS2 / MoSe2 lateral heterostructure prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0021] Test instruments and equipment: airflow meter, Beike three-zone tube furnace, quartz tube

[0022] raw material:

[0023] Silicon single crystal: purchased from MaTecK, purity 99.999%.

[0024] Selenium powder: purchased from Sigma-Aldrich, purity 99.9%.

[0025] Sulfur powder: purchased from Sigma-Aldrich, purity 99.9%.

[0026] Molybdenum oxide powder: purchased from Qingdao Shengming Molybdenum Industry Co., Ltd., purity 99.9%.

[0027] Example 1

[0028] The method for preparing the molybdenum sulfide-molybdenum selenide lateral heterostructure comprises the following specific steps:

[0029] Step 1, pre-cleaning the silicon single crystal substrate; the silicon single crystal substrate is placed in acetone, anhydrous ethanol and deionized water for ultrasonic cleaning (power is 80Hz) for 3 minutes, and then blown dry for standby use; acetone and anhydrous ethanol are used to wipe the quartz tube to remove organic and inorganic impurities, and the cleaned quartz tube is placed on a three-temperature zone tube furnace for assembly and standby use;

[0030] Step 2, put 0.2g sulfur powder into ceramic boat 1, put 0.2g selenium powder into ceramic boat 2, and place ceramic boat 1 and ceramic boat 2 in the medium temperature zone of the quartz tube (ceramic boat 1 and ceramic boat 2 are separated by 10cm), then place ceramic boat 3 containing 0.18g molybdenum source in the high temperature zone of the quartz tube, place the pre-cleaned silicon single crystal substrate 2cm from the high temperature zone port in the tube, and control the interval between ceramic boat 2 and the silicon single crystal substrate to be 15cm, under argon conditions (reduce the vacuum pressure in the tube by 5pa, introduce high-purity argon gas at a flow rate of 100sccm until it reaches normal pressure, repeat 2-3 times; adjust the flow rate of high-purity argon gas to To 50sccm as the carrier gas until it is cooled to room temperature), and at the same time, the medium temperature zone and the high temperature zone are heated in stages, the medium temperature zone is rapidly heated to 300°C at a heating rate of 4°C / min, and then kept warm for 30min, then cooled to 200°C at 2°C / min, and finally cooled to room temperature naturally; the high temperature zone is heated to 800°C at 10°C / min, and then kept warm for 30min, then the temperature is lowered, and it is cooled to 200°C at 10°C / min, and finally cooled to room temperature naturally; after cooling to room temperature, a molybdenum sulfide-molybdenum selenide lateral heterostructure (MoS2 / MoSe2 heterostructure) is grown on a silicon single crystal substrate.

[0031] The optical microscope image of the molybdenum sulfide-molybdenum selenide lateral heterostructure (MoS2 / MoSe2 heterostructure) grown on a silicon single crystal substrate of the present invention is as follows: Figure 1 As shown, from Figure 1 It can be seen that the morphology of the MoS2 / MoSe2 heterostructure is triangular.

[0032] Example 2

[0033] The method for preparing the molybdenum sulfide-molybdenum selenide lateral heterostructure comprises the following specific steps:

[0034] Step 1, pre-cleaning the silicon single crystal substrate; the silicon single crystal substrate is placed in acetone, anhydrous ethanol and deionized water for ultrasonic cleaning (power is 80Hz) for 3 minutes, and then blown dry for standby use; acetone and anhydrous ethanol are used to wipe the quartz tube to remove organic and inorganic impurities, and the cleaned quartz tube is placed on a three-temperature zone tube furnace for assembly and standby use;

[0035] Step 2, 0.2g of sulfur powder is put into ceramic boat 1, 0.18g of selenium powder is put into ceramic boat 2, and ceramic boat 1 and ceramic boat 2 are placed in the medium temperature zone of the quartz tube (ceramic boat 1 and ceramic boat 2 are separated by 12cm), and then ceramic boat 3 containing 0.18g of molybdenum source is placed in the high temperature zone of the quartz tube, and the pre-cleaned silicon single crystal substrate is placed 3cm from the high temperature zone port in the tube, and the ceramic boat 2 is controlled to be 15cm away from the silicon single crystal substrate, under argon conditions (the vacuum pressure in the tube is reduced by 5pa, and high-purity argon gas is introduced at a flow rate of 100sccm until it reaches normal pressure, and repeated 2-3 times; the high-purity argon gas flow rate is adjusted To 50sccm as the carrier gas until it is cooled to room temperature), and at the same time, the medium temperature zone and the high temperature zone are heated in stages, the medium temperature zone is rapidly heated to 350°C at a heating rate of 4°C / min, and then kept warm for 30 minutes, then cooled to 200°C at 2°C / min, and finally cooled to room temperature naturally; the high temperature zone is heated to 700°C at 10°C / min, and then kept warm for 30 minutes, and then the temperature is reduced, cooled to 200°C at 10°C / min, and finally cooled to room temperature naturally; after cooling to room temperature, a molybdenum sulfide-molybdenum selenide lateral heterostructure (MoS2 / MoSe2 heterostructure) is grown on a silicon single crystal substrate.

[0036] Example 3

[0037] The method for preparing the molybdenum sulfide-molybdenum selenide lateral heterostructure comprises the following specific steps:

[0038] Step 1, pre-cleaning the silicon single crystal substrate; the silicon single crystal substrate is placed in acetone, anhydrous ethanol and deionized water for ultrasonic cleaning (power is 80Hz) for 3 minutes, and then blown dry for standby use; acetone and anhydrous ethanol are used to wipe the quartz tube to remove organic and inorganic impurities, and the cleaned quartz tube is placed on a three-temperature zone tube furnace for assembly and standby use;

[0039] Step 2, put 0.2g sulfur powder into ceramic boat 1, put 0.18g selenium powder into ceramic boat 2, and place ceramic boat 1 and ceramic boat 2 in the medium temperature zone of the quartz tube (ceramic boat 1 and ceramic boat 2 are separated by 11cm), then place ceramic boat 3 containing 0.18g molybdenum source in the high temperature zone of the quartz tube, place the pre-cleaned silicon single crystal substrate 3cm from the high temperature zone port in the tube, and control the interval between ceramic boat 2 and the silicon single crystal substrate to be 15cm, under argon conditions (reduce the vacuum pressure in the tube by 5pa, introduce high-purity argon gas at a flow rate of 100sccm until it reaches normal pressure, repeat 2-3 times; adjust the flow rate of high-purity argon gas to To 50sccm as the carrier gas until it is cooled to room temperature), and at the same time, the medium temperature zone and the high temperature zone are heated in stages, the medium temperature zone is rapidly heated to 320°C at a heating rate of 4°C / min, and then kept warm for 30min, then cooled to 200°C at 2°C / min, and finally cooled to room temperature naturally; the high temperature zone is heated to 900°C at 10°C / min, and then kept warm for 30min, then the temperature is reduced, and it is cooled to 200°C at 10°C / min, and finally cooled to room temperature naturally; after cooling to room temperature, a molybdenum sulfide-molybdenum selenide lateral heterostructure (MoS2 / MoSe2 heterostructure) is grown on a silicon single crystal substrate.

[0040] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure, characterized in that The specific steps include: Step 1, pre-cleaning the silicon single crystal substrate; Step 2: Place sulfur powder and selenium powder in the medium temperature zone of the tube respectively, then place a molybdenum source in the high temperature zone of the same tube, place the pre-cleaned silicon single crystal substrate 2-3 cm from the high temperature zone port of the tube, and heat the medium temperature zone and the high temperature zone in sections at the same time under argon conditions. After cooling to room temperature, a molybdenum sulfide-molybdenum selenide lateral heterostructure is grown on the silicon single crystal substrate.

2. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: In the step 1, the silicon single crystal substrate is ultrasonically cleaned in acetone, anhydrous ethanol and deionized water in sequence.

3. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: In step 2, the mass ratio of sulfur powder to selenium powder is 1:(0.9-1), and the interval is 10-12 cm; the interval between selenium powder and silicon single crystal substrate is 15 cm.

4. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: In step 2, the molybdenum source is molybdenum oxide.

5. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: The argon gas condition control method in step 2 is: reduce the vacuum pressure in the tube by 5 Pa, introduce high-purity argon gas at a flow rate of 100 sccm until it reaches normal pressure, and repeat 2-3 times; adjust the flow rate of high-purity argon gas to 50 sccm as a carrier gas until it cools to room temperature.

6. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: In the step 2, the medium temperature zone is rapidly heated to 300-350°C at a heating rate of 4°C / min, then kept warm for 30 minutes, then cooled to 200°C at a rate of 2°C / min, and finally cooled naturally to room temperature.

7. The method for preparing a molybdenum sulfide-molybdenum selenide lateral heterostructure according to claim 1, characterized in that: In step 2, the high temperature zone is heated to 700-900°C at 10°C / min, then kept at this temperature for 30 minutes, then the temperature is lowered to 200°C at 10°C / min, and finally cooled naturally to room temperature.

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