In-situ illumination KPFM testing device and testing method

Abstract

The invention discloses an in-situ illumination KPFM test device and a test method. The test device comprises a KPFM tester body; the KPFM tester body comprises a laser detector, a reflective mirror, a spectroscope, a laser and a sample table; laser emitted by the laser device sequentially passes through the spectroscope, the sample table and the reflective mirror and enters the laser detector; an additional light source is arranged at a position close to the sample table, and the distance between a light outlet of the additional light source and the sample table is 3-5cm; and a light filtering assembly is arranged at an inlet of the laser detector. According to the testing device, interference factors in the testing process can be effectively reduced while the authenticity of the testing environment is kept, so that the testing efficiency and precision are improved, and the accuracy and reliability of in-situ illumination testing through the KPFM are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of in-situ testing of micro-area surface potential, and relates to an in-situ illumination KPFM testing device and a testing method. Background Art

[0002] Kelvin probe force microscope (KPFM) is a derivative technology of atomic force microscope. An AC voltage is applied to the probe to form an electric field between the tip and the sample. A DC voltage is applied to offset the electric field, thereby observing the surface potential of the sample. In addition, the contact potential difference between the conductive tip and the sample V CPD (Contact potential difference) is defined as V CPD =( φ tip – φ sample ) / - e ,in φ sample and φ tip is the work function of the sample and the tip, e is the elementary charge. Therefore, when the tip work function and the contact potential difference are known, the work function of the sample can be obtained. KPFM has been applied to many fields for non-destructive detection of the local surface potential of samples under atmospheric conditions, such as local doping concentration measurement, band bending measurement near structural defects, and domain configuration in samples containing two different phases. KPFM can also obtain the spatial distribution of surface potential and work function, as well as their changes under illumination conditions. The surface potential is generated by the photoexcitation of carriers and the subsequent redistribution of static charges. Therefore, KPFM experiments will help to clarify the interaction between the surface potential excited by incident photons and the charge carriers in the active material. This is important for the mechanism research of photocatalysis, perovskite batteries, etc. The most common atomic force needle microscope is mainly composed of a laser system, a photoelectric detection system, a feedback system, a piezoelectric scanning system, a data processing and display system, and a seismic isolation system. In the photoelectric detection system, the laser hits the tip of the probe, and the bending deformation or vibration change of the microcantilever is optically amplified by the principle of optical lever, and then converted into an electrical signal by a photodetector for detection.

[0003] During the test, when studying the performance of materials under light excitation, it is necessary to conduct in-situ illumination testing, that is, to conduct KPFM surface potential measurement under the condition of external light source illumination to obtain the surface potential distribution of the sample and reflect the carrier distribution. However, the external light source will enter the laser detector, and the external light source entering the laser detector will interfere with the laser detection signal, and the topography will have serious noise. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides an in-situ illumination KPFM testing device and a testing method, thereby solving the problem that an external light source affects the test results when performing in-situ illumination testing using KPFM in the prior art.

[0005] The present invention is achieved through the following technical solutions: An in-situ illumination KPFM test device comprises a KPFM tester body; the KPFM tester body comprises a laser detector, a reflector, a beam splitter, a laser and a sample stage; the laser light emitted by the laser passes through the beam splitter, the sample stage and the reflector in sequence and enters the laser detector; An external light source is provided near the sample stage, and the distance between the light outlet of the external light source and the sample stage is 3-5 cm; A filter component is arranged at the entrance of the laser detector.

[0006] Preferably, the external light source is a Xe lamp, a white light LED lamp, an ultraviolet lamp or a red light lamp.

[0007] Preferably, when the external light source is a Xe lamp, the light outlet of the Xe lamp is provided with an optical fiber, and the distance between the light outlet of the optical fiber and the sample stage is 3 to 5 cm.

[0008] Preferably, the filter assembly includes a baffle or a filter; the baffle is provided with a through hole.

[0009] Preferably, the diameter of the through hole on the baffle is 1-2 mm.

[0010] Preferably, the filter includes any one of an absorption filter, a reflection filter, a composite filter and a bandpass filter.

[0011] Preferably, when the optical filter is a bandpass filter, the passband center wavelength of the optical filter is consistent with the wavelength of the laser emitted by the laser, and the passband half-width of the optical filter is 50 nm.

[0012] Preferably, a clamping and fixing component is provided at the entrance of the laser detector, and the filter component is arranged at the entrance of the laser detector of the KPFM tester body through the clamping and fixing component.

[0013] Preferably, the testing device further comprises a heat dissipation component, and the heat dissipation component is used to dissipate the heat generated by the external light source.

[0014] An in-situ illumination KPFM test method adopts the above-mentioned in-situ illumination KPFM test device and includes the following steps: turning on the KPFM tester body, controlling the distance between the light outlet of the external light source and the sample stage to be 3-5 cm, and turning on the external light source for testing.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses an in-situ illumination KPFM testing device. Firstly, an external light source is provided near a sample stage. The design of the external light source enables the testing device to simulate or provide the illumination conditions of the sample to be tested in an actual working environment, so as to more accurately reflect the performance of the sample to be tested in actual applications. By accurately simulating the actual working illumination, the performance of these materials can be more effectively evaluated. In addition, the distance between the light outlet of the external light source and the sample stage is controlled to be 3-5 cm, which effectively ensures that the external light source fully excites the sample to be tested during the test and ensures the sensitivity of the test result. Secondly, a filter component is provided at the entrance of the laser detector. The setting of the filter component can block or attenuate the external light. The wavelength of the light source that interferes with the laser detector helps to reduce noise and errors in the test process and improve the accuracy and reliability of the test. In the KPFM test, the laser detector is extremely sensitive to light, and any unnecessary interference may cause the test result to deviate from the true value. The precise filtering effect of the filter component can ensure that the laser detector only receives valid signals from the sample to be tested, thereby obtaining a more accurate test result. The present invention combines the design of an external light source and a filter component. The test device can effectively reduce interference factors in the test process while maintaining the authenticity of the test environment, thereby improving test efficiency and accuracy, and significantly improving the accuracy and reliability of in-situ illumination testing using KPFM.

[0016] Furthermore, the external light source is a Xe lamp, a white light LED lamp, an ultraviolet lamp or a red light lamp. The selection of multiple light sources provides a wider range of test conditions, so that the test device can simulate or provide a variety of different lighting environments; different samples to be tested are also more sensitive to specific wavelengths of light or have specific spectral responses. By setting up multiple light sources, the test device can more easily adapt to the test needs of different samples to be tested, thereby improving the pertinence and accuracy of the test.

[0017] Furthermore, when the external light source is a Xe lamp, the light outlet of the Xe lamp is provided with an optical fiber, and the distance between the light outlet of the optical fiber and the sample stage is 3 to 5 cm. The Xe lamp is guided by the optical fiber here, which on the one hand makes the light more fully and effectively concentrated on the sample surface for sample testing, and on the other hand avoids the light from entering the detector and affecting the detection results.

[0018] Furthermore, the filter assembly includes a baffle or filter with a through hole. First, by setting the through hole, the range of light irradiated by the external light source to the sample to be tested and the laser detector can be accurately controlled. This helps to reduce unnecessary light interference and ensure that only light information related to the test is received during the test, thereby improving the accuracy and reliability of the test. The design of the filter allows only light of a specific wavelength or range to pass, thereby blocking other wavelengths of light that may cause damage to the laser detector, which helps to reduce test errors caused by light interference and extend the service life of the laser detector. Through the setting of the filter assembly, the accuracy and reliability of the test are effectively improved.

[0019] Furthermore, the diameter of the through hole on the baffle is 1-2 mm. First, the through hole with a diameter of 1-2 mm can accurately control the amount of light passing through, avoiding excessive light from entering the test area, thereby reducing light interference and scattering, which helps to ensure that the laser detector receives a direct and clear light signal from the sample to be tested, thereby improving the accuracy and precision of the test. The through hole with a small diameter can effectively block stray light from outside the test area, which will interfere with the normal operation of the laser detector. By reducing the impact of stray light, the accuracy and reliability of the test can be further improved.

[0020] Further, the filter includes any one of an absorption filter, a reflection filter, a composite filter and a bandpass filter. Different types of filters have different filtering characteristics and can meet different test requirements. For example, the absorption filter achieves the filtering effect by absorbing light of a specific wavelength, and the reflection filter achieves the purpose by reflecting light of a specific wavelength. This diversified filtering effect enables the test device to cope with a variety of test scenarios and test requirements. The filter can accurately control the wavelength and intensity of the light passing through, thereby reducing light interference and scattering, and improving the accuracy and reliability of the test. Different types of filters have different adaptability to light sources and test environments. For example, a bandpass filter allows light of a specific wavelength range to pass, while light of other wavelengths is suppressed, which makes it particularly suitable for test scenarios that require a specific wavelength light source. Therefore, this setting enables the test device to adapt to different light sources and test environments, improving the flexibility and versatility of the test.

[0021] Furthermore, when the filter is a bandpass filter, the passband center wavelength of the filter is consistent with the laser wavelength emitted by the laser, and the passband half-width of the filter is 50nm, which can ensure that only light information related to the test is received during the test, reduce light interference and scattering, and thus improve the accuracy and reliability of the test.

[0022] Furthermore, a clamping and fixing component is provided at the entrance of the laser detector, and the filter component is arranged at the entrance of the laser detector of the KPFM tester body through the clamping and fixing component. The clamping and fixing component provides a stable installation platform for the filter component, ensuring the stability and reliability of the filter component during the test process. This stability is crucial to maintaining the consistency of the filter performance, because any slight displacement or vibration may affect the filter effect, and thus affect the accuracy of the test results. At the same time, the design of the clamping and fixing component is easy to disassemble and reinstall, which allows users to easily replace the filter component to meet different test requirements or perform regular maintenance. This flexibility improves the versatility and usability of the test device; in addition, the close fit between the clamping and fixing component and the filter component helps to reduce the loss and interference of light when passing through the filter component. This tightness ensures that light can efficiently pass through the filter component and enter the laser detector, thereby improving the sensitivity and accuracy of the test.

[0023] Furthermore, the test device also includes a heat dissipation component, which is used to dissipate the heat generated by the external light source. The external light source will generate a lot of heat when working for a long time or at high power output. If the heat is not dissipated in time, it may cause the light source to overheat, affecting its performance and stability, or even causing damage. The heat dissipation component can effectively reduce the operating temperature of the light source, ensure that it operates within a safe range, and extend its service life. In addition, the temperature change of the light source may cause its spectral characteristics to change, and these changes will directly affect the accuracy of the test results. The heat dissipation component helps to ensure the consistency of the spectral characteristics of the light source during the test process by maintaining the constant temperature of the light source, thereby improving the test accuracy; in addition, overheating of the light source may cause its luminous efficiency to decrease, spectral drift and other problems, which will increase the error in the test process. The heat dissipation component reduces the test error caused by overheating of the light source by effectively dissipating heat, and improves the accuracy and repeatability of the test results.

[0024] In addition, the present invention also includes an in-situ illumination KPFM test method, which uses the above-mentioned in-situ illumination KPFM test device and includes the following steps: turning on the KPFM tester body, controlling the distance between the light outlet of the external light source and the sample stage to be 3 to 5 cm, and turning on the external light source for testing. Here, the distance between the light outlet of the external light source and the sample stage is controlled to be 3 to 5 cm, which effectively realizes the excitation of the sample to be tested and avoids the influence of the heat generated by the external light source on the sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 For lower power (~13 W / m 2 ) under different wavelengths of light, where (a, e) are the morphology and potential diagrams in the dark state, (b, f), (c, g), (d, h) are the morphology and potential diagrams under ultraviolet light, red light, and white light, respectively; Figure 2 For medium power (~130 W / m 2 ) under different wavelengths of light, where (a, d) are the morphology and potential diagrams in the dark state, (b, e), (c, f) are the morphology and potential diagrams under red light and white light illumination, respectively; Figure 3 It is a structural schematic diagram of an in-situ illumination KPFM testing device in the present invention; Figure 4 It is a schematic structural diagram of a baffle provided with through holes in the present invention; Figure 5 is the light passing band of the bandpass filter in the present invention; Figure 6 The instrument response in the dark state and under illumination in the experimental scenario where only the optical fiber light guide is set up; Figure 7 To show the effects of setting different filtering strategies under different external light sources; (ac) morphology diagram, (df) potential diagram, (a, d) dark state, (b, e) Xe light illumination plus optical fiber light guidance, (c, f) Xe light illumination plus the use of narrow bandpass filters.

[0027] Among them: 1. KPFM tester body, 2. external light source, 3. filter component, 4. through hole, 11. laser detector, 12. reflector, 13. spectroscope, 14. laser, 15. sample stage. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0032] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings: During the in-situ illumination test, different powers or wavelengths of light are used to induce the effect according to the sample to be tested. In order to explore whether the external light sources of different powers or wavelengths affect the detection results of the laser detector during the test, this embodiment was explored. Figure 1 For samples at lower power (~13 W / m 2 ) under different wavelengths of light. It can be seen from the figure that different wavelengths of light have almost no effect on the test under low power conditions. Figure 2 For samples at medium power (~130 W / m 2 ) under different wavelengths of light, the morphology and surface potential diagrams. It can be seen from the figure that the morphology and potential diagrams under light and dark conditions are almost unchanged. Therefore, it is speculated that the wavelength has a smaller impact on the test, and the power has a greater impact. So a Xe lamp light source was used to irradiate at a higher power for testing. 1714.6 W / m 2 When the Xe lamp with high power is irradiated, the light is too strong, causing the SUM value of the indicator of the needle tip reflected light intensity detected by the instrument laser detector to exceed the range, and the probe tuning in the tapping mode cannot be performed, so the test cannot be performed. Using the Xe lamp light source, the test cannot be performed under high power conditions, which proves that the higher the power, the greater the interference to the instrument test.

[0035] Based on the above problems, the present invention proposes an in-situ illumination KPFM testing device. Figure 3 As shown, the test device includes a KPFM tester body 1, which includes a laser detector 11, a reflector 12, a spectroscope 13, a laser 14 and a sample stage 15; the laser emitted by the laser 14 passes through the spectroscope 13, the sample stage 15 and the reflector 12 in sequence and enters the laser detector 11; an external light source 2 is provided near the sample stage 15, and the distance between the light outlet of the external light source 2 and the sample stage 15 is 3-5 cm; a filter component 3 is provided at the entrance of the laser detector 11. The external light source 2 is used to simulate or provide the lighting conditions of the sample to be tested in the actual working environment; the filter component 3 is used to block or attenuate the wavelength of the external light source 2 that interferes with the laser detector.

[0036] The laser emitted by the laser 14 is irradiated onto the probe micro-cantilever above the sample stage 15 through the spectroscope 13, and the laser is reflected to the reflector 12, and enters the laser detector 11 through the reflector 12 to realize the detection process; by setting an external light source 2 near the sample stage 15, the material performance under special working conditions can be tested. At the same time, by setting a filter component 3 at the entrance of the laser detector 11 of the KPFM tester body 1, the blocking or attenuation of the interference wavelength generated by the external light source 2 to the laser detector is realized. In order to meet various test requirements, the external light source 2 is a Xe lamp, a white light LED lamp, an ultraviolet lamp or a red light lamp.

[0037] In addition, when in use, first, turn on the KPFM tester body 1, control the distance between the external light source 2 and the sample to be tested to be 3~5cm, and turn on the external light source 2 for testing. When the external light source 2 is a xenon lamp, due to the large size of the xenon lamp, it is placed at a distance of 45~50cm from the sample to be tested, and then an optical fiber is provided at the light outlet of the Xe lamp, and the distance between the light outlet of the optical fiber and the sample stage 15 is 3~5cm. The optical fiber is used to guide the light emitted by the Xe lamp to the vicinity of the sample, which, on the one hand, makes the light more fully and effectively concentrated on the sample surface for sample testing, and on the other hand, avoids the light from entering the detector and affecting the test results.

[0038] At the same time, in a preferred embodiment, Figure 4 As shown, the filter assembly 3 includes a baffle or filter with a through hole 4. The diameter of the through hole 4 on the baffle is preferably 1-2 mm. The baffle is preferably copper foil or aluminum foil.

[0039] In addition, in order to prevent external light sources from entering the detector as much as possible, a sealing component is provided between the filter component 3 and the laser detector entrance of the KPFM tester body 1, so that the detection result is more accurate.

[0040] The filter in the present invention includes any one of an absorption filter, a reflection filter, a composite filter and a bandpass filter, which realizes the test requirements under different test environments. In addition, when the filter is a bandpass filter, the passband center wavelength of the filter is consistent with the laser wavelength emitted by the laser 14, and the passband half-width of the filter is 50nm. Figure 5 As shown, in one embodiment, the passband center wavelength of the filter is 650 nm.

[0041] In addition, a clamping and fixing component is provided at the entrance of the laser detector, and the filter component 3 is arranged at the entrance of the laser detector of the KPFM tester body 1 through the clamping and fixing component.

[0042] At the same time, the testing device also includes a heat dissipation component, which is used to dissipate the heat generated by the external light source 2.

[0043] In the present invention, when optical fiber is used alone for light guidance and no filter component is provided at the entrance of the laser detector, the test results will be affected to a certain extent. Figure 6 This is the test result when the optical fiber is used alone to guide the light, and no filter component is set at the entrance of the laser detector. In this test process, the optical fiber is used to guide the light of the external light source to locally illuminate the sample test area, and the external light is prevented from entering the laser four-quadrant detector as much as possible, thereby reducing interference. This method can reduce interference to a certain extent, but some light still enters the detector. When the intensity of the external light is strong, the interference will also become stronger: Figure 6 As shown, a Xe lamp is used as the light source with a large optical power. The intensity of the laser signal detected by the laser detector increases (from 4.73 to 6.75), the position deviation V changes (from -0.03 to -0.31), and the corresponding XZ cross-section curve (red and blue lines) jitters significantly.

[0044] Therefore, the present invention adds a filter component 3 on the basis of an external light source to achieve spatial filtering or spectral filtering. Here, spatial filtering refers to installing a baffle with a through hole 4 at the entrance of the laser detector. The advantage of this method is that it is easy to operate and low in cost, but the disadvantage is that the interference removal effect is not as good as spectral filtering. Because the external light source will also enter the laser detector through the small hole, the detected light intensity value will increase, the light spot will deviate from the origin position, and the morphology and potential diagram will be disturbed, but the influence of the external light source can be solved to a certain extent.

[0045] Spectral filtering refers to installing filters at the entrance of the laser detector, such as Figure 7 As shown in the figure, by adding a 650nm narrow bandpass filter in front of the laser detector and adding high-brightness Xe light illumination and dark state ratio, the laser signal intensity detected by the laser detector and the position deviation V and H values ​​will not change significantly. Figure 7 (b, e) is 1714.6 W / m 2 The Xe light was irradiated and the sample was illuminated by optical fiber. The morphology and potential map were obtained. The light power received by the sample was 811.3 W / m 2 . Figure 7 (c, f) is 1714.6 W / m 2 The morphology and potential map were obtained by adding a narrow bandpass filter in front of the laser detector. At this time, the light power received by the sample surface is still 1714.6 W / m 2 By comparing the potential of the samples under three conditions, namely, dark state, optical fiber light guidance and spectral filtering, it is found that the potential under light conditions is higher than that under dark state, and the potential increase is most obvious under spectral filtering. In addition, in order to verify the effect of the filter on the optical power, the following test was conducted: the filter was placed between the external light source and the optical power tester to test the effect of the filter on the optical power. The test results show that the power of the ultraviolet light before and after the filter is added is 20.2 W / m 2 and 1.8 W / m 2 , and the power of red light is 230.6 W / m 2 and 139.7 W / m 2 , the power of white light is 8.5 W / m 2 and 2.2 W / m 2 The power before adding the filter can be considered as the power shining on the sample, and the power after adding the filter can be considered as the power of the external light source detected by the laser detector. R Represents the power after adding the filter divided by the power before adding the filter. R The smaller the value, the better. R The results were 8.9%, 60.6% and 25.9% respectively, indicating that the spectral filtering method is most effective for ultraviolet light, followed by white light, and red light is the worst.

[0046] Therefore, direct external illumination (red light and white light) in the in-situ illumination KPFM experiment will seriously interfere with the test, and the image will have serious noise, which will prevent normal testing. The method of optical fiber light guidance, small hole spatial filtering and narrow bandpass filter filtering is used to reduce the amount of external light entering the laser detector, thereby stabilizing the test and obtaining clear and stable morphology and surface potential maps under illumination conditions. Among them, the filter method has the best effect and is worth promoting. It can provide a reference for the micro-area potential characterization of photocatalytic materials, perovskite battery materials, etc.

[0047] Based on this device, the morphology and potential diagram of the dark state and the light after filtering are normal and stable. The light source used is a high-power xenon lamp with high light intensity. Under such circumstances, the test results are very good, indicating that this spectral filtering method has great advantages.

[0048] When conducting in-situ illumination KPFM experiments, two aspects need to be considered. First, the experiment can proceed normally, and second, the light power received by the material under test can make the material generate photogenerated carriers, etc. As the power of the external light source gradually increases, stable morphology and potential diagrams can be obtained at the beginning. As the light power of the Xe lamp light source reaches 1714.6 W / m 2 When it is found that the test cannot be carried out, the power is so high that it is necessary to use the test device of the present invention to carry out the test and ensure that the light power received by the sample is as high as possible.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An in-situ illumination KPFM testing device, characterized in that: The KPFM tester comprises a KPFM tester body (1); the KPFM tester body (1) comprises a laser detector (11), a reflector (12), a beam splitter (13), a laser (14), and a sample stage (15); laser light emitted by the laser (14) passes through the beam splitter (13), the sample stage (15), and the reflector (12) in sequence and enters the laser detector (11); An external light source (2) is provided near the sample stage (15), and the distance between the light outlet of the external light source (2) and the sample stage (15) is 3 to 5 cm; A filter component (3) is provided at the entrance of the laser detector (11).

2. The in-situ illumination KPFM testing device according to claim 1, characterized in that: The external light source (2) is a Xe lamp, a white light LED lamp, an ultraviolet lamp or a red light lamp.

3. The in-situ illumination KPFM testing device according to claim 2, characterized in that: When the external light source (2) is a Xe lamp, the light outlet of the Xe lamp is provided with an optical fiber, and the distance between the light outlet of the optical fiber and the sample stage (15) is 3 to 5 cm.

4. The in-situ illumination KPFM testing device according to claim 1, characterized in that: The filter assembly (3) comprises a baffle or a filter; the baffle is provided with a through hole (4).

5. The in-situ illumination KPFM testing device according to claim 4, characterized in that: The diameter of the through hole (4) on the baffle is 1-2 mm.

6. The in-situ illumination KPFM testing device according to claim 1, characterized in that: The optical filter includes any one of an absorption filter, a reflection filter, a composite filter and a bandpass filter.

7. The in-situ illumination KPFM testing device according to claim 6, characterized in that: When the optical filter is a bandpass filter, the passband center wavelength of the optical filter is consistent with the wavelength of the laser emitted by the laser (14), and the passband half-width of the optical filter is 50 nm.

8. The in-situ illumination KPFM testing device according to claim 1, characterized in that: A clamping and fixing component is provided at the entrance of the laser detector, and the filter component (3) is arranged at the entrance of the laser detector of the KPFM tester body (1) through the clamping and fixing component.

9. The in-situ illumination KPFM testing device according to claim 1, characterized in that: The testing device also includes a heat dissipation component, which is used to dissipate heat generated by the external light source (2).

10. An in-situ illumination KPFM test method, characterized in that: The in-situ illumination KPFM testing device according to any one of claims 1 to 9 is used, and comprises the following steps: The KPFM tester body (1) is turned on, the distance between the light outlet of the external light source (2) and the sample stage (15) is controlled to be 3 to 5 cm, and the external light source (2) is turned on for testing.

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