Method and device for detecting friction-induced defect based on interlayer exciton lifetime of two-dimensional material

Abstract

The invention provides a method and device for detecting friction-induced defects based on two-dimensional material interlayer exciton lifetime, and relates to the technical field of tribology. The method comprises the following steps: scanning the surface of a target object by using pulse laser; obtaining an interlayer exciton signal generated by exciting each region in a plurality of regions on the surface of the target object; determining a photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited by each region, and comparing the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; under the condition that the comparison result indicates that the photoluminescence decay rate corresponding to any target area is smaller than the standard rate, determining that the target area has friction defects; wherein the friction force on the surface of the target object is in positive correlation with the photoluminescence decay rate. According to the method provided by the invention, high-precision detection of friction-induced defects is realized.

Description

Technical Field

[0001] The present invention relates to the field of tribology technology, and in particular to a method and device for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers. Background Art

[0002] Friction is one of the most common physical phenomena in life. More than one-third of energy is lost in industrial production due to friction, and 80% of mechanical moving parts fail due to wear and tear. In particular, for low-dimensional electronic devices, such as micro-nano electromechanical systems, due to their high specific surface area, friction and wear on the surface will seriously affect the performance of the device. Therefore, reducing friction is of great significance for optimizing material performance and developing new functions.

[0003] Two-dimensional material heterojunctions are considered to be an ideal platform for achieving extremely low friction due to the weak interlayer van der Waals forces. However, defects are inevitable at the frictional motion interface of two-dimensional materials. Studies have found that defects increase the dissipation of interfacial friction energy and significantly reduce the stability of equipment and devices. However, the accurate identification and detection of atomic-level defects at the friction interface is still a major problem. The difficulty lies mainly in the fact that the atomic-scale dynamic process caused by defects occurs on the fs~ps time scale, the signal dissipates quickly, and the detection is extremely difficult. The existing atomic force microscope has a slow detection speed, and the detection accuracy is affected by multiple factors such as the probe size, so it is impossible to accurately identify atomic-level defects. The scanning transmission electron microscope sample preparation process is cumbersome and the detection efficiency is low. Raman spectroscopy and PL spectroscopy detection methods can only achieve steady-state detection, and cannot achieve detection of dynamic processes.

[0004] How to achieve high-precision detection of friction-induced defects at ultra-high temporal and spatial scales is a technical problem that needs to be solved at present. Summary of the invention

[0005] The present invention provides a method and device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, so as to solve the defects existing in the prior art.

[0006] The present invention provides a method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, comprising the following steps: Scanning the surface of the target object using a pulsed laser, and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, it is determined that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0007] According to a method for detecting friction-induced defects based on the lifetime of interlayer excitons in two-dimensional materials provided by the present invention, a pulsed laser is used to scan the surface of a target object, and an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object is obtained, comprising: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

[0008] According to a method for detecting friction-induced defects based on the interlayer exciton lifetime of a two-dimensional material provided by the present invention, the photoluminescence decay rate corresponding to each region is determined based on the interlayer exciton signal excited in each region, comprising: A time-resolved photoluminescence decay curve corresponding to each region is fitted based on the interlayer exciton signal excited in each region, and a photoluminescence decay rate corresponding to each region is calculated based on the time-resolved photoluminescence decay curve.

[0009] According to a method for detecting friction-induced defects based on the interlayer exciton lifetime of a two-dimensional material provided by the present invention, the time-resolved photoluminescence decay curve corresponding to each region is fitted based on the interlayer exciton signal excited in each region, comprising: Performing convolution processing on the interlayer exciton signal excited in each region to obtain a processed interlayer exciton signal, and fitting the processed interlayer exciton signal using a single exponential decay function to obtain the time-resolved photoluminescence decay curve; The convolution process is used to influence the instrument response function.

[0010] According to a method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers provided by the present invention, the standard rate is calibrated based on the following steps: A load of a first preset pressure value is applied to the surface of the two-dimensional material to be calibrated, and the load applied to the surface of the two-dimensional material to be calibrated is gradually reduced to a second preset pressure value, and calibration is performed using a wedge grating method to obtain the standard rate.

[0011] The present invention also provides a device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, comprising the following modules: An acquisition module, used to scan the surface of the target object using a pulsed laser, and acquire an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; A comparison module, used to determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and to compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; A determination module is used to determine that a friction defect exists in any target area when the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0012] According to a device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers provided by the present invention, the acquisition module is specifically used for: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements any of the above-described methods for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers.

[0015] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers.

[0016] The present invention provides a method and device for detecting friction-induced defects based on the interlayer exciton lifetime of a two-dimensional material, wherein the surface of a target object is scanned by using a pulsed laser, and an interlayer exciton signal generated by the excitation of each region in multiple regions on the surface of the target object is obtained; the photoluminescence decay rate corresponding to each region is determined based on the interlayer exciton signal excited in each region, and the photoluminescence decay rate corresponding to each region is compared with a pre-calibrated standard rate to generate a comparison result; when the comparison result indicates that the photoluminescence decay rate corresponding to any target region is less than the standard rate, it is determined that the target region has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate. It can be seen that the present invention detects the change of the exciton lifetime during the friction process by time-resolved photoluminescence spectroscopy to achieve high-precision detection of friction-induced defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a schematic flow chart of a method for detecting friction-induced defects based on the lifetime of interlayer excitons of two-dimensional materials provided by the present invention.

[0019] Figure 2 This is an image of MoS2 / WS2 / hBN provided by the present invention under an optical microscope.

[0020] Figure 3 It is the Raman spectrum of the single-layer WS2, single-layer MoS2 and MoS2 / WS2 heterojunction region provided by the present invention.

[0021] Figure 4 It is the photoluminescence spectrum of the single-layer WS2, single-layer MoS2 and MoS2 / WS2 heterojunction region provided by the present invention.

[0022] Figure 5 It is a photoluminescence spectrum diagram of the interlayer excitons provided by the present invention.

[0023] Figure 6 It is a schematic diagram of the friction process and detection of the interlayer exciton lifetime provided by the present invention.

[0024] Figure 7 These are the morphological images of the original and friction samples provided by the present invention.

[0025] Figure 8It is the friction force diagram of the original and after friction provided by the present invention.

[0026] Fig. 9 It is the photoluminescence spectrum diagram of the original and frictioned interlayer excitons provided by the present invention.

[0027] Fig.10 It is a schematic diagram of the quenching of the interlayer exciton photoluminescence intensity after friction provided by the present invention.

[0028] Fig.11 These are the Raman spectra of the original and friction-treated MoS2 regions and the fitting results of the corresponding characteristic peaks provided by the present invention.

[0029] Fig.12 The present invention provides lifetime decay diagrams of original and frictioned interlayer excitons and lifetime results after single exponential fitting.

[0030] Fig.13 The exciton dynamics of pristine and defective samples provided by the present invention.

[0031] Fig.14 The present invention provides a graph showing the change of the original and post-friction friction forces with the load, as well as the relationship between the life span and the friction coefficient.

[0032] Fig.15 It is a schematic diagram of the structure of a device for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers provided by the present invention.

[0033] Fig.16 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Combine the following Figure 1-Figure 16 The present invention describes a method and device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers.

[0036] Figure 1 : is a schematic flow chart of a method for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 100: Use a pulsed laser to scan the surface of a target object, and obtain an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object.

[0037] It should be noted that the existing atomic force microscope has a slow detection speed, and the detection accuracy is affected by multiple factors such as the probe size, and it is impossible to accurately identify atomic-level defects. The scanning transmission electron microscope sample preparation process is cumbersome and the detection efficiency is low. Raman spectroscopy and PL spectroscopy detection methods can only achieve steady-state detection, and cannot achieve the detection of dynamic processes. Based on this, an embodiment of the present invention provides a method for detecting friction-induced defects based on the lifetime of interlayer excitons of two-dimensional materials to solve at least one of the above problems.

[0038] Figure 2 This is the image of MoS2 / WS2 / hBN provided by the present invention under an optical microscope. Figure 2 Optical images of MoS2 / WS2 / hBN heterojunctions are shown. Monolayer MoS2 and monolayer WS2 are mechanically exfoliated from bulk crystals, and then MoS2 / WS2 / hBN heterojunctions are prepared using a layer-by-layer dry transfer method. hBN can serve as a flat substrate for the heterojunction, while also shielding Si / SiO2 defects and improving sample quality. The top layer of MoS2 is not encapsulated with hBN in order to introduce defects on its surface. After the friction defects are prepared, the top layer of MoS2 is encapsulated with hBN for subsequent spectral testing. The interlayer twist angle of the heterojunction is controlled by second harmonic generation and a precision translation stage. Figure 3 The Raman spectra of the monolayer WS2, monolayer MoS2 and MoS2 / WS2 heterojunction regions provided by the present invention are shown in Figure 1. The SHG signals of the monolayer MoS2, WS2 and MoS2 / WS2 heterojunction are shown in Figure 2. Figure 3 shown.

[0039] The strong interlayer coupling of the pure heterojunction can be confirmed by PL spectroscopy and Raman spectroscopy. Figure 4 is the photoluminescence spectrum of the single-layer WS2, single-layer MoS2 and MoS2 / WS2 heterojunction region provided by the present invention, and X A represents the in-plane A excitons of the two materials, and IX represents the interlayer excitons, such as Figure 4 As shown, in this embodiment, the -1 and ~417cm -1 , and ~384 cm -1 and ~402 cm -1 The in-plane E of WS2 and MoS2 was observed 1 2g and outer surface A 1g In the heterojunction region, this example found that the A 1gThe peaks are significantly enhanced, indicating that the heterojunction has strong interlayer coupling. The PL spectrum image shows that the fluorescence emission peaks of monolayer MoS2 and monolayer WS2 are 1.85eV and 2.01eV, respectively. Figure 5 : is the photoluminescence spectrum of the interlayer exciton provided by the present invention. In the heterojunction region, the A exciton PL peak of MoS2 is significantly quenched and red-shifted, and a new peak is generated near 1.5 eV. This embodiment attributes it to the interlayer exciton peak, marked as IX, as shown in Figure 5 shown.

[0040] In this embodiment, a reciprocating friction experiment is first performed on the heterojunction surface. Figure 6 Schematic diagram of the friction process and detection of interlayer exciton lifetime provided by the present invention, such as Figure 6 As shown. The atomic force microscope used was NT-MDT NTEGRA. A harder probe (NSG30, k = 32 N / m) was used, and the selected sample area was reciprocated and scanned in contact mode. Here, the applied loads were 1000nN, 1500nN, and 2000nN. The number of scans for each area was set to 50. After the scan was completed, a softer probe (CONTPt-10, Nanoworld, k=0.2 Nm -1 ), characterize the morphology and friction of different regions, Figure 7 This is the morphology of the original and friction samples provided by the present invention. Figure 8 The friction diagrams of the original and friction-treated surfaces provided by the present invention are as follows: Figure 7 and Figure 8 The results show that after reciprocating friction, the atomic force morphology does not show obvious differences, but there are significant differences in the friction forces in different areas. A reasonable inference is that after the friction test, atomic-level defects that cannot be distinguished by atomic force morphology are generated in the sample.

[0041] To verify the hypothesis of defect generation, spectral tests were carried out on the friction areas under different loads. Fig. 9 The photoluminescence spectra of the original and friction interlayer excitons provided by the present invention are as follows: Fig. 9 The photoluminescence spectra of interlayer excitons of samples in different regions are shown. With the increase of friction load, the interlayer exciton peak is gradually quenched, which is similar to the PL change trend caused by the actual defect generation. This similarity can preliminarily prove the existence of defects and implies that the defect concentration gradually increases with the increase of friction load. This embodiment attributes the cause of the quenching of the interlayer exciton peak to the capture of electrons by defect energy levels. When defects are introduced into the surface through AFM probe friction, defect energy levels will be generated in the bandgap of the material. The defect energy levels will capture electrons in the conduction band, thereby inhibiting the radiative recombination process of electrons and holes, resulting in the quenching of the photoluminescence intensity of the interlayer excitons. Fig.10 is a schematic diagram of the quenching of the interlayer exciton photoluminescence intensity after friction provided by the present invention, where hv represents luminescence, as shown in FIG. Fig.10 shown.

[0042] To further prove the existence of defects in the sample, Raman spectroscopy tests were performed. Fig.11 The Raman spectra of the original and friction MoS2 regions provided by the present invention and the fitting results of the corresponding characteristic peaks are shown in FIG. Fig.11 As shown. Four main peaks can be observed in the original MoS2 / WS2 heterojunction, among which 384cm -1 and 402cm -1 The peak is assigned to the E 2g 1 and A 1g Modal, 356cm -1 and 417cm -1 The peak is assigned to the E of WS2 2g 1 and A 1g Mode. E of MoS2 after atomic force probe rubbing 2g 1 The peak is red-shifted, A 1g The peak is blue-shifted, which is consistent with the results of MoS2 after plasma bombardment. This shows that the defect concentration gradually increases with the increase of friction load.

[0043] Although FFM, PL and Raman spectroscopy can identify atomic-level defects, they cannot detect defect-related dynamic behaviors that occur on ultrafast time scales. Here, this embodiment uses the long lifetime characteristics of interlayer excitons and uses time-resolved photoluminescence spectroscopy to track the exciton energy dissipation dynamics under different defect concentrations.

[0044] Based on the above embodiment, in this embodiment, step 100 uses a pulsed laser to scan the surface of the target object, and obtains an interlayer exciton signal generated by each of multiple regions on the surface of the target object being excited, including: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

[0045] Specifically, using pulsed laser ( ) for excitation. All signals were collected through a bandpass filter (ET785 / 60, Chroma) to filter out the A exciton signals of WS2 and MoS2 and retain only the signals of interlayer excitons.

[0046] Optionally, the disulfide described in this embodiment includes: disulfide WS2 and molybdenum disulfide MoS2.

[0047] Step 200: Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result.

[0048] It should be noted that photoluminescence (PL) decay refers to the process of the luminescence intensity of a material changing over time after light excitation. Specifically, when a material absorbs photons, electrons are excited to a higher energy level, and then return to the ground state through radiation or non-radiation processes, releasing photons. In this process, the luminescence intensity gradually weakens over time, which is PL decay.

[0049] Based on the above embodiment, in this embodiment, determining the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region in step 200 includes: A time-resolved photoluminescence decay curve corresponding to each region is fitted based on the interlayer exciton signal excited in each region, and a photoluminescence decay rate corresponding to each region is calculated based on the time-resolved photoluminescence decay curve.

[0050] Based on the above embodiment, in this embodiment, fitting the time-resolved photoluminescence decay curve corresponding to each region based on the interlayer exciton signal excited in each region includes: Performing convolution processing on the interlayer exciton signal excited in each region to obtain a processed interlayer exciton signal, and fitting the processed interlayer exciton signal using a single exponential decay function to obtain the time-resolved photoluminescence decay curve; The convolution process is used to influence the instrument response function (IRF).

[0051] Specifically, Fig.12It is the lifetime decay diagram of the original and frictioned interlayer excitons provided by the present invention and the lifetime result after single exponential fitting. The TRPL decay curves of different scanning areas and their corresponding fitting curves are shown in Figure 12. The gray area is the IRF of the system. Before fitting, all data need to be deconvolved to eliminate the influence of IRF. The deconvolved curve can be well fitted by the single exponential decay function. For the original MoS2 / WS2 heterojunction, the lifetime of the interlayer exciton is about 5.5ns. This time scale is much longer than the time scale of the intralayer exciton (tens to hundreds of ps). After scanning, the PL decay rate becomes faster and the interlayer lifetime becomes shorter, as short as 4.2 ns, which is nearly 25% longer than the original. The mechanism of the shortening of the interlayer exciton lifetime can be understood as follows. The original MoS2 / WS2 heterojunction is a type II band structure, and its conduction band bottom and valence band top are located in the MoS2 layer and WS2 layer, respectively, so that electrons and holes tend to transfer to energy levels with better energy to form interlayer excitons, Fig.13 is the exciton dynamics process of the original and defective samples provided by the present invention, wherein ① represents the electron being excited, ② represents the electron being scattered by the phonon, ③ represents the interlayer exciton recombination, ④ represents the interlayer charge transfer, and ⑤ represents the defect state capture, as shown in detail. Fig.13 As shown in the left half. Since the electron-hole wave function overlap is reduced, the lifetime is longer. When the atomic force probe is rubbed on the sample surface, the sample will be damaged and defects will be generated, and defect states will be introduced into the MoS2 layer ( Fig.13 The defect state will capture the electrons in the interlayer excitons accumulated in the MoS2 layer, which is equivalent to introducing an additional energy dissipation channel, causing a significant decrease in the interlayer exciton population, thereby reducing the interlayer exciton lifetime.

[0052] Step 300: When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, determine that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0053] It should be noted that the standard rate is calibrated based on the following steps: A load of a first preset pressure value is applied to the surface of the two-dimensional material to be calibrated, and the load applied to the surface of the two-dimensional material to be calibrated is gradually reduced to a second preset pressure value, and calibration is performed using a wedge grating method to obtain the standard rate.

[0054] Specifically, the high sensitivity of the interlayer exciton lifetime to defects makes it a useful probe for detecting defect-related behaviors, such as defect-induced changes in the coefficient of friction. Fig.14 The present invention provides a graph showing the change of the original and post-friction friction force with the load, as well as the relationship between the life span and the friction coefficient. Fig.14The left half shows the friction data under different loads in different regions. The friction is calibrated using the wedge grating method. The load is first preset to 50 nN and then gradually reduced to 5 nN. It can be seen that the friction in all regions increases linearly with the load, and with the increase in defect concentration, the friction force gradually increases, and the friction coefficient also gradually increases. This law is similar to the law that the interlayer exciton lifetime changes with the defect concentration. Fig.14 The right half plots the coefficient of friction as a function of the lifetime of the interlayer exciton. It can be seen that there is a strong correlation between the two. When the lifetime of the interlayer exciton becomes shorter, the coefficient of friction increases accordingly, and there is a one-to-one correspondence between the two. Therefore, the lifetime of the interlayer exciton can be used to predict the change in friction caused by defects, which is a powerful means to detect defects and their related behaviors.

[0055] The above is a description of the steps of the method for detecting friction-induced defects based on the lifetime of interlayer excitons of two-dimensional materials provided by the present invention. From the description of the above steps, it can be seen that according to the method for detecting friction-induced defects based on the lifetime of interlayer excitons of two-dimensional materials provided by the present invention, the surface of the target object is scanned by using a pulsed laser, and the interlayer exciton signal generated by the excitation of each region in multiple regions on the surface of the target object is obtained; the photoluminescence decay rate corresponding to each region is determined based on the interlayer exciton signal excited in each region, and the photoluminescence decay rate corresponding to each region is compared with a pre-calibrated standard rate to generate a comparison result; when the comparison result indicates that the photoluminescence decay rate corresponding to any target region is less than the standard rate, it is determined that the target region has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate. It can be seen that the present invention detects the change of exciton lifetime during friction by time-resolved photoluminescence spectroscopy to achieve high-precision detection of friction-induced defects.

[0056] The device for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers provided by the present invention is described below. The device for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers described below and the method for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers described above can be referenced to each other.

[0057] Fig.15 is a schematic diagram of the structure of a device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers provided by the present invention, such as Fig.15 As shown, the device provided by the present invention for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers includes: An acquisition module 1501 is used to scan the surface of a target object using a pulsed laser, and acquire an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; A comparison module 1502 is used to determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited by each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; The determination module 1503 is used to determine that a friction defect exists in any target area when the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0058] The device for detecting friction-induced defects based on the interlayer exciton lifetime of two-dimensional materials provided by the present invention uses a pulsed laser to scan the surface of a target object, and obtains an interlayer exciton signal generated by the excitation of each region in multiple regions on the surface of the target object; determines the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compares the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; when the comparison result indicates that the photoluminescence decay rate corresponding to any target region is less than the standard rate, it is determined that the target region has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate. It can be seen that the present invention detects the change of the exciton lifetime during the friction process through time-resolved photoluminescence spectroscopy to achieve high-precision detection of friction-induced defects.

[0059] Based on the above embodiment, in this embodiment, the acquisition module 1501 is specifically used for: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

[0060] Based on the above embodiment, in this embodiment, the comparison module 1502 is specifically used for: A time-resolved photoluminescence decay curve corresponding to each region is fitted based on the interlayer exciton signal excited in each region, and a photoluminescence decay rate corresponding to each region is calculated based on the time-resolved photoluminescence decay curve.

[0061] Based on the above embodiment, in this embodiment, the device further includes a fitting module, which is specifically used for: Performing convolution processing on the interlayer exciton signal excited in each region to obtain a processed interlayer exciton signal, and fitting the processed interlayer exciton signal using a single exponential decay function to obtain the time-resolved photoluminescence decay curve; The convolution process is used to influence the instrument response function.

[0062] Based on the above embodiment, in this embodiment, the device further includes a calibration module, which is specifically used for: A load of a first preset pressure value is applied to the surface of the two-dimensional material to be calibrated, and the load applied to the surface of the two-dimensional material to be calibrated is gradually reduced to a second preset pressure value, and calibration is performed using a wedge grating method to obtain the standard rate.

[0063] Fig.16 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.16 As shown, the electronic device may include: a processor 1610, a communication interface 1620, a memory 1630 and a communication bus 1640, wherein the processor 1610, the communication interface 1620 and the memory 1630 communicate with each other through the communication bus 1640. The processor 1610 may call the logic instructions in the memory 1630 to execute the method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, including: Scanning the surface of the target object using a pulsed laser, and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, it is determined that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0064] In addition, the logic instructions in the above-mentioned memory 1630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0065] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the method for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers provided by the above methods, including: Scanning the surface of the target object using a pulsed laser, and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, it is determined that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0066] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the method for detecting friction-induced defects based on the lifetime of excitons between two-dimensional material layers provided by the above methods is implemented, including: Scanning the surface of the target object using a pulsed laser, and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, it is determined that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

[0067] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0068] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, characterized in that: include: Scanning the surface of the target object using a pulsed laser, and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; Determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; When the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate, it is determined that the target area has a friction defect; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

2. The method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers according to claim 1, characterized in that: The method of scanning the surface of the target object using a pulsed laser and acquiring an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object comprises: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

3. The method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers according to claim 1 or 2, characterized in that: The method of determining the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region comprises: A time-resolved photoluminescence decay curve corresponding to each region is fitted based on the interlayer exciton signal excited in each region, and a photoluminescence decay rate corresponding to each region is calculated based on the time-resolved photoluminescence decay curve.

4. The method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers according to claim 3, characterized in that: The method of fitting the time-resolved photoluminescence decay curve corresponding to each region based on the interlayer exciton signal excited in each region comprises: Performing convolution processing on the interlayer exciton signal excited in each region to obtain a processed interlayer exciton signal, and fitting the processed interlayer exciton signal using a single exponential decay function to obtain the time-resolved photoluminescence decay curve; The convolution process is used to influence the instrument response function.

5. The method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers according to claim 1, characterized in that: The standard rate is calibrated based on the following steps: A load of a first preset pressure value is applied to the surface of the two-dimensional material to be calibrated, and the load applied to the surface of the two-dimensional material to be calibrated is gradually reduced to a second preset pressure value, and calibration is performed using a wedge grating method to obtain the standard rate.

6. A device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers, characterized in that: include: An acquisition module, used to scan the surface of the target object using a pulsed laser, and acquire an interlayer exciton signal generated by excitation in each of a plurality of regions on the surface of the target object; A comparison module, used to determine the photoluminescence decay rate corresponding to each region based on the interlayer exciton signal excited in each region, and to compare the photoluminescence decay rate corresponding to each region with a pre-calibrated standard rate to generate a comparison result; A determination module is used to determine that a friction defect exists in any target area when the comparison result indicates that the photoluminescence decay rate corresponding to any target area is less than the standard rate; wherein the friction force on the surface of the target object is positively correlated with the photoluminescence decay rate.

7. The device for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers according to claim 6, characterized in that: The acquisition module is specifically used for: Scanning the surface of the target object using a pulsed laser, and acquiring an excitation signal generated by each of a plurality of regions being excited; The excitation signal is filtered using a bandpass filter to obtain an interlayer exciton signal generated by the excitation of each of the multiple regions; wherein the filtering process is used to filter out the A exciton signal generated by the disulfide.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers as described in any one of claims 1 to 5 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers as described in any one of claims 1 to 5 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for detecting friction-induced defects based on the exciton lifetime between two-dimensional material layers as described in any one of claims 1 to 5 is implemented.

Images