CN114184585A - Method for detecting nano-scale defects in micromechanical interfaces - Google Patents
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Abstract
The invention provides a method for detecting nano-scale defects in a micromechanical interface, which comprises the following steps: providing a raw micromechanical interface material sample; carrying out plasma treatment on an original micromechanical interface material sample, and sequentially carrying out different plasma treatment times to control the defect type; and (3) carrying out fluorescence lifetime imaging on the micromechanical interface material sample at the original plasma processing time and at different plasma processing times through a fluorescence lifetime imaging system. The fluorescence lifetime imaging system is based on a single photon counting principle, has the advantages of high time resolution, high imaging speed and the like, can quickly detect a micro-mechanical interface containing defects, has low requirements on samples, does not need a specific sample substrate, and can monitor the fluorescence lifetime of the samples on any substrate. The fluorescence lifetime imaging system monitors the fluorescence lifetime change of the micromechanical interface material sample under different plasma processing time, so that the influence of different defect types on the fluorescence lifetime can be intuitively known, and theoretical guidance is provided for optimizing the performance of related elements.
Description
Technical Field
The invention relates to the technical field of micro-mechanical interface defect detection, in particular to a method for detecting a nano-scale defect in a micro-mechanical interface.
Background
The single-layer tungsten disulfide is a typical novel semiconductor material, has a wider electronic band structure and higher quantum yield, and can be used for developing novel low-power Light-emitting diodes (LEDs). One important parameter determining the luminous efficiency of an LED is the internal quantum yield of the LED, which is directly determined by the fluorescence lifetime of the carriers.
However, in the single layer tungsten disulfide manufacturing process, various types of defects are inevitably encountered, including: vacancy, substitution, interstitial defects, and the like. In previous studies, it was found that vacancy defects can be passivated by means of oxygen plasma treatment. If the single layer of tungsten disulfide prepared by the micromechanical stripping process is treated with an oxygen plasma, vacancy defects generated during the stripping process can be passivated. However, too short an oxygen plasma treatment time increases the density of sulfur vacancy defects; and if the oxygen plasma treatment time is too long, oxygen is introduced into the single-layer tungsten disulfide to replace disulfide vacancy defects. Different defects introduced in the oxygen plasma treatment process can be used as a trapping center of a current carrier in tungsten disulfide, so that the fluorescence lifetime is seriously influenced, and further the internal quantum yield of the LED is reduced.
The defect detection of the current micromechanical interface material can be characterized by scanning transmission electron microscopy and steady-state Photoluminescence spectroscopy (PL).
However, the scanning transmission electron microscope has extremely high requirements on sample preparation, and the sample is not easy to obtain. Secondly, the time for monitoring the defects by using a scanning transmission electron microscope is long, and the time cost is high.
For PL spectrum, although it can perform spectrum collection and photon imaging on defects in a single layer of tungsten disulfide, PL spectrum imaging can only obtain steady-state luminescence characteristics, which are the result after averaging, and cannot obtain the retention time of excitons in the material in an excited state, nor reflect the influence of defect type on the lifetime of fluorescence emitted by excitons.
Therefore, in the micromechanical interface material with the nanoscale thickness of the defects, the oxygen plasma treatment time is still challenging for the carrier lifetime, and it is important to know how the nanoscale defects influence the carrier fluorescence lifetime when optimizing the luminescence performance of the LED with the single-layer TMD (Transition-Metal Dichalcogenide).
Therefore, it is desirable to provide a novel method for detecting nanoscale defects in a micromechanical interface that can address at least one of the above-mentioned problems.
Disclosure of Invention
The invention aims to provide a method for detecting nano-scale defects in a micro-mechanical interface, which can perform fluorescence lifetime imaging on a micro-mechanical interface material sample which is originally and passes through different plasma processing time through a fluorescence lifetime imaging system, so that the effect of the plasma processing time on the fluorescence lifetime can be quickly obtained.
The invention provides a method for detecting nano-scale defects in a micromechanical interface, which comprises the following steps:
providing a raw micromechanical interface material sample;
carrying out plasma treatment on an original micromechanical interface material sample, and sequentially carrying out different plasma treatment times to control the defect types in the micromechanical interface material sample under different plasma treatment times;
and (3) carrying out fluorescence lifetime imaging on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time through a fluorescence lifetime imaging system so as to obtain the fluorescence lifetime of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
According to the method for detecting the nanoscale defects in the micromechanical interface, the fluorescence lifetime is obtained through a fluorescence lifetime image or a fluorescence lifetime attenuation curve.
The method for detecting the nanoscale defects in the micromechanical interface further comprises the following steps:
and performing Raman detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain Raman spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
The method for detecting the nanoscale defects in the micromechanical interface further comprises the following steps:
and carrying out steady-state photoluminescence spectrum detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain steady-state photoluminescence spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
According to the method for detecting the nanometer-scale defects in the micro-mechanical interface, the fluorescence lifetime imaging is carried out on the original micro-mechanical interface material sample and the micro-mechanical interface material sample under different plasma processing time by the fluorescence lifetime imaging system, and the method comprises the following steps:
placing and fixing a sample on a piezoelectric displacement table;
opening a laser controller, controlling the laser to emit laser, and focusing the laser to the sample through an excitation light path to realize excitation of the sample;
the excited sample emits fluorescence, and the emitted fluorescence signal enters a single photon detector through an emission light path;
the single-photon detector is used for detecting optical signals, the single-photon counter is used for synchronizing the single-photon detector, the laser controller and the piezoelectric displacement table, and the piezoelectric displacement table is used for moving a sample to scan to obtain a fluorescence life image.
According to the method for detecting the nanoscale defects in the micromechanical interface, the fluorescence lifetime decay curve is fitted by using an exponential function, the exponential function comprises a double-exponential function and a single-exponential function,
wherein the fluorescence lifetime obtained by fitting the bi-exponential function is determined by the fluorescence lifetime tau of the direct transition A exciton1And fluorescence lifetime of the triplet exciton2It was determined that the fluorescence lifetime fitted by the single exponential function was determined from the fluorescence lifetime τ of the direct transition a exciton.
The method for detecting the nanoscale defects in the micromechanical interface further comprises the following steps:
and performing weighted calculation on the fluorescence lifetime after the exponential function fitting to obtain an average fluorescence lifetime so as to obtain an average fluorescence lifetime change curve of the micromechanical interface material sample along with the change of the plasma processing time.
According to the method for detecting the nanoscale defects in the micromechanical interface, provided by the invention, the plasma treatment comprises oxygen plasma treatment, nitrogen plasma treatment or argon plasma treatment.
According to the method for detecting the nanoscale defects in the micromechanical interface, provided by the invention, the micromechanical interface material sample comprises a transition metal sulfide sample, and the number of layers of the transition metal sulfide sample is in the range of 1-4.
According to the method for detecting the nanoscale defects in the micromechanical interface, the plasma treatment is oxygen plasma treatment, and the defect types comprise sulfur vacancy defects, oxygen-substituted sulfur vacancy defects and oxygen-substituted disulfide vacancy defects.
The invention provides a method for detecting nano-scale defects in a micromechanical interface, which comprises the following steps: providing a raw micromechanical interface material sample; carrying out plasma treatment on an original micromechanical interface material sample, and sequentially carrying out different plasma treatment times to control the defect types in the micromechanical interface material sample under different plasma treatment times; and (3) carrying out fluorescence lifetime imaging on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time through a fluorescence lifetime imaging system so as to obtain the fluorescence lifetime of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time. By the arrangement, the fluorescence lifetime imaging system is based on the single photon counting principle, has the advantages of high time resolution, high imaging speed and the like, can quickly detect a micro-mechanical interface containing defects such as single-layer tungsten disulfide, has low requirements on samples, does not need a specific sample substrate, and can monitor the fluorescence lifetime of the samples on any substrate. The fluorescence lifetime imaging system monitors the fluorescence lifetime change of the micro-mechanical interface material sample under different plasma processing time, can quickly and intuitively know the influence of different defect types on the fluorescence lifetime, and provides theoretical guidance for optimizing related elements, particularly near-infrared light-emitting diodes.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is an image of a sample of a raw micromechanical interface material provided in accordance with the present invention under an optical microscope;
FIG. 2 is a Raman spectrum of a sample of a micromechanical interface material provided in accordance with the present invention, both raw and at different oxygen plasma treatment times;
FIG. 3 is a steady state photoluminescence spectrum of a sample of a micromechanical interface material provided by the present invention at different oxygen plasma treatment times;
FIG. 4 is a schematic diagram of a fluorescence lifetime imaging system provided by the present invention;
FIG. 5 is a fluorescence lifetime image of a sample of an original micromechanical interface material provided in accordance with the present invention;
FIG. 6 is a fluorescence lifetime image of a sample of the micromechanical interface material subjected to a first oxygen plasma treatment according to the present disclosure;
FIG. 7 is a fluorescence lifetime image of a sample of the micromechanical interface material subjected to a second oxygen plasma treatment according to the present disclosure;
FIG. 8 is a fluorescence lifetime image of a sample of the micromechanical interface material subjected to a third oxygen plasma treatment according to the present disclosure;
FIG. 9 is a fluorescence lifetime image of a sample of a micromechanical interface material according to the present disclosure after a fourth oxygen plasma treatment;
FIG. 10 is a fluorescence lifetime image of a sample of a micro-mechanical interface material subjected to a fifth oxygen plasma treatment provided by the present invention;
FIG. 11 is a fluorescence lifetime image of a sample of a micro-mechanical interface material subjected to a sixth oxygen plasma treatment provided in the present disclosure;
FIG. 12 is a fluorescence lifetime image of a sample of a micromechanical interface material subjected to a seventh oxygen plasma treatment according to the present disclosure;
FIG. 13 is a fluorescence lifetime image of a sample of a micromechanical interface material subjected to an eighth oxygen plasma treatment according to the present disclosure;
FIG. 14 is a fluorescence lifetime image of a sample of a micromechanical interface material subjected to a ninth oxygen plasma treatment according to the present disclosure;
FIG. 15 is a fluorescence lifetime image of a sample of a micromechanical interface material subjected to a tenth oxygen plasma treatment according to the present disclosure;
fig. 16 is a graph of fluorescence lifetime decay of the original micromechanical interface material sample and the micromechanical interface material sample after the first oxygen plasma treatment to the fourth oxygen plasma treatment and a fitting graph thereof according to the present disclosure;
FIG. 17 is a graph of fluorescence lifetime decay of a sample of a micro-mechanical interface material treated with oxygen plasma from the fifth time to the tenth time and a graph fitted with the graph, according to the present invention;
FIG. 18 is a graph of the fluorescence lifetime of samples of micromechanical interface materials at different oxygen plasma treatment times, as a function of oxygen plasma treatment time, obtained by weighted averaging, according to the present disclosure;
reference numerals:
1: a laser controller; 2: a laser; 3: an excitation light path;
4: a sample; 5: an emission light path; 6: a single photon detector;
7: a single photon counter; 8: a piezoelectric displacement stage; 9: and (4) a terminal.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The method of detecting nanoscale defects in a micromechanical interface of the present invention is described below with reference to fig. 1-18.
The embodiment of the invention provides a method for detecting nano-scale defects in a micromechanical interface, which comprises the following steps:
providing a raw micromechanical interface material sample;
carrying out plasma treatment on an original micromechanical interface material sample, and sequentially carrying out different plasma treatment times to control the defect types in the micromechanical interface material sample under different plasma treatment times;
and (3) carrying out fluorescence lifetime imaging on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time through a fluorescence lifetime imaging system so as to obtain the fluorescence lifetime of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time. The fluorescence lifetime refers to the time of the exciton in the excited state in the material, and the time scale is in the order of nanoseconds.
With such a configuration, the Fluorescence Lifetime Imaging Microscope (FLIM) is based on the single photon counting principle, and has the advantages of high time resolution, fast Imaging speed, and the like, for example, for an acquired image with a spatial pixel of 512 × 512pixel and an acquisition range of 80 × 80 μm, the acquisition time is only 11 minutes, so that the micro-mechanical interface containing defects can be rapidly detected. And FLIM has low requirements on samples, does not need a specific sample substrate, and can monitor the fluorescence lifetime of samples on any substrate. The fluorescence lifetime imaging system monitors the fluorescence lifetime change of the micro-mechanical interface material sample under different plasma processing time, can quickly and intuitively know the influence of different defect types on the fluorescence lifetime, and provides theoretical guidance for optimizing related elements, particularly near-infrared light-emitting diodes.
In the embodiment of the present invention, the sample of the micromechanical interface material includes a transition metal sulfide sample, and the number of layers of the transition metal sulfide sample is in a range from 1 to 4, such as a single layer of tungsten disulfide, but not limited to tungsten disulfide. That is to say, the fluorescence lifetime imaging system can detect the fluorescence lifetime of the single-layer and few (less than or equal to 4) transition metal sulfides after plasma treatment, and provides guidance for optimizing the performance of the single-layer tungsten disulfide-based elements such as the LED.
The plasma treatment includes oxygen plasma treatment, nitrogen plasma treatment, or argon plasma treatment. The transition metal sulfide treated by the plasma can measure the fluorescence lifetime of a sample through a fluorescence lifetime imaging system, so that the defect and the defect type of the sample can be rapidly detected.
In the embodiment of the invention, oxygen plasma treatment is performed on an original micromechanical interface material sample, and the oxygen defect type in a micromechanical interface such as a single layer of tungsten disulfide is controlled by controlling the oxygen plasma treatment time. Specifically, the oxygen defect types include a sulfur vacancy defect, an oxygen-substituted sulfur vacancy defect, and an oxygen-substituted double sulfur vacancy defect. The fluorescence lifetime is sensitive to the type of oxygen defects, and once oxygen defects are introduced into the sample, the fluorescence lifetime of a monolayer of tungsten disulfide can be reduced by an order of magnitude. And different defects have different effects on the intensity and the service life of fluorescence, so that the tungsten disulfide containing different oxygen defects can be subjected to fluorescence lifetime imaging through FLIM.
To detect whether the oxygen plasma treatment damaged the molecular structure of the tungsten disulfide, a raman test of the sample was required. Therefore, in an embodiment of the present invention, the method for detecting the nanoscale defect in the micromechanical interface further includes: and performing Raman detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain Raman spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time. Referring to fig. 2, raman spectra of a single layer of tungsten disulfide are shown for the original and at different oxygen plasma treatment times. In order to ensure strong contrast of the Raman peak, the Raman peak under different oxygen plasma treatment time is normalized by adopting the silicon peak. The Raman characteristic mode A of the monolayer tungsten disulfide after the oxygen plasma treatment can be seen through Raman spectrum1gNone of the intensities of LA (M), LA (M) and LA (M) were significantly reduced or lost. Thus, it is subjected to oxygen plasma treatment for 3s-30sThe molecular structure of the single-layer tungsten disulfide is not damaged, and the detection result is not influenced.
It should be noted that, in order to further confirm whether oxygen defects are introduced after the oxygen plasma treatment, in an embodiment of the present invention, the method for detecting nanoscale defects in a micromechanical interface further includes: and carrying out steady-state photoluminescence spectrum detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain steady-state photoluminescence spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time. Referring to fig. 3, a plot of the steady state Photoluminescence (PL) spectra for a single layer of tungsten disulfide as received and at various oxygen plasma treatment times. The PL spectrum is used to identify the type of oxygen defect to confirm whether an oxygen defect is introduced. The PL spectral detection conditions were: the type of the detection instrument is Horiba HR Evolution, the wavelength of a laser is 523nm, and the spectral resolution is 0.5cm-1The laser power intensity was 6.6 mW.
As shown in fig. 3, the original monolayer tungsten disulfide sample showed a neutral a exciton PL peak at 2.02eV, corresponding to the direct band gap of the brillouin zone K point. The PL spectrum shows a significant change as the oxygen plasma treatment time increases: when the oxygen plasma treatment time is 3s, the PL intensity is rapidly reduced compared with the original sample intensity, and the red shift phenomenon of the PL peak of the A exciton is accompanied, namely the peak value is moved to the direction with low energy, at the moment, in the single-layer tungsten disulfide sample, sulfur atoms are lost due to the bombardment of oxygen plasma, so that sulfur vacancy defects are generated in the sample, and defect energy levels are introduced into an electron energy band structure, so that the fluorescence emission intensity of band edge direct transition A exciton is reduced.
When the oxygen plasma treatment time is 6s-15s, the PL peak intensity of the a exciton gradually increases, accompanied by a phenomenon of first red-shifting (6s-2s) and then blue-shifting (12s-15s) of the PL peak. During this treatment period, a portion of the sulfur vacancies are replaced with oxygen ions, such that a portion of the sulfur vacancy defects of the material are passivated, forming oxygen-substituted sulfur vacancy defects, thus creating an increase in PL fluorescence intensity of band-edge direct transition a excitons.
When the oxygen plasma treatment time is 18s to 30s, the intensity of the A exciton PL continuously decreases, and the red shift phenomenon of the PL peak is accompanied. The reasons for this phenomenon are: as the oxygen plasma treatment time is further increased, while a portion of the sulfur vacancies are passivated by oxygen ions, as oxygen ions are injected, the sulfur vacancies in the sample increase with more sulfur vacancy defects than oxygen replacement sulfur vacancy defects, forming oxygen replacement double sulfur vacancy defects, which defect type still introduces a defect level in the electron band structure, resulting in a reduction in the band edge a exciton PL intensity. Thus, it can be seen from PL spectroscopy that different oxygen plasma treatments introduce different oxygen defect types.
In the embodiment of the invention, as shown in fig. 4, the fluorescence lifetime imaging system (FLIM) includes a laser controller 1, a laser 2, a single photon detector 6, a single photon counter 7, a piezoelectric displacement table 8, and the like. The working procedure for fluorescence lifetime imaging by FLIM is as follows:
firstly, a sample 4 is placed and fixed on a piezoelectric displacement table 8, then a laser controller 1 is opened, and a laser 2 is controlled to emit laser, wherein the laser wavelength is 405nm, and the repetition frequency is 40 MHz. The laser light is focused to the sample 4 through the excitation light path 3 to realize excitation of the sample 4. In the excitation light path 3, an objective lens with a magnification of 100 times and a numerical aperture of 0.9 is used to focus the excitation light. The excited sample 4 emits fluorescence, and the emitted fluorescence signal passes through the same objective lens and then enters the single photon detector 6 through the emission light path 5.
Then, a single photon detector 6 is used for detecting optical signals, the single photon detector 6 converts the collected photon signals into electric signals, and the electric signals are sent to a single photon counter 7 through a signal line. And then, synchronizing the single-photon detector 6, the laser controller 1 and the piezoelectric displacement table 8 by using the single-photon counter 7, and moving the sample 4 by using the piezoelectric displacement table 8 to scan to obtain a fluorescence life image. The single photon counter 7 can record the number of photons in a plurality of laser pulse periods, wherein the number of laser pulse periods is sent to the single photon counter 7 by the laser controller 1 through a signal line. For the purpose of realizing fluorescence lifetime imaging, the system adopts a method of scanning imaging of the piezoelectric displacement table 8, namely, excitation light is fixed, and scanning in an XY plane of a sample is realized through the movement of the piezoelectric displacement table 8. The position signal of the piezoelectric displacement table 8 is transmitted to the single photon counter 7 through a signal line, so that the photon signal at each position (pixel point) is recorded. In addition, the system also comprises a terminal 9 such as a computer, special software is installed on the computer, the piezoelectric displacement table 8, the single photon counter 7 and the laser controller 1 are all connected with the terminal 9 through signal lines, and the working state of the system is controlled through the special software.
Referring to fig. 1, a single layer of tungsten disulfide is illustrated, and the single layer of tungsten disulfide is shown under an optical microscope in a dashed line frame in fig. 1. The single-layer tungsten disulfide can be prepared by a micromechanical stripping method, namely, the single-layer tungsten disulfide is stripped to SiO from the bulk tungsten disulfide crystal by the micromechanical stripping method2On a substrate or on a Si substrate. After preparing and obtaining the monolayer tungsten disulfide, placing a sample in an oxygen plasma processing cavity for processing, wherein the processing conditions are as follows: the purity of the oxygen gas is 99.99 percent, the flow rate of the oxygen gas is 200sccm, and the oxygen plasma is generated under the radio frequency of 13.65MHz and the power of 4W. The oxygen plasma treatment time was 3 seconds for the samples treated once for a total of 10 treatments, and thus the tungsten disulfide samples were treated for the following times in order: 3s, 6s, 9s, 12s, 15s, 18s, 21s, 24s, 27s, 30 s. Wherein, the oxygen plasma treatment time can be specifically determined according to the actual detection requirement.
In the embodiment of the invention, a fluorescence lifetime image or a fluorescence lifetime attenuation curve can be obtained by a fluorescence lifetime imaging system. The different colors on the fluorescence lifetime image represent the length of the fluorescence lifetime, and the change of the fluorescence lifetime of the sample can be visually observed, referring to fig. 5 to 15, which are fluorescence lifetime images of the single layer of tungsten disulfide after the original and different oxygen plasma treatment times, respectively. The upper, right, black and white color scale in the figure represents the number of fluorescence photons collected, and the lower, right, color scale in the figure represents the magnitude of the mean fluorescence lifetime. From the above figures, the average fluorescence lifetime of a single layer of tungsten disulfide was directly observed as a function of oxygen plasma treatment time by FLIM. The average lifetime of the untreated virgin tungsten disulfide was close to 1.3ns, showing red fluorescence lifetime imaging. And once oxygen plasma treated, the mean fluorescence lifetime decays rapidly by an order of magnitude, approaching 0.2ns, showing blue fluorescence lifetime imaging. As the treatment time increases, the average fluorescence lifetime decreases with a concomitant decrease in the number of fluorescence photons.
In the embodiment of the invention, the fluorescence lifetime decay curve is fitted by using an exponential function, and the exponential function comprises a double-exponential function and a single-exponential function. Wherein the fluorescence lifetime obtained by fitting the double exponential function is determined by the fluorescence lifetime tau of the direct transition A exciton1And fluorescence lifetime of the triplet exciton2It was determined that the fluorescence lifetime fitted to a single exponential function was determined from the fluorescence lifetime τ of the direct transition a exciton. Referring to fig. 16 and 17, the fluorescence lifetime decay curves and the fitted curves of the monolayer tungsten disulfide are shown for the original and the different oxygen plasma treatment times. The gray shaded area of the graph is the Instrument Response Function (IRF), and the direction indicated by the arrow represents the direction of decrease in fluorescence lifetime. Oxygen defects caused by a monolayer of tungsten disulfide after oxygen plasma treatment at different times can result in changes in fluorescence lifetime in the sample.
As shown in fig. 16, the light blue curve represents the raw curve of fluorescence decay within 12s (including 12s) before plasma processing collected by the single photon detector. Before the original curve is subjected to exponential function fitting, deconvolution processing needs to be carried out after IRF subtraction. The decay curve of the fluorescence lifetime was a bi-exponential function for the first 12s of the oxygen plasma treatment (including 12s)
And (6) fitting. Wherein, tau1、τ2Respectively, the fluorescence lifetimes of the direct transition a exciton, the triplet exciton (trion). A. the1、A2To fit the curve amplitude components, the number weights of the a excitons and the trions (trions) are represented, respectively. Short life time tau1(specific gravity is large) due to the fluorescence lifetime of A excitons, while longer lifetime τ2(the specific gravity is small) due to the fluorescence lifetime of the triplet excitons. According to the PL spectrum shown in FIG. 3, when the oxygen plasma treatment time was 12sThe internal (containing 12s), PL peak exhibits asymmetric characteristics, i.e. the PL peak contains both a large number of a excitons and a small number of trions. Thus, within the first 12s (including 12s), the fluorescence lifetime was fitted using a bi-exponential function. In contrast, as shown in fig. 17, during the 15s-30s treatment period, charge transfer occurs due to bombardment by the oxygen plasma, i.e., excess electrons in the trions are transferred into the neutral a excitons. Therefore, the fluorescence lifetime adopts a single exponential function Ae within the 15s-30s time period-t/τAnd (6) fitting. Where τ represents the fluorescence lifetime of the direct transition A exciton and A is the fitted curve amplitude component.
In an embodiment of the present invention, the method for detecting a nanoscale defect in a micromechanical interface further includes: and performing weighted calculation on the fluorescence lifetime after exponential function fitting to obtain an average fluorescence lifetime so as to obtain an average fluorescence lifetime change curve of the micromechanical interface material sample along with the change of the plasma processing time. Referring to fig. 18, the fluorescence lifetimes of the original and oxygen plasma treated monolayers of tungsten disulfide, obtained as a weighted average after exponential fitting, vary with oxygen plasma treatment time. The weighted average fluorescence lifetime after double exponential fitting is given by the formula: a. the1τ1+A2τ2/A1+A2. The mean fluorescence lifetime after single exponential fitting is τ.
The lifetime of the band edge fluorescence detected by FLIM was 1.3 nanoseconds when the monolayer of tungsten disulfide was not bombarded by plasma. After the oxygen plasma bombards the tungsten disulfide for 3 seconds, the fluorescence lifetime is rapidly reduced by 61.5 percent and reaches 0.5 nanosecond, at the moment, the S-W bond in the single-layer tungsten disulfide is broken due to the bombardment of oxygen ions, so that a sulfur atom vacancy defect is formed, a defect energy level is formed in a forbidden band, and the non-radiative recombination of an electron-defect energy level is accelerated. As the plasma bombardment time increased, the fluorescence lifetime exhibited a monotonically decreasing trend and decreased to 0.2 nanoseconds at 12 seconds. When the bombardment time is 15 seconds to 24 seconds, the sulfur vacancies are replaced by oxygen, thereby forming oxygen-substituted sulfur vacancy doped defects in the tungsten disulfide. Oxygen replacing the sulfur vacancies leads to a 60% increase in fluorescence lifetime compared to the sulfur vacancy defects, and the fluorescence lifetime remains essentially unchanged with this defect type predominating, i.e. in the range of 15 seconds to 24 seconds. When the plasma bombardment time was further increased, at which time oxygen-substituted disulfur vacancy defects predominated, the fluorescence lifetime again showed a decreasing trend and decreased to 0.21 ns at the 30 th second.
Therefore, according to FLIM results, the change of the fluorescence lifetime with the bombardment time in tungsten disulfide with different types of defects dominating presents different characteristics, especially for oxygen replacing sulfur vacancy defects, and the fluorescence lifetime is independent of the bombardment time. For defect types containing sulfur vacancies, however, the fluorescence lifetime has a monotonically decreasing trend with bombardment time and decreases by nearly an order of magnitude compared to tungsten disulfide without defects.
In summary, the embodiments of the present invention provide a method for detecting nanoscale defects in a micro-mechanical interface, which uses a fluorescence lifetime imaging system based on a single photon technical principle to perform fluorescence lifetime imaging on an original micro-mechanical interface containing defects, such as a single layer of tungsten disulfide, and can quickly obtain corresponding fluorescence lifetime values under different oxygen plasma processing times, thereby providing theoretical guidance for optimizing the performance of related components, particularly light emitting diodes. The method has low requirements on samples, does not need a specific sample substrate, and can monitor the fluorescence lifetime of the samples on any substrate. Once oxygen defects are introduced into a sample, the fluorescence lifetime of the single-layer tungsten disulfide can be reduced by one order of magnitude, different defects have different effects on the intensity and lifetime of fluorescence, the fluorescence lifetime is sensitive to the type of the oxygen defects, and the presence or absence of the oxygen defects and the types of the oxygen defects can be rapidly detected. Of course, the method can also be used for detecting the fluorescence lifetime of a single layer or a few layers (less than or equal to 4 layers) of tungsten disulfide after nitrogen plasma and argon plasma treatment. The micromechanical interface material should satisfy the application range of a fluorescence lifetime imaging system and can emit fluorescence.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for detecting nanoscale defects in a micromechanical interface, comprising the steps of:
providing a raw micromechanical interface material sample;
carrying out plasma treatment on an original micromechanical interface material sample, and sequentially carrying out different plasma treatment times to control the defect types in the micromechanical interface material sample under different plasma treatment times;
and (3) carrying out fluorescence lifetime imaging on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time through a fluorescence lifetime imaging system so as to obtain the fluorescence lifetime of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
2. The method for detecting nanoscale defects in micromechanical interfaces according to claim 1, characterized in that the fluorescence lifetime is obtained by fluorescence lifetime images or fluorescence lifetime decay curves.
3. The method of detecting nanoscale defects in micromechanical interfaces of claim 1, further comprising:
and performing Raman detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain Raman spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
4. The method of detecting nanoscale defects in micromechanical interfaces of claim 1, further comprising:
and carrying out steady-state photoluminescence spectrum detection on the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time to obtain steady-state photoluminescence spectrograms of the original micromechanical interface material sample and the micromechanical interface material sample under different plasma processing time.
5. The method for detecting nanoscale defects in micromechanical interfaces according to claim 1, wherein said fluorescence lifetime imaging of the original micromechanical interface material sample and the micromechanical interface material sample at different plasma processing times by means of a fluorescence lifetime imaging system comprises the following steps:
placing and fixing a sample on a piezoelectric displacement table;
opening a laser controller, controlling the laser to emit laser, and focusing the laser to the sample through an excitation light path to realize excitation of the sample;
the excited sample emits fluorescence, and the emitted fluorescence signal enters a single photon detector through an emission light path;
the single-photon detector is used for detecting optical signals, the single-photon counter is used for synchronizing the single-photon detector, the laser controller and the piezoelectric displacement table, and the piezoelectric displacement table is used for moving a sample to scan to obtain a fluorescence life image.
6. The method of detecting nanoscale defects in micromechanical interfaces according to claim 2, characterized in that said fluorescence lifetime decay curve is fitted with an exponential function, said exponential function comprising a bi-exponential function and a mono-exponential function,
wherein the fluorescence lifetime obtained by fitting the bi-exponential function is determined by the fluorescence lifetime tau of the direct transition A exciton1And fluorescence lifetime of the triplet exciton2It was determined that the fluorescence lifetime fitted by the single exponential function was determined from the fluorescence lifetime τ of the direct transition a exciton.
7. The method of detecting nanoscale defects in micromechanical interfaces of claim 6, further comprising:
and performing weighted calculation on the fluorescence lifetime after the exponential function fitting to obtain an average fluorescence lifetime so as to obtain an average fluorescence lifetime change curve of the micromechanical interface material sample along with the change of the plasma processing time.
8. The method of claim 1, wherein the plasma treatment comprises an oxygen plasma treatment, a nitrogen plasma treatment, or an argon plasma treatment.
9. The method for detecting nanoscale defects in micromechanical interfaces according to claim 1, characterized in that the micromechanical interface material sample comprises a transition metal sulfide sample, the number of layers of the transition metal sulfide sample being in the range of 1-4.
10. The method of claim 8, wherein the plasma treatment is an oxygen plasma treatment, and the defect types include sulfur vacancy defects, oxygen-substituted sulfur vacancy defects, and oxygen-substituted double sulfur vacancy defects.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102998290A (en) * | 2012-11-14 | 2013-03-27 | 深圳大学 | Fluorescent lifetime microimaging system |
| CN109253992A (en) * | 2018-10-24 | 2019-01-22 | 中国空气动力研究与发展中心超高速空气动力研究所 | A kind of plasma fluorescence lifetime measurement device and method |
| CN110726701A (en) * | 2019-10-30 | 2020-01-24 | 清华大学 | Method for monitoring influence of defects in few-layer two-dimensional material on exciton transmission and application |
| WO2020155819A1 (en) * | 2019-01-31 | 2020-08-06 | 清华大学 | Method for characterizing defect in two-dimensional material and application thereof |
| CN113125363A (en) * | 2021-04-08 | 2021-07-16 | 清华大学 | Two-dimensional heterojunction material interface defect detection method and device |
| CN113937023A (en) * | 2021-08-31 | 2022-01-14 | 清华大学 | Method for testing defect influence energy transfer in two-dimensional material heterojunction |
-
2021
- 2021-10-27 CN CN202111264073.8A patent/CN114184585B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102998290A (en) * | 2012-11-14 | 2013-03-27 | 深圳大学 | Fluorescent lifetime microimaging system |
| CN109253992A (en) * | 2018-10-24 | 2019-01-22 | 中国空气动力研究与发展中心超高速空气动力研究所 | A kind of plasma fluorescence lifetime measurement device and method |
| WO2020155819A1 (en) * | 2019-01-31 | 2020-08-06 | 清华大学 | Method for characterizing defect in two-dimensional material and application thereof |
| CN110726701A (en) * | 2019-10-30 | 2020-01-24 | 清华大学 | Method for monitoring influence of defects in few-layer two-dimensional material on exciton transmission and application |
| CN113125363A (en) * | 2021-04-08 | 2021-07-16 | 清华大学 | Two-dimensional heterojunction material interface defect detection method and device |
| CN113937023A (en) * | 2021-08-31 | 2022-01-14 | 清华大学 | Method for testing defect influence energy transfer in two-dimensional material heterojunction |
Non-Patent Citations (3)
| Title |
|---|
| MENGFAN ZHOU等: "《How defects influence the photoluminescence of TMDCs》", 《NANO RESEARCH 》 * |
| SARA BARJA等: "《Identifying substitutional oxygen as a prolific point defect in monolayer transition metal dichalcogenides》", 《NATURE COMMUNICATIONS》 * |
| YUANSHUANG LIU等: "《Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe 2 revealed by fluorescence lifetime imaging measurement》", 《NANO RESEARCH》 * |
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