A two-dimensional material in-situ real-time measurement device and its application method

Abstract

The present invention discloses an in-situ real-time measurement device for two-dimensional materials and an application method thereof. The device includes a sample delivery unit, a light trap capture unit, a signal detection unit, a sample chamber, a signal solution unit, and a sample chamber environmental condition control unit. Application method: load the two-dimensional material to be measured into the sample delivery unit; turn on the laser of the light trap capture unit to form a light trap in the sample chamber; transfer the two-dimensional material of the sample delivery unit into the light trap of the light trap capture unit; use the sample chamber environmental condition control unit to control the environmental conditions of the sample chamber; collect the Raman spectrum signal of the two-dimensional material into the signal detection unit and save it; after the signal solution unit recognizes the Raman spectrum signal of the two-dimensional material saved by the signal detection unit, it solves it and displays the solution result in real time. The present invention can realize the characteristic measurement of two-dimensional materials, and has the advantages of non-contact, non-destructive, and in-situ real-time measurement.

Description

Technical Field

[0001] The present invention relates to the fields of optical trap sensing and material science, and in particular to an in-situ real-time measurement device for two-dimensional materials and an application method thereof. Background Art

[0002] Since 2004, when Geim, Novoselov, and their colleagues first reported the mechanical fracture of atomically thin single-crystalline carbon films (graphene) and their remarkable transport properties, they have sparked a resurgence in a fascinating class of functional nanomaterials: two-dimensional materials. Two-dimensional materials, such as nanofilms, superlattices, and quantum wells, are materials in which electrons can move freely (in-plane) only in two dimensions, at the nanoscale (1-100 nm). These materials exhibit a host of unique properties, as both carrier migration and heat diffusion are confined within the two-dimensional plane. Their tunable band gap has broad applications in fields such as field-effect transistors, optoelectronics, and thermoelectrics. Their controllable spin and valley degrees of freedom have garnered intensive research in spintronics and valleytronics. Due to the unique properties of their crystal structures, different two-dimensional materials exhibit varying anisotropies in electrical and optical properties, including Raman spectroscopy, photoluminescence spectroscopy, second-order harmonic generation, optical absorption spectroscopy, thermal conductivity, and electrical conductivity. These properties hold great potential for development in polarized optoelectronic devices, polarized thermoelectric devices, biomimetic devices, and polarized light detection. Furthermore, sensors based on two-dimensional materials have broad applications in biomedicine.

[0003] The existing two-dimensional material measurement methods mainly include atomic force microscopy, transmission electron microscopy, and reflection differential spectroscopy. Atomic force microscopy can accurately measure the thickness information of two-dimensional materials; transmission electron microscopy can measure the structure and morphology information of two-dimensional materials; and reflection differential spectroscopy can measure the optical anisotropic characteristics of two-dimensional materials. Although the above measurement methods have their own advantages when measuring two-dimensional materials, the above two-dimensional material measurement methods are usually based on peeling the two-dimensional material to be measured and growing it on the surface of a silicon substrate, and then measuring the two-dimensional material, which inevitably introduces errors caused by the substrate in the test. In addition, when studying the changes in the properties of two-dimensional materials with changing environmental conditions, multiple measurements are usually required, that is, after completing a measurement, the two-dimensional material needs to be transferred from the measuring instrument to certain specific environments until it is transferred to the measuring instrument again when it is measured again. This will make the operation complicated and the change process of the two-dimensional material cannot be measured in real time. Therefore, it is necessary to explore new two-dimensional material measurement devices and methods to achieve in-situ real-time measurement of two-dimensional materials. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention proposes an in-situ real-time measurement device for two-dimensional materials and an application method thereof.

[0005] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0006] An in-situ real-time measurement device for two-dimensional materials, comprising a sample delivery unit, a light trap capture unit, a signal detection unit, a sample chamber, a signal resolution unit, and a sample chamber environmental condition control unit;

[0007] The sample delivery unit is used to load the two-dimensional material to be tested and transfer it to the sample chamber;

[0008] The light trap capturing unit is used to generate a light trap and capture the two-dimensional material in the sample chamber;

[0009] The signal detection unit is used to collect and store the Raman spectrum signal of the two-dimensional material captured by the light trap capture unit; the signal detection unit is provided with a Raman spectrometer;

[0010] The signal calculation unit is used to identify and calculate the Raman spectrum signal of the two-dimensional material stored in the signal detection unit;

[0011] The sample chamber environmental condition control unit is used to control the environmental conditions in the sample chamber.

[0012] The sample delivery unit comprises an electric translation stage and an optical fiber; the electric translation stage controls the nanometer-level displacement of the optical fiber on the electric translation stage.

[0013] The light trap capturing unit is a vertically suspended light trap in an atmospheric environment.

[0014] The signal detection unit includes a Raman spectrometer and a notch filter. A computer program is written to adaptively adjust the Raman scattered light characteristics of the two-dimensional material to control the size of the spectrometer entrance slit and the installation angle of the notch filter, thereby achieving high-resolution detection of the Raman spectrum signal of the two-dimensional material.

[0015] The signal solving unit is provided with a computer, which is used to write a program that can adaptively adjust according to experimental conditions and Raman spectrum signal characteristics, to automatically identify and solve the two-dimensional material Raman spectrum signal stored in the signal detection unit, and display the solution results in real time on the computer interface.

[0016] The sample chamber environmental condition control unit controls the relative humidity of the sample chamber from 0 to 100% by introducing dry nitrogen and / or wet nitrogen into the sample chamber.

[0017] An application method according to the device comprises the following steps:

[0018] 1) Load the two-dimensional material to be tested into the sample delivery unit;

[0019] 2) Turn on the laser of the light trap capture unit to form a light trap in the sample chamber;

[0020] 3) transferring the two-dimensional material of the sample delivery unit into the optical trap of the optical trap capture unit;

[0021] 4) Using the sample chamber environmental condition control unit to control the environmental conditions of the sample chamber, including relative humidity and ozone concentration;

[0022] 5) Collecting the Raman spectrum signal of the two-dimensional material into the signal detection unit and saving it;

[0023] 6) After the signal calculation unit recognizes the Raman spectrum signal of the two-dimensional material stored in the signal detection unit, it performs calculation and displays the calculation result in real time on the computer interface.

[0024] The two-dimensional material refers to a material in which electrons can only move freely in a two-dimensional plane at a scale of 1-100 nanometers. The two-dimensional material to be measured is captured by suspending it in an optical trap to achieve in-situ real-time measurement of the two-dimensional material.

[0025] The present invention has the following beneficial effects: The method utilizes a light trap to suspend and capture the two-dimensional material under test. By controlling the relative humidity and ozone concentration of the sample chamber where the two-dimensional material resides, the material's properties can be measured. This method offers the advantages of non-contact, non-destructive, and in-situ real-time measurement of the two-dimensional material under test. The device is simple, allowing users to easily add components to the optical path to expand its application capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of an in-situ real-time measurement device for two-dimensional materials.

[0027] Figure 2 This is a flow chart of the application method of the in-situ real-time measurement device based on two-dimensional materials.

[0028] Figure 3 Flowchart for computer-automated calculation of Raman spectral signals of two-dimensional materials.

[0029] In the figure, there are a sample delivery unit 1, a light trap capture unit 2, a signal detection unit 3, a sample chamber 4, a signal resolution unit 5 and a sample chamber environmental condition control unit 6. DETAILED DESCRIPTION

[0030] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0031] like Figure 1 As shown, a two-dimensional material in-situ real-time measurement device includes a sample delivery unit 1, a light trap capture unit 2, a signal detection unit 3, a sample chamber 4, a signal resolution unit 5 and a sample chamber environmental condition control unit 6;

[0032] The sample delivery unit 1 is used to load the two-dimensional material to be tested and transfer it to the sample chamber 4;

[0033] The light trap capturing unit 2 is used to generate a light trap and capture the two-dimensional material in the sample chamber 4;

[0034] The signal detection unit 3 is used to collect and store the Raman spectrum signal of the two-dimensional material captured by the light trap capture unit 2; the signal detection unit 3 is provided with a Raman spectrometer;

[0035] The signal calculation unit 5 is used to identify and calculate the Raman spectrum signal of the two-dimensional material stored in the signal detection unit 3;

[0036] The sample chamber environmental condition control unit 6 is used to control the environmental conditions in the sample chamber 4 .

[0037] The sample delivery unit 1 includes an electric translation stage and an optical fiber; the optical fiber is mounted on the electric translation stage; the electric translation stage can precisely control the nanometer-level displacement of the optical fiber on the electric translation stage through computer programming.

[0038] The light trap capture unit 2 is a vertically suspended light trap in an atmospheric environment. Compared to capturing a two-dimensional material in a liquid, such as water, capturing it in air is more difficult for three main reasons: First, the maximum numerical aperture (NA) of an objective lens achievable in air (approximately 1) is significantly smaller than that in water (NA approximately 1.33), resulting in a smaller light trapping force. Second, the faster Brownian motion of the particle sample in air (due to the lower viscosity of air than water) increases the probability of escape of the trapped sample. Third, the refractive index mismatch between glass and air not only reduces optical resolution but also the capture capability of the light trap. When capturing a sample in air using a light trap, the sample is typically sprayed into the sample chamber in the form of a spray. The sample's motion within the sample chamber is relatively fast and its trajectory is uncertain. Capture by the light trap is possible only when the sample slowly drifts through the effective capture area of ​​the light trap. At the same time, due to the large number of test samples injected at once, the test samples captured in the light trap are often knocked away by passing samples, resulting in low capture efficiency and poor capture stability. To avoid this problem, the device uses a motorized translation stage in the sample delivery unit 1. Through program-precise nanometer-scale control of the translation stage, the two-dimensional material to be tested, loaded onto the optical fiber on the translation stage, is directed to the light trap position in the light trap capture unit 2. Under the action of the light trap force, the two-dimensional material to be tested is stably bound to the center of the light trap. This effectively improves the success rate of the light trap capturing the two-dimensional material to be tested, thereby improving experimental efficiency.

[0039] The signal detection unit 3 comprises a Raman spectrometer and a notch filter. The scattered light signal from the two-dimensional material under test is typically composed of two components: the Rayleigh scattered light signal and the Raman scattered light signal. The notch filter effectively removes the Rayleigh scattered light signal, retaining the Raman scattered light signal and collecting it for entry into the Raman spectrometer's entrance slit. Furthermore, a computer program is written that adaptively adjusts the size and morphological characteristics of the Raman scattered light from the two-dimensional material under test to control the size of the spectrometer's entrance slit and the installation angle of the notch filter. This ensures that the Raman scattered light, after passing through the notch filter, is collimated and fully enters the spectrometer's entrance slit, thereby achieving high-resolution detection of the two-dimensional material's Raman spectral signal.

[0040] The signal analysis unit 5 includes a computer. A program is written on the computer that can adaptively adjust according to the experimental conditions and the characteristics of the Raman spectrum signal. The computer can automatically identify and analyze the Raman spectrum signal of the two-dimensional material stored in the signal detection unit 3, and display the analysis results (such as the number of layers of the two-dimensional material, etc.) in real time on the computer interface.

[0041] The sample chamber environmental condition control unit 6 can achieve 0-100% control of the relative humidity conditions in the sample chamber by introducing dry nitrogen and / or wet nitrogen into the sample chamber 4. The inflow of dry and wet nitrogen flow into the sample chamber can not only achieve the control of the relative humidity conditions in the sample chamber, but also discharge the radiant heat generated by long-term laser irradiation in the light trap out of the sample chamber.

[0042] An application method according to the device, the flow chart is as follows Figure 2 As shown, the following steps are included:

[0043] 1) Loading the two-dimensional material to be tested into the sample delivery unit 1;

[0044] 2) Turning on the laser of the light trap capture unit 2 to form a light trap in the sample chamber 4;

[0045] 3) transferring the two-dimensional material of the sample delivery unit 1 to the light trap of the light trap capture unit 2;

[0046] 4) Using the sample chamber environmental condition control unit 6 to control the environmental conditions of the sample chamber 4 (such as relative humidity, ozone concentration, etc.);

[0047] 5) collecting the Raman spectrum signal of the two-dimensional material into the signal detection unit 3 and storing it;

[0048] 6) After the signal solving unit 5 recognizes the Raman spectrum signal of the two-dimensional material stored in the signal detection unit 3, it automatically solves it and displays the solution result in real time on the computer interface.

[0049] The application method captures the two-dimensional material to be measured through light trap suspension, which can realize in-situ real-time measurement of the two-dimensional material. The in-situ real-time measurement of the two-dimensional material can ensure the measurement at the same position of the same sample, with high accuracy and good real-time performance.

[0050] Example 1

[0051] This embodiment 1 takes the light trapping unit capturing a two-dimensional material black phosphorus sample and performing in-situ real-time measurement on the sample as an example.

[0052] The laser used in the optical trap capture unit utilizes a 532nm fiber-coupled solid-state laser. The laser output power is continuously adjustable during implementation, meaning the optical power required to form the three-dimensional optical trap can be continuously adjusted to capture black phosphorus of varying sizes. The motorized translation stage utilizes a Thorlabs three-axis motorized translation stage.

[0053] The light trapping power is adjustable from 30 to 600 mW.

[0054] The brand of the spectrometer in the signal detection unit is Andor Shamrock 750.

[0055] The built-in space of the sample chamber is 50 cm 3 .

[0056] The in-situ real-time measurement method of the two-dimensional material black phosphorus of the present invention specifically comprises the following steps:

[0057] 1) Loading the two-dimensional material black phosphorus to be tested into the sample delivery unit 1, specifically by placing the black phosphorus on one end of an optical fiber on the motorized translation stage of the sample delivery unit under an optical microscope;

[0058] 2) Turning on the laser of the light trap capture unit 2 to form a light trap in the sample chamber 4 for capturing the two-dimensional material black phosphorus to be measured;

[0059] 3) By controlling the movement of the motorized translation stage through a program, the black phosphorus on the optical fiber is moved, thereby transferring the black phosphorus from the sample delivery unit 1 to the light trap of the light trap capture unit 2. In other words, the black phosphorus at one end of the optical fiber is precisely transferred to the capture center of the light trap.

[0060] 4) Using the flow controller in the sample chamber environmental condition control unit 6 to control the total amount of dry nitrogen and wet nitrogen entering the sample chamber 4, thereby adjusting the relative humidity of the sample chamber 4 to 70%;

[0061] 5) collecting the Raman spectrum signal of black phosphorus into the Raman spectrometer of the signal detection unit 3 and storing it;

[0062] 6) After the signal calculation unit 5 recognizes the black phosphorus Raman spectrum signal stored in the signal detection unit 3, it automatically calculates it and displays the calculation result on the computer interface in real time. The calculation process is as follows: Figure 3 shown.

[0063] Example 2

[0064] This embodiment 2 takes the light trapping unit capturing a two-dimensional material molybdenum disulfide sample and performing in-situ real-time measurement on the sample as an example.

[0065] The optical trap capture unit uses a 532nm fiber-coupled solid-state laser. The laser output power is continuously adjustable during implementation, meaning the optical power required to form the three-dimensional optical trap can be continuously adjusted to capture molybdenum disulfide (MoS2) of varying sizes. The motorized translation stage uses a Thorlabs three-axis motorized translation stage.

[0066] The light trapping power is adjustable from 30 to 600 mW.

[0067] The brand of the spectrometer in the signal detection unit is Andor Shamrock 750.

[0068] The built-in space of the sample chamber is 50 cm 3 .

[0069] The in-situ real-time measurement method of the two-dimensional material molybdenum disulfide of the present invention specifically comprises the following steps:

[0070] 1) Loading the two-dimensional material to be tested, molybdenum disulfide, into the sample delivery unit 1, specifically by placing the molybdenum disulfide at one end of an optical fiber on the motorized translation stage of the sample delivery unit under an optical microscope;

[0071] 2) Turning on the laser of the light trap capture unit 2 to form a light trap in the sample chamber 4 for capturing the two-dimensional material molybdenum disulfide to be measured;

[0072] 3) By controlling the movement of the motorized translation stage through a program, the molybdenum disulfide on the optical fiber is moved, thereby transferring the molybdenum disulfide from the sample delivery unit 1 to the light trap of the light trap capture unit 2. In other words, the molybdenum disulfide at one end of the optical fiber is precisely transferred to the capture center of the light trap;

[0073] 4) Using the flow controller in the sample chamber environmental condition control unit 6 to control the total amount of dry nitrogen and wet nitrogen entering the sample chamber 4, thereby adjusting the relative humidity of the sample chamber 4 to 60%;

[0074] 5) collecting the Raman spectrum signal of molybdenum disulfide into the Raman spectrometer of the signal detection unit 3 and storing it;

[0075] 6) After the signal solving unit 5 recognizes the Raman spectrum signal of molybdenum disulfide stored in the signal detection unit 3, it automatically solves it and displays the solution result on the computer interface in real time.

[0076] Finally, it should be noted that the above embodiments and explanations are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. It should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention may be made without departing from the spirit and scope of the technical solutions disclosed herein, and all such modifications or equivalent substitutions shall be encompassed within the scope of protection of the claims of the present invention.

Claims

1. A two-dimensional material in-situ real-time measurement device, characterized in that: It includes a sample delivery unit (1), a light trap capture unit (2), a signal detection unit (3), a sample chamber (4), a signal resolution unit (5) and a sample chamber environmental condition control unit (6); The sample delivery unit (1) is used to load the two-dimensional material to be tested and transfer it to the sample chamber (4); The light trap capturing unit (2) is used to generate a light trap and capture the two-dimensional material in the sample chamber (4); The signal detection unit (3) is used to collect and store the Raman spectrum signal of the two-dimensional material captured by the light trap capture unit (2); the signal detection unit (3) is provided with a Raman spectrometer; The signal calculation unit (5) is used to identify and calculate the Raman spectrum signal of the two-dimensional material stored in the signal detection unit (3); The sample chamber environmental condition control unit (6) is used to control the environmental conditions in the sample chamber (4); The sample delivery unit (1) comprises an electric displacement stage and an optical fiber; the electric displacement stage controls the nanometer-level displacement of the optical fiber on the electric displacement stage; The light trap capturing unit (2) is a vertically suspended light trap in an atmospheric environment.

2. The device according to claim 1, characterized in that The signal detection unit (3) includes a Raman spectrometer and a notch filter. A computer program is written to adaptively adjust the Raman scattering light characteristics of the two-dimensional material to control the size of the spectrometer entrance slit and the installation angle of the notch filter, thereby achieving high-resolution detection of the Raman spectrum signal of the two-dimensional material.

3. The device according to claim 1, characterized in that The signal solving unit (5) is provided with a computer, and a program is written on the computer that can be adaptively adjusted according to the experimental conditions and the Raman spectrum signal characteristics, so as to automatically identify and solve the two-dimensional material Raman spectrum signal stored in the signal detection unit (3), and display the solution result in real time on the computer interface.

4. The device according to claim 1, characterized in that The sample chamber environmental condition control unit (6) controls the relative humidity of the sample chamber (4) within a range of 0-100% by introducing dry nitrogen and / or wet nitrogen into the sample chamber (4).

5. A method for using the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) Loading the two-dimensional material to be tested into the sample delivery unit (1); 2) turning on the laser of the light trap capture unit (2) to form a light trap in the sample chamber (4); 3) transferring the two-dimensional material of the sample delivery unit (1) into the light trap of the light trap capture unit (2); 4) using the sample chamber environmental condition control unit (6) to control the environmental conditions of the sample chamber (4), including relative humidity and ozone concentration; 5) collecting the Raman spectrum signal of the two-dimensional material into the signal detection unit (3) and saving it; 6) After the signal solving unit (5) identifies the Raman spectrum signal of the two-dimensional material stored in the signal detection unit (3), it solves the signal and displays the solution result on the computer interface in real time.

6. The application method according to claim 5, characterized in that The two-dimensional material refers to a material in which electrons can only move freely in a two-dimensional plane at a scale of 1-100 nanometers. The two-dimensional material to be measured is captured by suspending it in an optical trap to achieve in-situ real-time measurement of the two-dimensional material.

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