An apparatus and method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials

Abstract

The application discloses a device and method for measuring fluorescence quantum yield of two-dimensional transition metal chalcogenide compound material, and belongs to the technical field of optical measurement and material characterization. The method comprises the following steps: calibrating a system response function about wavelength; measuring the absorption rate of the two-dimensional transition metal chalcogenide compound material to incident laser; measuring the photoluminescence spectrum of the two-dimensional transition metal chalcogenide compound material; measuring the integral intensity of the diffuse reflection spectrum under the same condition by using a diffuse reflection mirror; and calculating the fluorescence quantum yield of the two-dimensional transition metal chalcogenide compound material according to the system response function, the absorption rate of the two-dimensional transition metal chalcogenide compound material to incident laser, the photoluminescence spectrum of the two-dimensional transition metal chalcogenide compound material and the integral intensity of the diffuse reflection spectrum. The fluorescence quantum yield of the two-dimensional transition metal chalcogenide compound material can be accurately measured, so that the quantitative, rapid and non-destructive characterization of the light-emitting efficiency of the two-dimensional transition metal chalcogenide compound material is realized.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement and materials characterization technology, specifically relating to a device and method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials based on the Lambert diffuse reflection model. Background Technology

[0002] Photoluminescent quantum yield (PLQY), a key parameter characterizing the photoluminescence efficiency of materials, is defined as the ratio of the number of emitted fluorescent photons to the number of absorbed excitation photons per unit time. For two-dimensional transition-metal chalcogenides (TMDs) (such as...), PLQY is particularly important. For two-dimensional transition metal chalcogenides, their fluorescence quantum yield directly affects the performance limit of optoelectronic devices, such as photodetectors and light-emitting diodes. Therefore, accurate measurement of the fluorescence quantum yield of two-dimensional transition metal chalcogenides is of vital importance to the development of optoelectronic devices.

[0003] Currently, the mainstream measurement methods include the relative method (reference method) and the absolute method (integrating sphere method). Both methods face significant challenges when applied to the measurement of two-dimensional transition metal chalcogenides (TMCs). The relative method relies on a reference sample with a defined quantum yield. The quantum yield of the test sample is calculated by comparing the absorbance and fluorescence intensity of the reference sample and the test sample. However, the fluorescence emission peak positions of TMCs differ significantly from common reference materials (such as Rhodamine B and quinine sulfate), and their fluorescence intensity is affected by factors such as ambient humidity and substrate interface states, leading to difficulties in reference matching. Furthermore, the fluorescence intensity of monolayer TMCs is only on the order of one ten-thousandth of that of traditional fluorescent dyes, resulting in significant errors in photon counting statistics when using the integrating sphere method. Therefore, there is an urgent need to develop a measurement method that can accurately characterize the fluorescence quantum yield of two-dimensional TMC materials. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenides (TMDs) materials, in order to solve the problem that the weak fluorescence signal of monolayer or few-layer samples of two-dimensional transition metal chalcogenides leads to uncontrollable measurement errors and cannot accurately characterize their fluorescence quantum yield.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, an apparatus for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials is provided, comprising: The imaging optical path, along the direction of the incident optical path, includes, in sequence, an illumination source, a first beam splitter, an objective lens, and a three-axis adjustable displacement stage; along the direction of the reflected optical path, it includes, in sequence, a three-axis adjustable displacement stage, an objective lens, a first beam splitter, and a camera. The test optical path, along the incident optical path, includes, in sequence, a laser, a first tilting silver mirror, a second tilting silver mirror, a second beam splitter, an objective lens, and a three-axis adjustable displacement stage; along the reflected optical path, it includes, in sequence, a three-axis adjustable displacement stage, an objective lens, a second beam splitter, a third tilting silver mirror, a filter, a lens, and a spectrometer. A white light source is located on the other side of the second foldable silver mirror, and the light path direction is coaxial with the incident light path in the imaging light path; A computer used for testing and analysis, connected to a spectrometer.

[0006] Secondly, a method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials is provided, based on the aforementioned apparatus, comprising: Calibrate the system response function with respect to wavelength; Determine the absorption rate of incident laser light to two-dimensional transition metal chalcogenide materials; Determination of photoluminescence spectra of two-dimensional transition metal chalcogenide materials; The integrated intensity of the diffuse reflectance spectrum under the same conditions was measured using a diffuse reflectance mirror (Lambertian mirror); The fluorescence quantum yield of the two-dimensional transition metal chalcogenide material is calculated based on the system response function, the absorptivity of the two-dimensional transition metal chalcogenide material to the incident laser, the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material, and the integrated intensity of the diffuse reflectance spectrum of the diffuse reflector.

[0007] Furthermore, the calibration of the system response function with respect to wavelength includes: Turn on the lighting source and spectrometer; Place the silver mirror flat on the three-axis adjustable displacement stage; Adjust the Z-axis height of the three-axis adjustable displacement stage to focus the white light onto the surface of the silver mirror; Remove the lighting source and the first beam splitter; Turn on the white light source and flip the second flip-up silver mirror to let the white light pass through; White light spectra were collected using a spectrometer; Collect the factory-set spectral data of the white light source; The collected spectral data and the factory spectral data were normalized. The system response function is obtained by dividing the normalized acquired spectral data by the normalized factory spectral data.

[0008] Further, the determination of the absorption rate of the two-dimensional transition metal chalcogenide material to incident laser light includes: S21, turn on the lighting source, camera, and spectrometer; S22, place the two-dimensional transition metal chalcogenide material sample flat on a triaxial adjustable displacement stage; S23, adjust the Z-axis height of the three-axis adjustable displacement stage to make the sample clearly imaged on the camera surface; S24, remove the lighting source and the first beam splitter; S25, turn on the white light source and flip the second flip-up silver mirror to let the white light pass through; S26, Adjust the X and Y axes of the three-axis adjustable displacement stage so that the white light spot of the detector illuminates the target area of ​​the sample; S27, the transmission and reflection spectra of the sample are measured using a spectrometer; S28, replace the sample with a quartz substrate and a silver mirror, repeat the operations of S22-S27, and measure the transmission spectrum of the quartz substrate and the reflection spectrum of the silver mirror. S29. Using the measured transmission and reflection spectra of the sample, as well as the transmission spectrum of the quartz substrate and the reflection spectrum of the silver mirror, the absorption rate of the sample to the incident laser is calculated.

[0009] Furthermore, the absorption rate of the sample to the incident laser is calculated using the following formula: = 1 – / – / , in, The absorption rate of the two-dimensional transition metal chalcogenide material to the incident laser is denoted as . The reflectance spectrum of a two-dimensional transition metal chalcogenide material. The transmission spectrum of two-dimensional transition metal chalcogenide materials. The reflection spectrum of a silver mirror. The transmission spectrum is for a quartz substrate.

[0010] Furthermore, the determination of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material includes: S31, turn on the lighting source, camera, laser, and spectrometer; S32, place the two-dimensional transition metal chalcogenide material sample flat on a triaxial adjustable displacement stage; S33, adjust the Z-axis height of the three-axis adjustable displacement stage to make the sample clearly imaged on the camera surface; S34, remove the lighting source and the first beam splitter; S35, adjust the laser output power to the set value; S36, adjust the X and Y axes of the three-axis adjustable displacement stage so that the laser spot illuminates the target area of ​​the sample; S37, the photoluminescence spectrum of the sample is measured using a spectrometer.

[0011] Furthermore, the determination of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material further includes: S38. Adjust the output power of the laser and repeat step S37 to measure the variable power photoluminescence spectrum of the sample.

[0012] Furthermore, the method of measuring the integrated intensity of the diffuse reflectance spectrum under the same conditions using a diffuse reflector includes: S41, turn on the lighting source, camera, laser, and spectrometer; S42, place the diffuse mirror flat on the three-axis adjustable displacement stage; S43, adjust the Z-axis height of the three-axis adjustable displacement stage so that the diffuse mirror can clearly image the camera surface; S44, remove the lighting source and the first beam splitter; S45, adjust the laser output power to be the same as the excitation power for measuring the photoluminescence spectrum of two-dimensional transition metal chalcogenide materials; S46, adjust the X and Y axes of the three-axis adjustable displacement stage so that the laser spot illuminates the surface of the diffuse mirror; S47, Measure the diffuse reflectance spectrum of the diffuse reflector using a spectrometer; S48. Repeat steps S46 and S47 to illuminate different areas of the diffuse reflector surface with the laser spot. Measure the integrated intensity of the diffuse reflectance spectrum a preset number of times and take the average value as the integrated intensity of the diffuse reflectance spectrum.

[0013] In step S45, the laser power is measured by a power meter to adjust it to a set value, and a 1,000-fold attenuator is placed in the optical collection path.

[0014] Furthermore, the fluorescence quantum yield of the two-dimensional transition metal chalcogenide material is calculated according to the following formula: , in, The fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, The integral intensity of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material is given. Let be the reflectivity of the diffuse mirror surface. Let be the system response function with respect to wavelength. Let be the integrated intensity of the diffuse reflectance spectrum of the diffuse reflectance mirror surface. The absorption rate of the two-dimensional transition metal chalcogenide material to the incident laser is denoted as . The laser wavelength used to determine the integrated intensity of photoluminescence and diffuse reflectance spectra. For wavelength The value of the system response function corresponding to the laser.

[0015] The formula for the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials is obtained through the following steps: The formula for calculating fluorescence quantum yield is as follows: , in, The fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, The number of photons emitted by a two-dimensional transition metal chalcogenide material (i.e., the integrated intensity of the photoluminescence spectrum). The number of laser photons absorbed by the two-dimensional transition metal chalcogenide material.

[0016] In the formula and (that is, in the following formula) Experiments have confirmed that the spatial distribution of photoluminescence in two-dimensional transition metal chalcogenide materials can be approximated as Lambertian diffuse reflection. The specific expression is as follows: , , in, The intensity of the incident laser; The absorption rate of the two-dimensional transition metal chalcogenide material to incident laser light; The fluorescence quantum yield of two-dimensional transition metal chalcogenide materials; For wavelength The system response function represents the relationship between the relative sensitivity of the optical system and the wavelength; The integral intensity of the diffuse reflection spectrum of a continuous-wave laser focused on the surface of a diffuse mirror (Lambertian surface). It is the reflectivity of the Lambert surface ( ), The laser wavelength used to determine the integrated intensity of photoluminescence and diffuse reflectance spectra. For wavelength The value of the system response function corresponding to the laser.

[0017] From equations (2) and (3), we can derive: , The fluorescence quantum yield of the final two-dimensional transition metal chalcogenide material was derived. : .

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes the near-Lambertian diffuse reflectance properties of photoluminescence signals from transition metal chalcogenides (TMCs). By designing a specific optical system, the fluorescence quantum yield of two-dimensional TMCs can be accurately measured, thus achieving quantitative, rapid, and non-destructive characterization of their luminescence efficiency. This method avoids the dependence on standard samples in traditional reference methods, significantly improving the measurement sensitivity and reliability of weakly luminescent materials. The method is simple to operate, with a highly modular optical path and controllable cost, making it easy to integrate into existing spectral characterization platforms. It can be widely used in the research and development of optoelectronic materials and devices, providing crucial technical support for the development of novel optoelectronic technologies. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the optical path structure of the device for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to an embodiment of the present invention; Figure 2 It is a single-layer tungsten sulfide (TSF) according to an embodiment of the present invention. The variable power photoluminescence spectrum of ) Figure 3 This is an embodiment of the invention for measuring monolayer tungsten sulfide ( The results of fluorescence quantum yield are shown in the figure.

[0020] In the figure, 1-Illumination source, 2-First beam splitter, 3-Objective lens, 4-Triaxial adjustable stage, 5-Camera, 6-Laser, 7-First tilting silver mirror, 8-Second tilting silver mirror, 9-Second beam splitter, 10-Third tilting silver mirror, 11-Filter, 12-Lens, 13-Spectrometer, 14-Computer, 15-White light source. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. These embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0022] Example 1

[0023] like Figure 1 As shown, an embodiment of the present invention provides an apparatus for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, comprising: The imaging optical path, along the direction of the incident optical path, includes, in sequence: an illumination source 1, a first beam splitter 2, an objective lens 3, and a triaxially adjustable displacement stage 4 for carrying the sample; along the direction of the reflected optical path, it includes, in sequence: a triaxially adjustable displacement stage 4, an objective lens 3, a first beam splitter 2, and a camera 5.

[0024] The test optical path, along the incident light path direction, includes, in sequence: a laser 6, a first tilting silver mirror 7, a second tilting silver mirror 8, a second beam splitter 9, an objective lens 3, and a three-axis adjustable displacement stage 4; along the reflected light path direction (or collection light path), it includes, in sequence: a three-axis adjustable displacement stage 4, an objective lens 3, a second beam splitter 9, a third tilting silver mirror 10, a filter 11, a lens 12, and a spectrometer 13, used to collect and transmit the spectral signal emitted by the sample to the spectrometer 13.

[0025] The white light source 15 is located on the other side of the second foldable silver mirror 8, and its light path direction is coaxial with the incident light path in the imaging light path.

[0026] The computer 14, used for testing and analysis, is connected to the spectrometer 13.

[0027] The camera can be a CCD camera or a CMOS camera.

[0028] In the device described, the white light reflected from the sample passes through the objective lens 3 and the first beam splitter 2 in the imaging optical path, ultimately forming a clear image on the surface of the camera 5. During spectral acquisition, the illumination source 1 and the first beam splitter 2 in the imaging optical path must be removed. The test optical path can be divided into an incident optical path and a collecting optical path. The incident optical path originates from the laser 6, and the emitted beam passes sequentially through the first tilting silver mirror 7, the second tilting silver mirror 8, the second beam splitter 9, and the objective lens 3 before being perpendicularly incident on the sample placed on the surface of the triaxial adjustable displacement stage 4. The collecting optical path receives the beam reflected from the sample, allowing it to pass sequentially through the objective lens 3, the second beam splitter 9, the third tilting silver mirror 10, the filter 11, and the lens 12, and finally enters the spectrometer 13 to acquire the reflection spectrum. The acquired data is processed and analyzed by a computer system.

[0029] When testing the sample, the illumination source 1 and the first beam splitter 2 in the imaging optical path need to be removed, and a white light source 15 needs to be introduced to measure the absorptivity and reflectivity of the sample.

[0030] If variable power fluorescence quantum yield measurement is required, the output power of laser 6 can be adjusted and the spectral acquisition process can be repeated to obtain the spectral response of the sample under different excitation powers, thereby obtaining the power-dependent spectral characteristics of the sample.

[0031] Example 2

[0032] This embodiment uses a single layer of tungsten sulfide ( Taking tungsten sulfide as an example, a method for measuring monolayer tungsten sulfide (TSD) Methods for fluorescence quantum yield include: Step 1, calibrate the system response function with respect to wavelength. ; This step specifically includes: S11, turn on the illumination source 1 and the spectrometer 13; S12, place the silver mirror flat on the three-axis adjustable displacement stage 4; S13, adjust the Z-axis height of the three-axis adjustable displacement stage 4 so that the white light is focused on the surface of the silver mirror; S14, remove the lighting source 1 and the first beam splitter 2; S15, turn on the white light source 15 and flip the second flip-up silver mirror 8 to allow the white light to pass through; S16, white light spectrum is acquired by spectrometer 13; S17, collect the factory spectral data of white light source 15; S18, normalize the collected spectral data and the factory spectral data; S19, divide the normalized acquired spectral data by the normalized factory spectral data to obtain the system response function. .

[0033] Step 2, determine the monolayer tungsten sulfide ( Absorption rate of the sample material to the incident laser ; This step specifically includes: S21, turn on the lighting source 1, camera 5 and spectrometer 13; S22, a single layer of tungsten sulfide ( The sample is placed flat on the triaxial adjustable displacement stage 4; S23, adjust the Z-axis height of the three-axis adjustable displacement stage 4 so that the sample is clearly imaged on the surface of the camera 5; S24, remove the lighting source 1 and the first beam splitter (2); S25, turn on the white light source 15 and flip the second flip-up silver mirror 8 to allow the white light to pass through; S26, adjust the X and Y axes of the three-axis adjustable displacement stage 4 so that the white light spot of the detector illuminates the target area of ​​the sample; S27, Measurement of monolayer tungsten sulfide (S27) was performed using spectrometer 13. Transmission spectrum of the sample and reflection spectrum ; S28, replace the sample with a quartz substrate and a silver mirror, repeat steps S22-S27, and measure the transmission spectrum of the quartz substrate. and the reflection spectrum of a silver mirror ; S29, using the measured monolayer tungsten sulfide ( Transmission spectrum of the sample and reflection spectrum and the transmission spectrum of the quartz substrate and the reflection spectrum of a silver mirror Calculate the absorption rate of the sample to the incident laser. .

[0034] Single-layer tungsten sulfide ( The absorption rate of the sample to the incident laser is calculated using the following formula: = 1 – / – , in, Single-layer tungsten sulfide ( The absorption rate of the sample to the incident laser. Single-layer tungsten sulfide ( The reflectance spectrum of the sample, Single-layer tungsten sulfide ( The transmission spectrum of the sample, The reflection spectrum of a silver mirror. The transmission spectrum is for a quartz substrate.

[0035] Step 3, determine the monolayer tungsten sulfide ( Photoluminescence spectrum of sample material ; This step specifically includes: S31, turn on the lighting source 1, camera 5, laser 6 and spectrometer 13; S32, a single layer of tungsten sulfide ( The sample is placed flat on the triaxial adjustable displacement stage 4; S33, adjust the Z-axis height of the three-axis adjustable displacement stage 4 so that the sample is clearly imaged on the surface of the camera 5; S34, remove the lighting source 1 and the first beam splitter (2); S35, adjust the output power of laser 6 to (Measured by a power meter), and a 1,000x attenuator is placed in the optical collection path; S36, adjust the X and Y axes of the three-axis adjustable displacement stage 4 so that the laser spot illuminates the target area of ​​the sample; S37, the photoluminescence spectrum of the sample is measured by spectrometer 13.

[0036] S38. If variable power fluorescence quantum yield measurement is required, adjust the output power of laser 6 and repeat step S37 to measure the photoluminescence spectrum of the sample at different laser powers.

[0037] With wavelength as the independent variable and light intensity as the dependent variable, different colors represent different output powers of the laser, and a monolayer of tungsten sulfide ( Variable power photoluminescence spectrum of the sample The spectrum, the results are as follows Figure 2As shown.

[0038] Step 4: Measure the integrated intensity of the diffuse reflectance spectrum under the same conditions using a diffuse reflector (Lambertian mirror). ; This step specifically includes: S41, turn on the lighting source 1, camera 5, laser 6 and spectrometer 13; S42, place the diffuse mirror flat on the three-axis adjustable displacement stage 4; S43, adjust the Z-axis height of the three-axis adjustable displacement stage 4 so that the diffuse mirror can clearly image the surface of the camera 5. S44, remove the illumination source 1 and the first beam splitter 2; S45, adjust the laser output power to And a 1,000-fold attenuation plate is placed in the optical collection path; S46, adjust the X and Y axes of the three-axis adjustable displacement stage 4 so that the laser spot illuminates the surface of the diffuse mirror; S47, the diffuse reflectance spectrum of the laser from the diffuse reflector is measured using spectrometer 13; S48. Repeat steps S46 and S47 to illuminate different areas of the diffuse reflector surface with the laser spot. The integrated intensity of the diffuse reflectance spectrum needs to be measured one hundred times. Remove the five maximum and five minimum values, and then take the average value as the integrated intensity of the diffuse reflectance spectrum. .

[0039] In this embodiment, the laser used in steps 3 and 4 is a 532nm laser. It is the integrated intensity of the diffuse reflection spectrum of a continuous-wave laser (532nm) focused on a Lambertian surface.

[0040] Step 5, based on the system response function Single-layer tungsten sulfide ( The sample's absorption rate of the incident laser. Single-layer tungsten sulfide ( Photoluminescence spectrum of the sample And the integrated intensity of the diffuse reflectance spectrum of the diffuse reflector Calculate the single-layer tungsten sulfide ( Fluorescence quantum yield of materials ; Calculate monolayer tungsten sulfide ( Fluorescence quantum yield of materials The corresponding formula is as follows: , in, , They are single-layer tungsten sulfide ( The number of photons emitted by the material (i.e., the integrated intensity of the photoluminescence spectrum) and the number of laser photons absorbed.

[0041] In the formula and (that is, in the following formula) This is because of the single layer of tungsten sulfide ( The spatial distribution of photoluminescence can be approximated as Lambertian diffuse reflection. The specific expression is: , , in, The intensity of the incident laser. Single-layer tungsten sulfide ( The absorption rate of the material to the incident laser. Single-layer tungsten sulfide ( The fluorescence quantum yield of the material, For wavelength The system response function, The integrated intensity of the diffuse reflection spectrum of a continuous-wave laser (532 nm) focused on a Lambertian surface. It is the reflectivity of the Lambert surface ( ), This is the value of the system response function corresponding to a laser with a wavelength of 532nm, because a laser with a wavelength of 532nm is used.

[0042] From equations (2) and (3), we can derive: , The final monolayer tungsten sulfide (TSF) was derived. fluorescence quantum yield : .

[0043] According to equation (5), with the exciton generation rate as the independent variable, monolayer tungsten sulfide ( fluorescence quantum yield Plotting the dependent variable yields the following distribution graph: Figure 3 As shown in the diagram. Based on this distribution, the monolayer tungsten sulfide (tungsten sulfide) can be obtained at different exciton generation rates. fluorescence quantum yield .

[0044] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. All technical solutions obtained by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the present invention.

Claims

1. An apparatus for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, characterized in that, include: The imaging optical path includes, in sequence along the incident optical path direction, an illumination source (1), a first beam splitter (2), an objective lens (3), and a three-axis adjustable displacement stage (4); and in sequence along the reflected optical path direction, a three-axis adjustable displacement stage (4), an objective lens (3), a first beam splitter (2), and a camera (5). The test optical path includes, in sequence along the incident optical path, a laser (6), a first tiltable silver mirror (7), a second tiltable silver mirror (8), a second beam splitter (9), an objective lens (3), and a three-axis adjustable displacement stage (4); and in sequence along the reflected optical path, a three-axis adjustable displacement stage (4), an objective lens (3), a second beam splitter (9), a third tiltable silver mirror (10), a filter (11), a lens (12), and a spectrometer (13). A white light source (15) is set on the other side of the second foldable silver mirror (8), and the light path direction is coaxial with the incident light path in the imaging light path; A computer (14) for testing and analysis is connected to a spectrometer (13).

2. A method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, characterized in that, Based on the device described in claim 1, it includes: Calibrate the system response function with respect to wavelength; Determine the absorption rate of incident laser light to two-dimensional transition metal chalcogenide materials; Determination of photoluminescence spectra of two-dimensional transition metal chalcogenide materials; The integrated intensity of the diffuse reflectance spectrum under the same conditions was measured using a diffuse reflectance mirror; The fluorescence quantum yield of the two-dimensional transition metal chalcogenide material is calculated based on the system response function, the absorptivity of the two-dimensional transition metal chalcogenide material to the incident laser, the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material, and the integrated intensity of the diffuse reflectance spectrum of the diffuse reflector.

3. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 2, characterized in that, The calibration of the system response function with respect to wavelength includes: Turn on the lighting source (1) and the spectrometer (13); Place the silver mirror flat on the three-axis adjustable displacement stage (4); Adjust the Z-axis height of the three-axis adjustable displacement stage (4) to focus the white light onto the surface of the silver mirror; Remove the lighting source (1) and the first beam splitter (2); Turn on the white light source (15) and flip the second flip-up silver mirror (8) to allow the white light to pass through; White light spectra were collected using a spectrometer (13); Collect the factory spectral data of the white light source (15); The collected spectral data and the factory spectral data were normalized. The system response function is obtained by dividing the normalized acquired spectral data by the normalized factory spectral data.

4. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 2, characterized in that, The determination of the absorption rate of the two-dimensional transition metal chalcogenide material to incident laser light includes: S21, turn on the lighting source (1), camera (5) and spectrometer (13); S22, place the two-dimensional transition metal chalcogenide material sample flat on the triaxial adjustable displacement stage (4); S23, adjust the Z-axis height of the three-axis adjustable displacement stage (4) so ​​that the sample is clearly imaged on the surface of the camera (5); S24, remove the lighting source (1) and the first beam splitter (2); S25, turn on the white light source (15) and flip the second flip-up silver mirror (8) to allow the white light to pass through; S26, adjust the X-axis and Y-axis of the three-axis adjustable displacement stage (4) so ​​that the white light spot of the detector illuminates the target area of ​​the sample; S27, the transmission and reflection spectra of the sample are measured by a spectrometer (13); S28, replace the sample with a quartz substrate and a silver mirror, repeat the operations of S22-S27, and measure the transmission spectrum of the quartz substrate and the reflection spectrum of the silver mirror. S29. Using the measured transmission and reflection spectra of the sample, as well as the transmission spectrum of the quartz substrate and the reflection spectrum of the silver mirror, the absorption rate of the sample to the incident laser is calculated.

5. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 4, characterized in that, The absorption rate of the sample to the incident laser is calculated using the following formula: = 1 – / – / ， in, The absorption rate of the two-dimensional transition metal chalcogenide material to the incident laser is denoted as . The reflectance spectrum of a two-dimensional transition metal chalcogenide material. The transmission spectrum of two-dimensional transition metal chalcogenide materials. The reflection spectrum of a silver mirror. The transmission spectrum is for a quartz substrate.

6. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 2, characterized in that, The determination of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material includes: S31, turn on the lighting source (1), camera (5), laser (6) and spectrometer (13); S32, place the two-dimensional transition metal chalcogenide material sample flat on the triaxial adjustable displacement stage (4); S33, adjust the Z-axis height of the three-axis adjustable displacement stage (4) so ​​that the sample is clearly imaged on the surface of the camera (5); S34, remove the lighting source (1) and the first beam splitter (2); S35, adjust the output power of the laser (6) to the set value; S36, adjust the X and Y axes of the three-axis adjustable displacement stage (4) so ​​that the laser spot irradiates the target area of ​​the sample; S37, the photoluminescence spectrum of the sample is measured by a spectrometer (13).

7. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 6, characterized in that, The determination of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material further includes: S38, adjust the output power of the laser (6), repeat step S37, and measure the variable power photoluminescence spectrum of the sample.

8. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 2, characterized in that, The method of measuring the integrated intensity of diffuse reflectance spectra under the same conditions using a diffuse reflector includes: S41, turn on the lighting source (1), camera (5), laser (6) and spectrometer (13). S42, place the diffuse mirror flat on the three-axis adjustable displacement stage (4); S43, adjust the Z-axis height of the three-axis adjustable displacement stage (4) so ​​that the diffuse mirror can clearly image the surface of the camera (5); S44, remove the lighting source (1) and the first beam splitter (2); S45, adjust the output power of the laser (6) to be the same as the excitation power for measuring the photoluminescence spectrum of two-dimensional transition metal chalcogenide materials; S46, adjust the X and Y axes of the three-axis adjustable displacement stage (4) so ​​that the laser spot illuminates the surface of the diffuse mirror; S47, the diffuse reflectance spectrum of the diffuse reflector is measured by a spectrometer (13); S48. Repeat steps S46 and S47 to illuminate different areas of the diffuse reflector surface with the laser spot. Measure the integrated intensity of the diffuse reflectance spectrum a preset number of times and take the average value as the integrated intensity of the diffuse reflectance spectrum.

9. The method for measuring the fluorescence quantum yield of two-dimensional transition metal chalcogenide materials according to claim 2, characterized in that, The fluorescence quantum yield of the two-dimensional transition metal chalcogenide material is calculated according to the following formula: ， in, The fluorescence quantum yield of two-dimensional transition metal chalcogenide materials, The integral intensity of the photoluminescence spectrum of the two-dimensional transition metal chalcogenide material is given. Let be the reflectivity of the diffuse mirror surface. Let be the system response function with respect to wavelength. Let be the integrated intensity of the diffuse reflectance spectrum of the diffuse reflectance mirror surface. The absorption rate of the two-dimensional transition metal chalcogenide material to the incident laser is denoted as . The laser wavelength used to determine the integrated intensity of photoluminescence and diffuse reflectance spectra. For wavelength The value of the system response function corresponding to the laser.

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