Multifunctional micro-spectrum test system with adjustable test temperature and pressure

Abstract

The invention discloses a multifunctional micro-spectrum test system with adjustable test temperature and pressure, and belongs to the technical field of spectrum detection. Functions of an absorption spectrograph, a fluorescence spectrograph, a Raman spectrograph and a photoluminescence excitation spectrograph are integrated into one set of equipment, so that samples are not required to be transferred for multiple times at the same position, only the positions of part of parts in a test system need to be finely adjusted, and related test parameters are set; the Raman spectrum, the reflection / absorption spectrum, the fluorescence spectrum and the photoluminescence excitation spectrum of the sample can be obtained. Furthermore, through a test environment control subsystem, the temperature and the pressure of the test environment can be continuously and accurately adjusted, and the gas atmosphere can be changed according to requirements, so that not only can the sample be protected from denaturation in the test process, but also different samples can be ensured to be tested in the same test environment, and the test efficiency is improved. And the surface of the sample is not frozen in the low-temperature testing process, so that the testing result is more accurate and reliable.

Description

Technical Field

[0001] The present invention relates to a multifunctional microscopic spectroscopy test system with adjustable test temperature and pressure, and belongs to the technical field of spectral detection. Background Technique

[0002] Spectroscopy is an important interdisciplinary subject mainly involving physics and chemistry. By studying the interaction between electromagnetic waves and matter through spectra, it is the simplest and most effective method and means for qualitative and quantitative characterization of materials in modern scientific research. With the continuous in-depth of scientific research, the customization of material structure and performance becomes possible, and the continuous emergence of new materials has put forward more and more stringent requirements for the test environment and equipment performance. Therefore, spectral test equipment also needs to be continuously updated and iterated.

[0003] At present, most of the spectral test instruments on the market are single-functional, such as absorption spectrometers, fluorescence spectrometers, Raman spectrometers, etc. This leads to the need to test a substance structure on multiple different functional instrument devices to complete the full set of qualitative, quantitative characterization and optoelectronic performance analysis, which is not only time-consuming and laborious, but also the spectral characterization equipment is generally expensive, which will undoubtedly cause a large amount of resource waste. Taking the characterization of single-walled carbon nanotubes as an example, it is necessary to characterize its diameter, conductivity type, amorphous carbon and defect content through Raman spectroscopy; to characterize its diameter, purity and the content of metallic single-walled carbon nanotubes through optical (ultraviolet / visible / near-infrared) absorption spectroscopy; to characterize the chiral index and relative mass fraction of semiconducting single-walled carbon nanotubes through near-infrared photoluminescence spectroscopy, and to test the resistivity of carbon nanotubes by the four-probe method.

[0004] The Chinese patent with publication number CN117538264A discloses a multifunctional spectral photoelectric testing system, which realizes a variety of spectral photoelectric tests of linear polarization and circular polarization by integrating an adjustable power polarization light source module, a signal generation and synchronous observation module, and a signal receiving and detection module, specifically including Raman spectroscopy, photoluminescence spectroscopy, photoelectric detection and photovoltaic testing; however, the light source module of the system only includes lasers of different wavelengths as the excitation light source of the substance to be tested, so it can only realize the test of laser spectrum with laser as excitation light (such as Raman spectroscopy, photoluminescence spectroscopy), and cannot complete the spectral test that requires continuous wavelength light excitation (such as absorption spectrum, transmission / reflection spectrum), and does not consider the influence of environmental factors (such as temperature, humidity, pressure, etc.) on the test process and the sample itself; the Chinese patent with publication number CN1175538264A discloses a multifunctional spectral photoelectric testing system, which realizes a variety of spectral photoelectric tests of linear polarization and circular polarization, specifically including Raman spectroscopy, photoluminescence spectroscopy, photoelectric detection and photovoltaic testing; however, the light source module of the system only includes lasers of different wavelengths as the excitation light source of the substance to be tested, so it can only realize the test of laser spectrum with laser as excitation light (such as Raman spectroscopy, photoluminescence spectroscopy), and cannot complete the spectral test that requires continuous wavelength light excitation (such as absorption spectrum, transmission / reflection spectrum), and does not consider the influence of environmental factors (such as temperature, humidity, pressure, etc.) on the test process and the sample itself to be tested; the Chinese patent with publication number CN11755 The Chinese patent No. 4342A provides a multifunctional integrated compact microscopic optical path spectroscopy system, which includes a fixed optical system area and an open and expandable functional area. The fixed optical system area is used to perform low-temperature / variable temperature steady-state fluorescence spectroscopy, low-temperature / variable temperature Raman spectroscopy, and low-temperature / variable temperature time-resolved fluorescence spectroscopy microscopic optical path spectroscopy measurements. The open and expandable functional area realizes the measurement of low-temperature / variable temperature reflection / absorption spectroscopy and low-temperature / variable temperature photoluminescence excitation spectroscopy of the microscopic optical path by introducing a broadband excitation light source, and can extend the temperature range to 3.3-700K, perform low-temperature / variable temperature nonlinear fluorescence spectroscopy caused by double / single photon absorption, and ultrafast spectroscopy measurement based on pump-probe. However, it does not consider the influence of environmental factors (such as temperature, humidity, pressure, etc.) on the test process and the sample itself. Although the solutions of the above two patents have achieved the integration of spectral detection technology to a certain extent, their test environment is still the same as the single-function spectral test instruments on the market, all of which are room temperature and atmospheric environment. Therefore, the impact of the test environment on the sample itself is not considered, such as oxidation, moisture, hydrolysis, etc. of the material, and some temperature and pressure sensitive materials. When the test environment changes, their own properties will also change accordingly. For example, metallic sodium, red phosphorus, anhydrous copper sulfate, etc., due to the presence of oxygen and water vapor in the air, these substances will undergo different degrees of oxidation, hydrolysis and moisture absorption, etc., and will be damaged and failed during the process of conducting different types of characterization tests, as well as during the storage and transfer of samples. In addition, the photoelectric properties of some substances will also change at different temperatures (such as molybdenum disulfide crystals). Existing spectral characterization equipment cannot control the temperature of the test environment, and often needs to be equipped with a high and low temperature test bench to perform variable temperature testing, which increases the complexity of the test. Moreover, due to the atmospheric environment, during the low-temperature experiment, the water vapor in the air will inevitably condense and freeze on the sample surface, thereby affecting the test results. Summary of the invention

[0005] To solve the existing problems, the present invention provides a multifunctional microscopic spectroscopy test system with adjustable test temperature and pressure, comprising a multifunctional microscopic spectroscopy test subsystem and a test environment control subsystem; wherein, the multifunctional microscopic spectroscopy test subsystem is used to excite the sample and collect optical signals, and can complete the collection of Raman spectrum, fluorescence spectrum, photoluminescence spectrum, reflection spectrum and absorption spectrum of the sample without moving the sample, and the test environment control subsystem is used to maintain the temperature, pressure and gas atmosphere of the surrounding environment of the sample during the test.

[0006] Optionally, the multifunctional microscopic spectroscopy test subsystem includes three light sources, four reflectors, three guide rails, two transmissive-reflective mirrors, three optical baffles, one microscopic objective lens, one sample stage, one imaging camera, two spectroscopic spectrometers, one attenuation filter, one polarizer, one dichroic mirror, two condenser lenses and one CCD detector; wherein, the three light sources include an illumination light source, a broadband tunable light source and a laser light source. The illumination light source is used to provide stable, uniform and sufficiently bright light when the system realizes the functions of observing the sample and finding the test position on the sample, ensuring that the details and features on the surface of the sample are fully exposed and providing a basis for subsequent observation and analysis. The broadband tunable light source is used to provide light of a specific wavelength as the excitation light when the system realizes the functions of reflection spectrum test, absorption spectrum test and photoelectric response test. The laser light source is used to provide light of a specific wavelength as the excitation light when the system realizes the functions of Raman spectrum test, fluorescence spectrum test and photoluminescence spectrum test.

[0007] Optionally, the four reflectors are used to change the optical path direction, and the three guide rails are used to adjust the positions of the corresponding transmissive-reflective mirrors, reflectors and dichroic mirrors; the optical baffle is used to isolate and block light; the microscopic objective lens is used to converge light onto the surface of the sample and observe the surface of the sample; the sample stage is used to carry the sample to be tested; the imaging camera is used to capture and record the image of the sample morphology under the microscope when the system realizes the microscopic imaging function; the spectroscopic spectrometer is used to disperse the composite light so that light of different wavelengths is separated into different directions; the attenuation filter and the polarizer are used to convert the laser output by the laser light source into a laser with a specific power and polarization angle; the dichroic mirror is used to filter the signals of the laser corresponding wavelength and its adjacent wavelengths and only transmit the effective optical signals containing the sample information; the condenser lens is used to converge the incident light onto a smaller area; the CCD detector is used to capture light signals of different wavelengths, convert them into electrical signals and display them in the form of spectra.

[0008] Optionally, the multi-functional microscopic spectroscopy test subsystem includes an illumination light source 1, a first reflecting mirror 2, a first guide rail 3, a first transmissive and reflective mirror 4, a second reflecting mirror 5, a first optical baffle 6, a microscopic objective 7, a sample stage 8, an imaging camera 9, a broadband tunable light source 10, a first spectroscopic spectrometer 11, a second transmissive mirror 12, a second optical baffle 13, a second guide rail 14, a laser light source 15, an attenuation filter 16, a polarizer 17, a third optical baffle 18, a third guide rail 19, a dichroic mirror 20, a third reflecting mirror 21, a fourth reflecting mirror 22, a first condenser 23, a second condenser 24, a second spectroscopic spectrometer 25, and a CCD detector 26; Wherein, the first transmissive and reflective mirror 4 and the second reflecting mirror 5 are fixed on the first guide rail 3; When observing the microscopic morphology of a sample, move the first transmissive and reflective mirror 4 and the second reflecting mirror 5 along the first guide rail 3 so that the first transmissive and reflective mirror 4 is aligned with the microscopic objective 7. The illumination light emitted by the illumination light source 1 passes through the first reflecting mirror 2 and the first transmissive and reflective mirror 4, and then is emitted by the microscopic objective 7. At this time, the second reflecting mirror 5 and the first optical baffle 6 do not work; When collecting spectra, adjust the optical path to introduce the corresponding excitation light into the microscopic objective 7 and shield the illumination light. Move the first transmissive and reflective mirror 4 and the second reflecting mirror 5 along the first guide rail 3 so that the second reflecting mirror 5 is aligned with the microscopic objective 7. At this time, the illumination light passes through the first reflecting mirror 2 and the first transmissive and reflective mirror 4 and then irradiates on the first optical baffle 6.

[0009] Optionally, the second transmissive mirror 12 is fixed on the second guide rail 14; When a broadband composite white light is required as the excitation light source, move the second transmissive mirror 12 along the second guide rail 14 so that it is aligned with the second reflecting mirror 5. At this time, the composite white light emitted by the broadband tunable light source 10 is reflected by the second transmissive mirror 12 and the second reflecting mirror 5 and then is emitted by the microscopic objective 7. At this time, the second optical baffle 13 does not work; When a composite white light is not required as the excitation light source, move the second transmissive mirror 12 along the second guide rail 14 so that it is aligned with the second optical baffle 13, and make the composite white light irradiate on the second optical baffle 13.

[0010] Optionally, the dichroic mirror 20 is fixed on the third guide rail 19; When a laser is required as the excitation light source, move the dichroic mirror 20 along the third guide rail 19 so that it is aligned with the second reflecting mirror 5. At this time, the laser emitted by the laser light source 15 is reflected by the dichroic mirror 20 and the second reflecting mirror 5 and then is emitted by the microscopic objective 7. At this time, the third optical baffle 18 does not work; When a laser is not required as the excitation light source, move the dichroic mirror 20 along the third guide rail 19 so that it is aligned with the third optical baffle 18, and make the laser irradiate on the third optical baffle 18.

[0011] Optionally, the test environment control subsystem includes a sample stage 8, a cylinder gas 27, a vacuum pump 35, a cryogenic liquid bottle 36, and a gas pipeline 37; wherein, the sample stage 8 is a sealable chamber, and the cylinder gas 27, the cryogenic liquid bottle 36, and the vacuum pump 35 are all connected to the sample stage 8.

[0012] Optionally, four metal probes for testing the photoelectric response of the sample are arranged in the chamber of the sample stage 8. A first air vent 8.1 and a second air vent 8.2 are arranged on both sides of the sample stage 8, and a light-transmitting glass window 8.15 is arranged directly above.

[0013] Optionally, a pressure reducing valve 28, a stop valve 29, a pressure gauge 30, and a vacuum gauge 31 are arranged on the gas pipeline connecting the cylinder gas 27 and the sample stage 8. The cryogenic liquid bottle 36 is directly connected to the sample stage 8, and the vacuum pump 35 is connected to the sample stage 8 through a ball valve 34.

[0014] The present application also provides an application of the above-mentioned multi-functional microscopic spectroscopy test system with adjustable test temperature and pressure in the field of spectral detection technology.

[0015] The beneficial effects of the present invention are as follows: By designing a set of multi-functional microscopic spectroscopy test system, the functions of an absorption spectrometer, a fluorescence spectrometer, a Raman spectrometer, and a photoluminescence excitation spectrometer are integrated into a set of equipment, realizing that at the same position, without multiple sample transfers, only by slightly adjusting the positions of some components in the test system and setting relevant test parameters, the Raman spectrum, reflection / absorption spectrum, fluorescence spectrum, and photoluminescence excitation spectrum of the sample can be obtained. Further, the solution of the present application also designs a set of test environment control system, which is used in combination with the above-mentioned multi-functional microscopic spectroscopy test system, realizing continuous and precise adjustment of the temperature and pressure of the test environment, and the gas atmosphere can be changed according to requirements; it can not only protect the sample from being deformed during the test, but also ensure that different samples are tested under the same test environment, and the surface of the sample will not freeze during the low-temperature test, thereby making the measurement results more accurate and reliable. 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 the description of the embodiments. 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 be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the composition of the multi-functional microscopic spectroscopy test subsystem in the multi-functional microscopic spectroscopy test system with adjustable test temperature and pressure provided by an embodiment of the present invention.

[0018] Figure 2 It is a schematic diagram of the optical path of the system when laser is used as the excitation light in the multi-functional microscopic spectroscopy test subsystem provided by an embodiment of the present invention.

[0019] Figure 3 It is a schematic diagram of the optical path of the system when composite white light is used as the excitation light in the multi-functional microscopic spectroscopy test subsystem provided by an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of the optical path for collecting the absorption spectrum of the sample in the multi-functional microscopic spectroscopy test subsystem provided by an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of the connection relationship of the main components of the test environment control subsystem in the multi-functional microscopic spectroscopy test system with adjustable test temperature and pressure provided by an embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of the sample stage structure of the test environment control subsystem provided by an embodiment of the present invention.

[0023] Figure 7 It is the Raman spectrum of two-dimensional MoS 2 crystals measured by the multi-functional microscopic spectroscopy test system with adjustable test temperature and pressure provided by the present invention.

[0024] Figure 8 It is the variable-temperature fluorescence spectrum of two-dimensional MoS 2 crystals measured by the multi-functional microscopic spectroscopy test system with adjustable test temperature and pressure provided by the present invention.

[0025] Figure 9 It is the surface microscopic morphology diagram of the sample at different temperatures without using the test environment control subsystem under a scale of 10um.

[0026] Figure 10 It is the surface microscopic morphology diagram of the sample at different temperatures when using the test environment control subsystem under a scale of 10um.

[0027] Figure 11 It is the demonstration effect diagram of the composite white light splitting effect under a scale of 10um. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] Embodiment 1 This embodiment provides a multifunctional microscopic spectroscopy test system with adjustable test temperature and pressure, including a multifunctional microscopic spectroscopy test subsystem and a test environment control subsystem. The following is a separate introduction to the two subsystems: (1) Multifunctional microscopic spectroscopy test subsystem. This subsystem is mainly used to realize the excitation of samples and the acquisition of optical signals. It includes three light sources, four reflectors, three guide rails, two transmissive-reflective mirrors, three optical baffles, a microscopic objective lens, a sample stage, an imaging camera, two spectroscopic spectrometers, an attenuation filter, a polarizer, a dichroic mirror, two condenser lenses, and a CCD detector. Among them, the three light sources include an illumination light source, a broadband tunable light source, and a laser light source: The illumination light source is used to provide stable, uniform, and sufficiently bright light when the system realizes the functions of observing samples and finding the test positions on the samples, ensuring that the details and features on the sample surface are fully exposed, and providing a basis for subsequent observation and analysis.

[0030] The broadband tunable light source is used to provide light with a specific wavelength as the excitation light when the system realizes the functions of reflection spectroscopy test, absorption spectroscopy test, and photoelectric response test.

[0031] The laser light source is used to provide light with a specific wavelength as the excitation light when the system realizes the functions of Raman spectroscopy test, fluorescence spectroscopy test, and photoluminescence spectroscopy test.

[0032] The four reflectors are used to change the optical path direction. Among the three guide rails, the directions of two guide rails are the same and perpendicular to the direction of the other guide rail, which are used to adjust the positions of the first transmissive-reflective mirror, the second reflector, the second transmissive-reflective mirror, and the dichroic mirror. The optical baffle is used to isolate and block light. The microscopic objective lens is used to magnify and focus light. The sample stage is used to carry the sample to be tested. The imaging camera is used to capture and record the image of the sample morphology under the microscope when the system realizes the microscopic imaging function. The spectroscopic spectrometer is used to disperse the composite light so that light with different wavelengths is separated into different directions. The attenuation filter and the polarizer are used to convert the laser output by the laser light source into a laser with a specific power and polarization angle. The dichroic mirror is used to filter the signals of the laser corresponding wavelength and its adjacent wavelengths, and only transmit the effective optical signals containing sample information. The condenser lens is used to focus the incident light onto a smaller area. The CCD detector is used to capture light signals with different wavelengths, convert them into electrical signals, and display them in the form of spectra.

[0033] As Figure 1As shown in the figure, the subsystem consists of an illumination light source 1, a first reflector 2, a first guide rail 3, a first transmissive and reflective mirror 4, a second reflector 5, a first optical baffle 6, a microscope objective 7, a sample stage 8, an imaging camera 9, a broadband tunable light source 10, a first spectroscopic spectrometer 11, a second transmissive and reflective mirror 12, a second optical baffle 13, a second guide rail 14, a laser light source 15, an attenuation sheet 16, a polarizer 17, a third optical baffle 18, a third guide rail 19, a dichroic mirror 20, a third reflector 21, a fourth reflector 22, a first condenser 23, a second condenser 24, a second spectroscopic spectrometer 25, and a CCD detector 26. The entire spectral test system has a compact structure and diverse functions. By finely adjusting the positions of some of its components, the acquisition of Raman spectra, fluorescence spectra, photoluminescence spectra, reflection spectra, and absorption spectra of micro-regions of the sample can be realized respectively, as well as the optoelectronic response test of the sample to light of different wavelengths.

[0034] The broadband tunable light source 10 and the laser light source 15 serve as excitation light sources for different functional tests.

[0035] The broadband tunable light source 10 is a laser-driven white light source that can emit composite white light with a wavelength range of 170 - 2100 nm. The composite white light passes through the first spectroscopic spectrometer 11. Using the spectroscopic principle of the grating, the white light with a composite wavelength is independently separated after being diffracted by the grating. Then, light with a specific wavelength within the range of 170 - 2100 nm can be output as the excitation light. At the same time, in addition to the spectroscopic grating, a reflector is also installed in the first spectroscopic spectrometer 11. When grating spectroscopy is not required, the reflector is used to replace the grating and is connected to the internal optical path of the first spectroscopic spectrometer 11, and then composite white light can be output.

[0036] When the composite white light of the broadband tunable light source 10 is transmitted to the spectroscopic spectrometer through an optical fiber, using the spectroscopic principle of the grating, by controlling the rotation angle of the grating in the spectroscopic spectrometer through a computer, the white light with a composite wavelength can be independently separated after being diffracted by the grating, and then the light with a specific wavelength within the range of 170 - 2100 nm can be output by reflection of the reflector. The effect is as Figure 11 shown.

[0037] The laser emitted by the laser light source 15 passes through the attenuation sheet 16 and the polarizer 17, and then a laser with a specific power and polarization angle can be output as the excitation light.

[0038] The first transmissive and reflective mirror 4 and the second reflector 5 are fixed on the first guide rail 3 and can move within a certain range. When observing the microscopic morphology of the sample, the first transmissive and reflective mirror 4 and the second reflector 5 are moved along the first guide rail 3 so that the first transmissive and reflective mirror 4 is aligned with the microscope objective 7. The illumination light emitted by the illumination light source 1 passes through the first reflector 2 and the first transmissive and reflective mirror 4, and then is emitted by the microscope objective 7. At this time, the second reflector 5 and the first optical baffle 6 do not work, as Figure 1As shown. When collecting the spectrum, it is necessary to adjust the optical path to introduce the corresponding excitation light into the microscope objective 7 and shield the illumination light. Move the first beam splitter 4 and the second reflector 5 along the first guide rail 3 so that the second reflector 5 is aligned with the microscope objective 7. At this time, the illumination light is irradiated on the first optical baffle 6 after passing through the first reflector 2 and the first beam splitter 4, as Figure 2 shown.

[0039] The second beam splitter 12 is fixed on the second guide rail 14 and can be moved within a certain range. When a broadband composite white light is needed as the excitation light source, move the second beam splitter 12 along the second guide rail 14 to align it with the second reflector 5. At this time, the composite white light emitted by the broadband tunable light source 10 is reflected by the second beam splitter 12 and the second reflector 5 and then emitted by the microscope objective 7. The second optical baffle 13 does not work, as Figure 3 shown. When a composite white light is not needed as the excitation light source, move the second beam splitter 12 along the second guide rail 14 to align it with the second optical baffle 13, and make the composite white light irradiate on the second optical baffle 13, as Figure 1 shown in.

[0040] The dichroic mirror 20 is fixed on the third guide rail 19 and can be moved within a certain range. When a laser is needed as the excitation light source, move the dichroic mirror 20 along the third guide rail 19 to align it with the second reflector 5. At this time, the laser emitted by the laser light source 15 is reflected by the dichroic mirror 20 and the second reflector 5 and then emitted by the microscope objective 7. The third optical baffle 18 does not work, as Figure 2 shown. When a composite white light is not needed as the excitation light source, move the dichroic mirror 20 along the third guide rail 19 to align it with the third optical baffle 18, and make the laser irradiate on the third optical baffle 18, as Figure 1 shown.

[0041] Before the test, it is necessary to observe the microscopic morphology of the sample and find the specific test position on the sample. Place the sample on the sample stage 8, turn on the illumination light source 1, move the first beam splitter 4 and the second reflector 5 along the first guide rail 3 so that the first beam splitter 4 is aligned with the microscope objective 7. The illuminating white light passes through the first reflector 2 and the first beam splitter 4 and then is emitted by the microscope objective 7 for imaging. The information beam containing the optical image of the sample enters the imaging camera 9 after passing through the first beam splitter 4, and the imaging of the sample is completed. After finding a suitable test position on the sample, move the first beam splitter 4 and the second reflector 5 along the first guide rail 3 so that the second reflector 5 is aligned with the microscope objective 7, and prepare to start the optical test.

[0042] When collecting Raman spectra, fluorescence spectra, and photoluminescence spectra, a laser needs to be used as the excitation light source. Move the dichroic mirror 20 along the third guide rail 19 to align it with the second reflector 5. The laser emitted by the laser light source 15 passes through the attenuation sheet 16 and the polarizer 17, and then is reflected by the dichroic mirror 20 and the second reflector 5, and finally is emitted from the microscope objective 7 to the test position on the sample. The Raman signal / fluorescence signal / photoluminescence signal of the sample and the excitation light beam reflected from the sample surface pass through the microscope objective 7, are reflected by the second reflector 5, and then enter the dichroic mirror 20. The dichroic mirror 20 filters out the signals corresponding to the wavelength of the laser and its adjacent wavelengths, that is, removes the excitation light beam reflected from the sample surface, and only transmits the effective optical signal containing the sample information. The Raman signal / fluorescence signal of the sample is focused by the first condenser 23 and then enters the second spectroscopic spectrometer 25 for spectroscopy, and finally is detected by the CCD detector 26 to complete the test of the Raman signal / fluorescence signal / photoluminescence signal at the test position of the sample. As Figure 2 shown.

[0043] When performing reflection spectrum tests, a broadband composite white light needs to be used as the excitation light source. Move the second transmissive-reflective mirror 12 along the second guide rail 14 to align it with the second reflector 5. The composite white light emitted by the broadband tunable light source 10 passes through the second transmissive-reflective mirror 12 and the second reflector 5, and then is emitted from the microscope objective 7 to the test position on the sample. The reflection signals of the sample for different wavelengths of light pass through the microscope objective 7, are reflected by the second reflector 5, and then enter the second transmissive-reflective mirror 12. After being focused by the first condenser 23, they enter the second spectroscopic spectrometer 25 for spectroscopy, and finally are detected by the CCD detector 26 to complete the test of the reflection signal at the test position of the sample. As Figure 3 shown.

[0044] When performing transmission / absorption spectrum tests, a broadband composite white light needs to be used as the excitation light source. Move the second transmissive-reflective mirror 12 along the second guide rail 14 to align it with the second reflector 5. The composite white light emitted by the broadband tunable light source 10 passes through the second transmissive-reflective mirror 12 and the second reflector 5, and then is emitted from the microscope objective 7 to the test position on the sample. The optical signal containing the transmission / absorption information of the sample is emitted from the through hole reserved on the sample stage 8, is reflected by the third reflector 21 and the fourth reflector 22, and then is focused by the second condenser 24 and enters the second spectroscopic spectrometer 25 for spectroscopy, and finally is detected by the CCD detector 26 to complete the test of the transmission / absorption signal at the test position of the sample. As Figure 4 shown.

[0045] Four movable metal probes are installed on the sample stage 8. When electrodes are plated on the sample, the metal probes are moved to touch the electrodes. Then, the composite light emitted by the broadband tunable light source 10 is split by the above-mentioned first spectroscopic spectrometer 11, and light of a specific wavelength can be output. When the light irradiates the sample, the photon energy can be absorbed by the sample, and electrons are excited from the valence band to the conduction band, resulting in the appearance of free electrons (and holes) in the sample. If there is an external or internal electric field, these free carriers will form an electric current, that is, a photocurrent. By detecting the photocurrent, the photoelectric response information of the sample to light of different wavelengths can be obtained.

[0046] (2) Test environment control subsystem The test environment control subsystem is mainly used to maintain the temperature, pressure and gas atmosphere of the surrounding environment of the sample during the test. It is composed of a sample stage 8, a cylinder gas 27, a pressure reducing valve 28, a stop valve 29, a pressure gauge 30, a vacuum gauge 31, a first three-way pipe 32, a second three-way pipe 33, a ball valve 34, a vacuum pump 35, a cryogenic liquid bottle 36 and a gas pipeline 37, etc. The schematic diagram of the connection relationship of its main components is as Figure 5 shown in the figure; the cylinder gas 27, the cryogenic liquid bottle 36 and the vacuum pump 35 are all connected to the sample stage 8. Among them, a pressure reducing valve 28, a stop valve 29, a pressure gauge 30 and a vacuum gauge 31 are arranged on the gas pipeline connecting the cylinder gas 27 and the sample stage 8. The cryogenic liquid bottle 36 is directly connected to the sample stage 8, and the vacuum pump 35 is connected to the sample stage 8 through the ball valve 34. The sample stage 8 is a closable chamber, which is used to provide a suitable pressure and temperature environment for the sample to be tested.

[0047] The cylinder gas 27 stores high-pressure inert gas, which is used to maintain the gas atmosphere in the cavity of the sample stage 8; the cryogenic liquid bottle 36 stores cryogenic liquid, which is used to maintain the low-temperature environment in the cavity of the sample stage 8 during low-temperature / variable-temperature tests.

[0048] The pressure reducing valve 28 is installed at the outlet of the cylinder gas 27, which is used to adjust the pressure at the outlet of the cylinder gas 27; the stop valve 29 is used to switch the pipeline fluid, and can be adjusted and cut off according to the valve body opening; the ball valve 34 is used for the quick cut-off and flow path conversion of the flow path.

[0049] Both the pressure gauge 30 and the vacuum gauge 31 are used to display the air pressure value in the cavity of the sample stage in real time. The working range of the pressure gauge 30 is 0.1 - 1000 kPa, and the working range of the vacuum gauge 31 is 0.01 - 1000 Pa.

[0050] The vacuum pump 35 is used to pump out the gas in the cavity of the sample stage, and maintain a vacuum environment or an inert gas environment in the cavity of the sample stage 8.

[0051] All of the above components are connected by a stainless-steel gas pipeline 37 and the sealing performance is tested. After testing, with the stop valve 29 closed and the ball valve 34 opened, under the action of the vacuum pump 35, the pressure inside the cavity of the sample stage 8 can be reduced to below 1 Pa, and the gas leakage rate is less than 0.2 Pa / min; under the experimental conditions of introducing cylinder gas 27, by controlling the opening degrees of the stop valve 29 and the ball valve 34, pressure regulation and stabilization between 1 Pa and 200 kPa can be achieved. Before the test starts, close the stop valve 29, open the ball valve 34 and the vacuum pump 35, and evacuate the sealed cavity of the sample stage 8 to a high-vacuum state. At this time, the reading of the vacuum gauge 31 is the vacuum degree inside the cavity of the sample stage 8. Open the cylinder gas 27, adjust the outlet pressure through the pressure reducing valve 28, and slowly open the stop valve 29. At this time, the reading of the pressure gauge 30 is the pressure inside the cavity of the sample stage 8. The test can be started after the pressure inside the cavity rises to the target pressure value and stabilizes. It is verified that this method can effectively avoid the problem of ice formation on the surface of the sample during the low-temperature experiment.

[0052] The sample stage 8 is made of stainless steel, used for placing and fixing the sample to be tested, can be sealed, and four metal probes are arranged inside the cavity for testing the photoelectric response of the sample. As shown in Figure 6 Figure, there are a first vent 8.1 and a second vent 8.2 arranged on both sides of the sample stage 8, and there is a glass window 8.15 through which light can pass directly above.

[0053] The movement of the first probe is controlled by the first probe X-direction knob 8.3, the first probe Y-direction knob 8.4, and the first probe Z-direction knob 8.5; the movement of the second probe is controlled by the second probe X-direction knob 8.6, the second probe Y-direction knob 8.7, and the second probe Z-direction knob 8.8; the movement of the third probe is controlled by the third probe X-direction knob 8.9, the third probe Y-direction knob 8.10, and the third probe Z-direction knob 8.11; the movement of the fourth probe is controlled by the fourth probe X-direction knob 8.12, the fourth probe Y-direction knob 8.13, and the fourth probe Z-direction knob 8.14.

[0054] An electric heating circuit and a cryogenic liquid circuit are arranged in the sample stage 8. By controlling the magnitude of the current in the electric heating circuit and the cryogenic liquid in the cryogenic liquid circuit, the temperature control of the sealed cavity of the sample stage 8 is jointly achieved: When performing a high-temperature experiment, the electric heating circuit is powered on, and the temperature of the sample stage is increased through the electrothermal effect; When performing a low-temperature experiment, the cryogenic liquid flows through the cryogenic liquid circuit, and the heat inside the sample stage is taken away through the vaporization process, thereby achieving the effect of cooling.

[0055] After testing, the controllable temperature of this sample stage 8 is -190 °C (cooled by liquid nitrogen) to 400 °C, which can meet the variable-temperature tests of most laboratory-level and industrial-level. In theory, by replacing the cryogenic liquid with a lower temperature, such as liquid helium, the temperature can be reduced to a lower level.

[0056] Example 2 This embodiment provides a test method based on the multifunctional microscopic spectroscopy test system with adjustable test temperature and pressure provided in Example 1. Taking the Raman spectroscopy characterization of two-dimensional molybdenum disulfide (MoS 2 ) crystals grown on a silicon substrate as an example, the description is as follows: Using this system for Raman spectroscopy testing to qualitatively characterize the sample. Place the sample grown well on the silicon substrate in the center of the sample stage, turn on the microscopic illumination light source, adjust the focal length, find the area to be measured, which is a triangular thin sheet, turn on the 532nm laser light source, adjust the attenuation filter group to an appropriate laser intensity, and adjust the test parameters such as Raman wave number, integration time, and grating scale in the computer software, then the measurement can be started and the Raman spectrum can be obtained. After the test results are normalized, as Figure 7 shown. In Figure 7 , relatively obvious Raman characteristic peaks of MoS 2 and Si appear. Compared with the literature, the peak positions are accurate and the signal-to-noise ratio is high.

[0057] Example 3 This embodiment provides a test method based on the multifunctional microscopic spectroscopy test system with adjustable test temperature and pressure provided in Example 1. Taking the variable-temperature fluorescence spectroscopy characterization of two-dimensional MoS 2 crystals grown on a silicon substrate as an example, the description is as follows: Some studies have shown that two-dimensional MoS 2 crystals have a fluorescence peak at 1.82 eV, and this fluorescence peak will shift with the change of temperature. And when the temperature drops to a certain extent, a fluorescence peak will appear at about 2.0 eV. Use the multifunctional microscopic spectroscopy test system built by the present invention to perform fluorescence spectroscopy testing on two-dimensional MoS 2 crystals.

[0058] Place the sample grown well on the silicon substrate in the center of the sample stage, turn on the microscopic illumination light source, adjust the focal length, find the area to be measured, which is a triangular thin sheet. Then seal the sample stage, open the angle valve and use a vacuum pump to pump out the air in the cavity to prevent water in the air from condensing and adhering to the sample surface at low temperature, which may contaminate the sample and affect the test results. After the vacuum gauge shows a value below 1 Pa, open the gas cylinder gas switch (nitrogen in this experiment), use a pressure reducing valve to adjust the air pressure at the gas cylinder gas outlet to an appropriate value, slightly open the ball valve, and make the air pressure in the sample stage cavity stable at about 100 Pa, so that the sample is always protected in a nitrogen atmosphere, avoiding the influence of leaked air.

[0059] Use a computer to control the temperature inside the sample stage cavity. After the reading stabilizes, turn on the 532 nm laser light source, adjust the attenuation filter set to an appropriate laser intensity, and set test parameters such as the test range, integration time, and grating scale in the computer software. Then, you can start the measurement and obtain the fluorescence spectrum of the sample at the current temperature. After each single test, change the temperature inside the sample stage cavity. After the reading stabilizes, repeat the above test process. Finally, normalize the output spectral data and organize it into a single spectrum diagram, as Figure 8 shown.

[0060] In Figure 8 , a relatively obvious fluorescence characteristic peak of MoS 2 appears at point A, and the position of this peak gradually moves to the right as the temperature decreases, from 1.81 eV at 320 K to 1.87 eV at 80 K. At 320 K, no obvious fluorescence characteristic peak appears at point B. When the temperature gradually decreases to 200 K, a fluorescence characteristic peak appears, and the shape of this peak becomes more and more obvious as the temperature decreases. The fluorescence spectrum information obtained through this test system is basically consistent with that in the literature.

[0061] Example 4 To further illustrate the necessity of designing the test environment control subsystem in this application, the following is a comparison of the impact of using or not using the test environment control system on sample testing: (1)Cool the sample without using the test environment control system Place the sample grown on the silicon substrate in the center of the sample stage, turn on the microscopic illumination light source, adjust the focal length, and find the area to be tested, which is a triangular thin slice. Then seal the sample stage. At this time, both the ball valve and the angle valve are in the closed state, and the environment inside the sample stage cavity is air, with the pressure being the atmospheric pressure. When the temperature drops below 270 K, water inside the cavity begins to slowly condense and attach to the surface of the sample. As the temperature decreases and the experimental time extends, this phenomenon will become more and more serious. Eventually, a thick layer of substance will condense on the surface of the sample, as Figure 9 shown, seriously affecting subsequent testing.

[0062] (2)Cool the sample using the test environment control system Repeat the experimental process in (1) above. However, before cooling, open the angle valve and use a vacuum pump to evacuate the air inside the cavity to prevent water in the air from condensing and attaching to the surface of the sample at low temperatures, which may contaminate the sample and affect the test results. After the reading of the vacuum gauge drops below 1 Pa, open the gas cylinder gas switch (nitrogen in this experiment), use a pressure reducing valve to adjust the air pressure at the outlet of the gas cylinder to an appropriate value, slightly open the ball valve, and make the air pressure inside the sample stage cavity stable at about 100 Pa, so that the sample is always protected in a nitrogen atmosphere. Repeat the cooling process until the temperature inside the sample stage cavity drops to 80 K and is maintained for 10 min. No condensate is observed on the surface of the sample throughout the process, asFigure 10 as shown in

[0063] Some steps in the embodiments of the present invention can be implemented by software, and the corresponding software program can be stored in a readable storage medium, such as an optical disc or a hard disk, etc.

[0064] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A multifunctional microscopic spectrum testing system with adjustable test temperature and pressure, characterized in that: It includes a multifunctional micro-spectroscopy test subsystem and a test environment control subsystem; wherein the multifunctional micro-spectroscopy test subsystem is used to realize the excitation of the sample and the collection of the light signal, so as to complete the collection of the sample's Raman spectrum, fluorescence spectrum, photoluminescence spectrum, reflection spectrum and absorption spectrum without moving the sample; the test environment control subsystem is used to maintain the temperature, pressure and gas atmosphere of the environment surrounding the sample during the test.

2. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 1, characterized in that: The multifunctional microscopic spectrum test subsystem includes three light sources, four reflectors, three guide rails, two transflective mirrors, three optical baffles, a microscope objective, a sample stage, an imaging camera, two spectrometers, an attenuation plate, a polarizer, a dichroic mirror, two condensers and a CCD detector; wherein the three light sources include an illumination light source, a broadband adjustable light source and a laser light source, wherein the illumination light source is used to provide illumination light when the system realizes the functions of observing samples and finding test positions on samples; the broadband adjustable light source is used to provide light of a specific wavelength as excitation light when the system realizes the functions of reflection spectrum test, absorption spectrum test and photoelectric response test; and the laser light source is used to provide light of a specific wavelength as excitation light when the system realizes the functions of Raman spectrum test, fluorescence spectrum test and photoluminescence spectrum test.

3. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 2, characterized in that: Four reflectors are used to change the direction of the light path, and three rails are used to adjust the positions of the corresponding transflector, mirror and dichroic mirror; the optical baffle is used to isolate and block light; the microscope objective is used to focus light on the sample surface and observe the sample surface; the sample stage is used to carry the sample to be tested; the imaging camera is used to capture and record the image of the sample morphology under the microscope when the system realizes the microscopic imaging function; The spectrometer is used to disperse the composite light and separate the light of different wavelengths into different directions; the attenuation plate and polarizer are used to convert the laser output by the laser light source into laser of specific power and polarization angle; the dichroic mirror is used to filter the signal of the corresponding wavelength of the laser and its similar wavelength, and only transmit the effective light signal containing the sample information; the condenser is used to focus the incident light into a smaller area; the CCD detector is used to capture the light signals of different wavelengths, convert them into electronic signals and display them in the form of a spectrum.

4. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 3, characterized in that: The multifunctional microscopic spectrum test subsystem comprises an illumination light source (1), a first reflector (2), a first guide rail (3), a first transflector (4), a second reflector (5), a first optical baffle (6), a microscope objective (7), a sample stage (8), an imaging camera (9), a broadband adjustable light source (10), a first spectrometer (11), a second transflector (12), a second optical baffle (13), a second guide rail (14), a laser light source (15), an attenuation plate (16), a polarizer (17), a third optical baffle (18), a third guide rail (19), a dichroic mirror (20), a third reflector (21), a fourth reflector (22), a first condenser (23), a second condenser (24), a second spectrometer (25) and a CCD detector (26); Wherein, the first transmissive mirror (4) and the second reflective mirror (5) are fixed on the first guide rail (3); When it is necessary to observe the microscopic morphology of the sample, the first reflective mirror (4) and the second reflective mirror (5) are moved along the first guide rail (3) so that the first reflective mirror (4) is aligned with the microscope objective lens (7), and the illumination light emitted by the illumination light source (1) passes through the first reflective mirror (2) and the first reflective mirror (4) and then is emitted from the microscope objective lens (7). At this time, the second reflective mirror (5) and the first optical baffle (6) are not in operation; When collecting the spectrum, the optical path is adjusted to introduce the corresponding excitation light into the microscope objective lens (7) and shield the illumination light, and the first reflective mirror (4) and the second reflective mirror (5) are moved along the first guide rail (3) so that the second reflective mirror (5) is aligned with the microscope objective lens (7). At this time, the illumination light passes through the first reflective mirror (2) and the first reflective mirror (4) and is irradiated onto the first optical baffle (6).

5. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 4, characterized in that: The second transmissive reflector (12) is fixed on a second guide rail (14); When it is necessary to use broadband composite white light as an excitation light source, the second transflective mirror (12) is moved along the second guide rail (14) to align with the second reflective mirror (5). At this time, the composite white light emitted by the broadband adjustable light source (10) is reflected by the second transflective mirror (12) and the second reflective mirror (5) and then emitted by the microscope objective lens (7). At this time, the second optical baffle (13) does not work. When the composite white light is not needed as an excitation light source, the second transflective mirror (12) is moved along the second guide rail (14) to align with the second optical baffle (13), so that the composite white light is irradiated on the second optical baffle (13).

6. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 5, characterized in that: The dichroic mirror (20) is fixed on the third guide rail (19); When it is necessary to use laser as an excitation light source, the dichroic mirror (20) is moved along the third guide rail (19) to align with the second reflector (5). At this time, the laser light emitted by the laser light source (15) is reflected by the dichroic mirror (20) and the second reflector (5) and then emitted by the microscope objective lens (7). At this time, the third optical baffle (18) does not work; When the laser is not needed as an excitation light source, the dichroic mirror (20) is moved along the third guide rail (19) to align with the third optical baffle (18), so that the laser is irradiated on the third optical baffle (18).

7. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 6, characterized in that: The test environment control subsystem comprises a sample table (8), a cylinder gas (27), a vacuum pump (35), a cryogenic liquid bottle (36) and a gas pipeline (37); wherein the sample table (8) is a sealable chamber, and the cylinder gas (27), the cryogenic liquid bottle (36) and the vacuum pump (35) are all connected to the sample table (8).

8. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 7, characterized in that: Four metal probes for testing the photoelectric response of the sample are arranged in the chamber of the sample stage (8), a first vent (8.1) and a second vent (8.2) are arranged on both sides of the sample stage (8), and a light-permeable glass window (8.15) is arranged directly above.

9. The multifunctional microscopic spectrum testing system with adjustable test temperature and pressure according to claim 8, characterized in that: A pressure reducing valve (28), a stop valve (29), a pressure gauge (30) and a vacuum gauge (31) are provided on the gas pipeline connecting the cylinder gas (27) and the sample stage (8); the cryogenic liquid bottle (36) is directly connected to the sample stage (8); and the vacuum pump (35) is connected to the sample stage (8) via a ball valve (34).

10. Application of the multifunctional microscopic spectrum testing system with adjustable test temperature and pressure as claimed in any one of claims 1 to 9 in the field of spectrum detection technology.

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