A uniaxial strain force application device for large-scale substrate two-dimensional layered materials

Abstract

The present invention discloses a uniaxial strain force device for large-scale substrate two-dimensional layered materials, the device comprises an adapter plate, a support device, two displacement members and two limit members; wherein a through hole is provided in the middle of the adapter plate; the support device is fixedly mounted on the bottom surface of the adapter plate, and a receiving space for a transmission device is formed below the through hole; the two displacement members are relatively arranged on the top of the adapter plate; each limit member is provided with a limit structure for limiting one end of the substrate; and a limit space of the substrate is formed between the two limit members. The device can realize the transmission research of two-dimensional layered materials with large-scale substrates.

Description

Technical Field

[0001] The present invention relates to the technical field of two-dimensional layered nanomaterials, and in particular to a uniaxial strain force application device for large-scale substrate two-dimensional layered materials. Background Art

[0002] Two-dimensional layered nanomaterials, such as graphene and two-dimensional transition metal sulfides, are commonly found in materials whose interlayers are connected by van der Waals forces. This type of material has attracted widespread attention due to its unique properties in optics, electricity, heat, mechanics, etc. Tungsten diselenide (WSe2) is an important representative of two-dimensional transition metal sulfides. Bulk WSe2 is usually a black or gray layered solid and is a good lubricant additive. When the WSe2 material changes from bulk to a single layer, its band structure will change from an indirect band gap to a direct band gap. Two-dimensional layered nanomaterials have very broad application prospects and can be used in many fields. Applying uniaxial strain to two-dimensional layered materials can usually change their physical properties. Therefore, studying the changes in the properties of such materials under uniaxial strain is of great significance for the understanding of their physicochemical properties and the extension of their application fields.

[0003] The study of applying uniaxial strain to two-dimensional layered materials requires the use of a uniaxial strain force device, which refers to a device that applies strain in a specific direction to two-dimensional layered nanomaterial samples such as graphene and transition metal sulfides prepared by mechanical exfoliation, chemical vapor deposition, etc. Generally speaking, the substrate is deformed by mechanical bending so that the uniaxial strain is transferred to the sample through the substrate. Under the action of uniaxial strain, the physical properties of two-dimensional layered materials will change, usually manifested as changes in the lattice constant leading to changes in the corresponding vibration mode and band structure. Then, through characterization methods such as photoluminescence spectroscopy and Raman spectroscopy, the changes in the physical properties of the sample with uniaxial strain can be intuitively and accurately reflected.

[0004] However, the current substrate materials used to transmit strain are usually tens of millimeters in size, and traditional sample stages are unable to place such large-scale substrates and apply strain; moreover, traditional three-axis or four-axis devices for applying strain can only perform reflective measurements on samples, and the substrates are usually transparent substrates such as PC, PET, PETG, etc., which causes the reflected light intensity to become weak, which is not conducive to subsequent spectral analysis of the samples. Summary of the invention

[0005] In view of this, the present invention provides a uniaxial strain force applying device for two-dimensional layered materials on large-scale substrates. The uniaxial strain force applying device can not only apply force in a specific direction to the two-dimensional layered materials on the large-scale substrate, but also facilitate transmission measurement of the substrate, thereby improving the convenience of uniaxial strain research on two-dimensional layered materials on large-scale substrates.

[0006] The present invention adopts the following specific technical solutions:

[0007] A uniaxial strain force applying device for large-scale substrate two-dimensional layered materials, comprising a transfer plate, a support device, two displacement members and two limit members;

[0008] A through hole is provided in the middle of the adapter plate;

[0009] The supporting device is fixedly mounted on the bottom surface of the adapter plate, and forms a transmission device accommodating space below the through hole;

[0010] The two displacement members are arranged oppositely on the top surface of the adapter plate and located on both sides of the through hole;

[0011] Each displacement member includes a moving part, a fixed part and a driving part, wherein the fixed part is fixedly mounted on the adapter plate, and the moving part can be slidably mounted on the top of the fixed part along the arrangement direction of the two displacement members;

[0012] Each of the moving parts is fixedly mounted with a limiting member; the two limiting members are arranged opposite to each other; each of the limiting members is provided with a limiting structure for limiting one end of the substrate;

[0013] A limiting space of the substrate is formed between the two limiting members;

[0014] The driving part is fixedly mounted on the fixed part and connected to the moving part, and is used for driving the moving part to slide relative to the fixed part.

[0015] Further, the limiting member is a flat plate;

[0016] The plate is horizontally fixedly mounted on the top surface of the moving part.

[0017] Furthermore, the limiting structure is a long groove.

[0018] Furthermore, the cross-section of the long groove is in a “∠” shape.

[0019] Furthermore, the long grooves are arranged at the same horizontal height of the opposite sides of the plate, so that the “∠”-shaped grooves are opposite to each other.

[0020] Further, the moving part is a slider;

[0021] The fixing part is a guide rail.

[0022] Further, the fixing portion is a bottom plate;

[0023] The moving part is a top plate;

[0024] The driving part is a micrometer screw with a scale;

[0025] The micrometer screw is fixedly mounted on a side surface of the top plate. Rotating the micrometer screw can drive the top plate to slide relative to the bottom plate, and the sliding distance is recorded by a scale.

[0026] Furthermore, the device also includes a camera device;

[0027] The camera device is fixedly mounted on the adapter plate and is used to capture images during the experiment and transmit the images to a computer connected to the computer signal.

[0028] Further, the apparatus includes a spectroscopy device;

[0029] The spectral equipment is used to perform photoluminescence spectroscopy and Raman spectroscopy analysis on the two-dimensional layered material on the substrate to study the properties of the two-dimensional layered material under uniaxial strain.

[0030] Further, the through hole is a circular hole;

[0031] The supporting device is a supporting rod which is arranged in a vertical direction and fixedly connected to the four corners of the adapter plate.

[0032] Beneficial effects:

[0033] (1) The uniaxial strain force-applying device of the present invention is provided with two relatively movable displacement members on the adapter plate, and the two displacement members are provided with position-limiting members capable of limiting the substrate on which the two-dimensional layered material is located, so that a large-scale substrate can be placed between the movable displacement members, and a force in a specific direction can be applied to the substrate by the movement of the displacement members; moreover, the position where the displacement member is fixedly installed on the adapter can be flexibly set according to the size of the substrate, so that the force-applying device can be applicable to a larger range of substrate sizes; in addition, the uniaxial strain force-applying device of the present invention is provided with a through hole in the middle of the adapter plate, and a support device is fixedly installed on the bottom surface of the adapter plate, so that a transmission device accommodating space can be formed below the through hole, so that after the adapter plate is connected to an optical platform, a height-adjustable support or a two-dimensional translation stage through the support device, a transmission device composed of relevant elements such as an objective lens, a lens and an aperture can be introduced below the through hole, so as to realize transmission measurement of the sample. The device has a small number of components, a compact structure, and simple operation, making it convenient to study two-dimensional layered materials with large-scale substrates under uniaxial strain.

[0034] (2) The uniaxial strain force-applying device of the present invention sets the structure for limiting the substrate on the side of the limiting member, which can stably limit the substrate between the two displacement members, so that when force is applied to the substrate, the substrate is not easy to pop out, thereby improving the safety and reliability of the device.

[0035] (3) The uniaxial strain force-applying device of the present invention sets the limiting structure as a long groove, so that when placing the substrate, it is only necessary to insert the substrate from one end of the long groove, which is very convenient to operate; moreover, after the long groove is set to a relative "∠" shape, when the substrate is bent, the two ends of the substrate can still rotate, so that the shape of the substrate after bending is closer to an arc, thereby improving the accuracy of subsequent uniaxial strain calculation of the substrate.

[0036] (4) The movable part of the displacement member in the uniaxial strain force application device of the present invention may be a guide rail, and the corresponding fixed part may be a slider. The sources of the guide rail and the slider are wide, and the movement of the slider relative to the guide rail can be easily controlled; moreover, the displacement member may also be a displacement table with a bottom plate, a top plate and a micrometer screw. The distance moved by the top plate can be accurately measured by the micrometer screw, thereby further improving the accuracy of subsequent uniaxial strain calculation of the substrate.

[0037] (5) The uniaxial strain force application device of the present invention is provided with a camera device and a spectral device. After the substrate is bent, photos can be taken by the camera device and the photos can be transmitted to a computer for subsequent processing. In addition, the two-dimensional layered nanomaterials can be quickly studied by photoluminescence spectroscopy and Raman spectroscopy under uniaxial strain, thereby improving the integration and informationization of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of a uniaxial strain force applying device for large-scale substrate two-dimensional layered materials of the present invention;

[0039] Figure 2 For a double-layer WSe2 material in use Figure 1 Schematic diagram of the changes in the photoluminescence spectrum under different uniaxial strains measured after the device is installed;

[0040] Figure 3 For use Figure 1 Schematic diagram of calculating the strain of two-dimensional layered materials after the device.

[0041] Among them, 1-adapter plate, 2-displacement member, 3-bottom plate, 4-top plate, 5-micrometer screw, 6-limiting member, 7-"∠"-shaped groove, 8-substrate, 9-through hole, 10-support rod DETAILED DESCRIPTION

[0042] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0043] This embodiment provides a uniaxial strain force applying device for large-scale substrate two-dimensional layered materials, such as Figure 1 As shown, the device includes an adapter plate 1, a supporting device, two displacement members 2 and two limit members 6.

[0044] Specifically, Figure 1 As shown, a through hole 9 is provided in the middle of the adapter plate 1; the supporting device is fixedly installed on the bottom surface of the adapter plate 1, and a accommodating space for the transmission device is formed below the adapter plate 1; two displacement members 2 are relatively arranged on the top surface of the adapter plate 1, and are located on both sides of the through hole 9; each displacement member 2 includes a moving part, a fixed part and a driving part; wherein the fixed part is fixedly installed on the adapter plate 1, and the moving part can be slidably installed on the top of the fixed part along the arrangement direction of the two displacement members 2; each moving part is fixedly installed with a limiting member 6; the two limiting members 6 are relatively arranged; each limiting member 6 is provided with a limiting structure for limiting one end of the substrate 8; a limiting space for the substrate 8 is formed between the two limiting members 6; the driving part is fixedly installed on the fixed part, and is connected to the moving part, and is used to drive the moving part to slide relative to the fixed part.

[0045] In this embodiment, the force-applying device is formed by arranging two relatively movable displacement members 2 on an adapter plate 1 made of hard aluminum material, and the two displacement members 2 are equipped with limiting members 6 that can limit the two-dimensional layered material, so that a large-scale substrate 8 can be placed between the movable displacement members 2, and the distance between the displacement members 2 can be adjusted by the installation position of the displacement members 2 on the adapter plate 1 (the displacement members 2 can be installed and fixed through the installation holes at different positions on the adapter plate 1), and a force in a specific direction can be applied to the substrate 8 through the movement of the displacement members 2, so it is applicable to substrates 8 of many sizes, especially large sizes. In addition, the uniaxial strain force-applying device is provided with a through hole 9 in the middle of the adapter plate 1, and a support device is fixedly installed on the bottom surface of the adapter plate 1. After the support device is fixedly installed on the bottom surface of the adapter plate 1, a receiving space for the transmission device is formed below the through hole 9. In this way, after the adapter plate 1 is connected to an optical platform, a height-adjustable support, or a two-dimensional translation stage through the support device, a transmission device composed of relevant components such as an objective lens, a lens, and an aperture can be introduced below the through hole, thereby realizing transmission measurement of the sample. Using transmission measurement can obtain a more direct and stronger sample signal than reflection measurement. Obviously, the device has a small number of components, a compact structure, and simple operation, which makes it convenient to study two-dimensional layered materials with large-scale substrates 8 under uniaxial strain.

[0046] The moving part can be a slider, the fixed part can be a guide rail, and the driving part can be a hand wheel. In this case, a hand wheel bracket can be fixedly installed at one end of the guide rail for installing the hand wheel. The hand wheel is connected to the slider through a screw rod, and the slider can be driven to move by turning the hand wheel. If this structural form is selected, the device has the advantages of a wide range of sources of guide rails and sliders, and can easily control the movement of the slider relative to the guide rail; in this embodiment, if Figure 1As shown, the above-mentioned moving part can also be the top plate 4. Correspondingly, the fixed part is the bottom plate 3, and the driving part is the micrometer screw 5. Rotating the micrometer screw 5 can drive the top plate 4 to slide relative to the bottom plate 3, and the sliding distance is recorded through the scale. At this time, the displacement member 2 forms the form of a displacement stage. The distance of the movement of the top plate 4 can be accurately measured through the micrometer screw 5, improving the accuracy of the subsequent uniaxial strain calculation of the substrate 8. It should be noted that in order to make the device quantify the bending degree of the substrate 8 (which can be measured by the movement distance of the displacement member) to more accurately study the properties of two-dimensional layered materials under uniaxial strain, in addition to the form of setting the micrometer screw 5 with a scale in this embodiment, a scale can also be set on the adapter plate 1 to quantify the movement distance of the displacement member 2. Obviously, the structural form of the displacement member 2 is diverse, and the corresponding structure for quantifying the movement distance of the displacement member 2 is also diverse, not limited to the above two forms.

[0047] As Figure 1 shown, in this embodiment, the limiting member 6 is a flat plate made of duralumin and is horizontally fixedly installed on the top surface of the moving part. Of course, since the limiting member 6 mainly moves with the moving part to exert a force on the substrate 8, it can also be in a block shape or other irregular shapes, or even a component composed of other parts; the limiting structure is a long groove, such as a long groove with an arc-shaped cross-section, a long groove with a "凵"-shaped cross-section, a long groove with an "∠"-shaped cross-section, etc. In this embodiment, a long groove with an "∠"-shaped cross-section is selected as the limiting structure and is set at the same horizontal height on the opposite side surfaces of the plate member, making the "∠"-shaped grooves 7 opposite to each other.

[0048] Since the structure for limiting the substrate 8 is arranged on the side surface of the limiting member 6, the substrate 8 can be stably restricted between the two displacement members 2, making it not easy for the substrate 8 to pop out when a force is applied to the substrate 8, improving the safety and reliability of the device; in addition, the long groove structure form makes it only necessary to insert the substrate 8 from one end of the long groove when placing the substrate 8, and the operation is very convenient; moreover, after the long groove is set to be opposite "∠"-shaped in this embodiment, when the substrate 8 bends, both ends of the substrate 8 can still rotate, making the shape of the substrate 8 closer to a circular arc after bending, improving the accuracy of the subsequent uniaxial strain calculation of the substrate 8.

[0049] In this embodiment, a camera device (not shown in the figure) can also be fixedly installed on the adapter plate 1 for taking images during the experiment and transmitting them to a computer signal-connected to it; further, a spectroscopic device (not shown in the figure) can also be fixedly installed on the adapter plate 1. The spectroscopic device is used to perform photoluminescence spectroscopy and Raman spectroscopy analysis on the two-dimensional layered material on the substrate 8 to study the properties of the two-dimensional layered material under uniaxial strain.

[0050] The force-applying device is provided with a camera and a spectral device, so that after the substrate 8 is bent, the camera can be used to take photos, and the photos can be transmitted to a computer for subsequent processing; and the two-dimensional layered nanomaterials can be quickly studied by photoluminescence spectroscopy and Raman spectroscopy under uniaxial strain, thereby improving the integration and informationization of the device. Figure 2 As shown, a double-layer WSe2 material is used Figure 1 Schematic diagram of the photoluminescence spectrum changes under different uniaxial strains measured by the force-applying device with the help of a camera and a spectral device.

[0051] like Figure 1 As shown, in this embodiment, the through hole 9 is set as a circular hole, and the diameter of the circular hole is 50mm. This size is applicable to most lenses of brands such as Daheng Optoelectronics, Nikon, and Sanfeng. Taking the objective lens of Nikon as an example, the diameter of its objective lens ranges from 29mm to 40mm, and the diameter of the objective lens in this range is smaller than the diameter of the circular hole. Of course, the shape and size of the through hole 9 can be flexibly designed according to actual needs. In addition, Figure 1 As shown, in this embodiment, the supporting device is selected as a supporting rod 10, one end of which is vertically fixedly installed at the four corners of the bottom surface of the adapter plate 1, and a thread can be set at the bottom of the supporting rod 10 to achieve a quick and detachable connection with an optical platform, a height-adjustable support, a two-dimensional translation stage, etc., and the supporting rod 10 can be designed as a height-adjustable structure so that the transmission device including the objective lens has sufficient and flexibly adjustable working space.

[0052] Furthermore, a method for calculating the strain of a two-dimensional layered material using the force applying device includes:

[0053] The substrate of the two-dimensional layered material is clamped between the two stoppers 6 through the “∠”-shaped groove 7;

[0054] Record the first readings of the two micrometer screws 5 respectively;

[0055] Rotate the micrometer screw 5 to drive the top plate 4 to move toward each other so that the substrate 8 bends;

[0056] The bent substrate 8 is photographed, and the second readings of the two micrometer screws 5 are recorded respectively;

[0057] Calculate the curvature radius of the substrate 8 based on the photo and the first and second readings of the micrometer screw 5;

[0058] The strain of the two-dimensional layered material is calculated based on the thickness and the radius of curvature of the substrate 8 .

[0059] In the above method, when the substrate 8 of the two-dimensional layered material is clamped between the two limit members 6 through the "∠"-shaped groove 7, the two surfaces of the two "∠"-shaped grooves 7 are kept in contact with the substrate 8 and there is no compression on the substrate 8. In this way, the movement of the top plate 4 can be completely used to apply force to the substrate 8, making the subsequent strain calculation results more accurate.

[0060] Specifically, the method for calculating the curvature radius of the substrate 8 is:

[0061] like Figure 3 (Omitted Figure 1 As shown in the supporting device in FIG. 1 , a substrate tangent is made through the contact point between the substrate 8 and the “∠”-shaped groove 7 in the photo, and the angle θ between the tangent and the horizontal plane is measured (27° in this embodiment);

[0062] Calculate the difference between the second reading and the first reading of the two micrometer screws 5 respectively;

[0063] The chord length a of the bent substrate 8 is calculated by formula (1):

[0064] a=mn (1)

[0065] Wherein, m is the initial length of the substrate 8; n is the sum of the difference between the second reading and the first reading of the two micrometer screws 5;

[0066] The curvature radius R of the substrate 8 is calculated according to formula (2):

[0067] R=a / 2sinθ (2)

[0068] The strain ε of the two-dimensional layered material is calculated according to formula (3):

[0069] ε=t / 2R (3)

[0070] Where t is the thickness of the substrate.

[0071] The above method is simple to operate and has high calculation accuracy.

[0072] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A uniaxial strain force applying device for large-scale substrate two-dimensional layered materials, characterized in that: It includes an adapter plate, a supporting device, two displacement members and two limit members; A through hole is provided in the middle of the adapter plate; The supporting device is fixedly mounted on the bottom surface of the adapter plate and forms a receiving space for the transmission device below the through hole; The two displacement members are arranged oppositely on the top surface of the adapter plate and located on both sides of the through hole; Each displacement member includes a moving part, a fixed part and a driving part, wherein the fixed part is fixedly mounted on the adapter plate, and the moving part can be slidably mounted on the top of the fixed part along the arrangement direction of the two displacement members; Each of the moving parts is fixedly mounted with a limiting member; the two limiting members are arranged opposite to each other; each of the limiting members is provided with a limiting structure for limiting one end of the substrate; A limiting space of the substrate is formed between the two limiting members; The driving part is fixedly mounted on the fixed part and connected to the moving part, and is used for driving the moving part to slide relative to the fixed part.

2. The force applying device according to claim 1, characterized in that: The limiting member is a flat plate; The flat plate is horizontally fixedly mounted on the top surface of the moving part.

3. The force applying device according to claim 2, characterized in that: The limiting structure is a long groove.

4. The force applying device according to claim 3, characterized in that: The cross section of the long groove is "∠"-shaped.

5. The force applying device according to claim 4, characterized in that: The long grooves are arranged at the same level of the opposite sides of the flat plate so that the "∠"-shaped grooves are opposite to each other.

6. The force applying device according to claim 5, characterized in that: The moving part is a slider; The fixing part is a guide rail.

7. The force applying device according to claim 5, characterized in that: The fixing portion is a bottom plate; The moving part is a top plate; The driving part is a micrometer screw with a scale; The micrometer screw is fixedly mounted on a side surface of the top plate. Rotating the micrometer screw can drive the top plate to slide relative to the bottom plate, and the sliding distance is recorded by a scale.

8. The force applying device according to any one of claims 1 to 7, characterized in that: It also includes video equipment; The camera device is fixedly mounted on the adapter plate and is used to capture images during the experiment and transmit the images to a computer connected to the computer signal.

9. The force applying device according to any one of claims 1 to 7, characterized in that: Also included are spectroscopy equipment; The spectral equipment is used to perform photoluminescence spectroscopy and Raman spectroscopy analysis on the two-dimensional layered material on the substrate to study the properties of the two-dimensional layered material under uniaxial strain.

10. The force applying device according to any one of claims 1 to 7, characterized in that: The through hole is a circular hole; The supporting device is a supporting rod which is arranged in a vertical direction and fixedly connected to the four corners of the adapter plate.

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