Polarized photoelectric detection device based on vacancy defect two-dimensional material and preparation method thereof
By introducing vacancy defects into two-dimensional materials and constructing a bias electric field with electrodes, a high-performance polarization photoelectric detection device was fabricated, which solved the problem of low anisotropy in the prior art and achieved high sensitivity and high temperature stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGXI NORMAL UNIV
- Filing Date
- 2022-12-20
- Publication Date
- 2026-07-21
AI Technical Summary
Existing polarization photoelectric detection devices based on low-dimensional materials suffer from low anisotropy, which limits their performance and applications.
A polarization photoelectric detection device based on a two-dimensional material with vacancy defects was prepared by introducing atomic vacancy defects into the two-dimensional material, forming a bias electric field with the first and second electrodes, and constructing a central irradiation region to absorb light signals.
It significantly improves the polarization sensitivity and high-temperature stability of the polarization photodetector, increases the maximum extinction ratio by an order of magnitude, and doubles the maximum photoresponse in the initial state, thereby enhancing photoelectric performance.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polarization photoelectric detection technology, specifically to a polarization photoelectric detection device based on two-dimensional materials with vacancy defects and its preparation method. Background Technology
[0002] Photodetectors can directly convert photoelectric signals to achieve light detection. Among various photodetectors, polarization photodetectors can accurately identify the polarization information of light, improving the accuracy and precision of light detection. They have very important application value in fields such as remote sensing imaging, environmental monitoring, medical testing, and military equipment.
[0003] Currently, polarization detection is mainly based on the polarization sensitivity of one-dimensional nanomaterials. However, the high processing difficulty and complex alignment of nanochannels of these materials limit their application in the field of polarization detection. With the further miniaturization and integration of information devices, polarization detectors made of novel low-dimensional materials can directly sense polarized light by utilizing the intrinsic anisotropy of the material. Many two-dimensional / one-dimensional semiconductor materials, such as black phosphorus [Nature Nanotechnology 10, 707 (2015)], ReS2, GaTe, GeSe, GeAs, and ZrS3, mentioned by Wei Zhongming et al. in Acta Physica Sinica, 68, 163201 (2019), all have strong intrinsic in-plane anisotropy and can be used for high-performance polarization photodetectors. Different structural types of polarization photodetectors designed with such low-dimensional semiconductor materials have covered multiple bands, including ultraviolet, visible, and infrared. Compared with traditional polarization photodetectors that integrate lenses and detection systems, in-plane anisotropic polarization photodetectors based on two-dimensional semiconductors have attracted extensive research in recent years due to their small size, high performance, and low power consumption. However, research results show that they still have the problem of relatively low anisotropy.
[0004] In summary, in view of the problems existing in the above-mentioned technologies, there is an urgent need for a new high-performance polarization light detection device based on low-dimensional materials. Summary of the Invention
[0005] Based on the above description, the present invention provides a polarization photoelectric detection device based on two-dimensional materials with vacancy defects and its preparation method, so as to solve the technical problem of low anisotropy in existing polarization photoelectric detection devices.
[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:
[0007] In a first aspect, the present invention provides a polarization photoelectric detection device based on a two-dimensional material with vacancy defects, comprising: a two-dimensional material, a first electrode, and a second electrode;
[0008] The two-dimensional material has vacancy defects to form a central irradiation region, which is used to absorb light signals;
[0009] The first electrode and the second electrode are arranged opposite each other on both sides of the central irradiation area. The first electrode and the second electrode are used to apply a bias voltage to form a bias electric field.
[0010] Based on the above technical solution, the present invention can be further improved as follows.
[0011] Furthermore, the two-dimensional material is a TlPt2S3 thin film.
[0012] Furthermore, the TlPt2S3 film is a single-layer film.
[0013] Furthermore, both the first electrode and the second electrode are noble metal electrodes.
[0014] Furthermore, the thickness of both the first electrode and the second electrode is 50–60 nm.
[0015] Furthermore, the polarization photoelectric detection device also includes a substrate;
[0016] The two-dimensional material, the first electrode, and the second electrode are all disposed on the substrate and are arranged on the same side of the substrate.
[0017] Furthermore, the substrate comprises a Si substrate and a SiO2 layer;
[0018] The SiO2 layer is disposed on the Si substrate to form a SiO2 / Si substrate.
[0019] In a second aspect, the present invention also provides a method for fabricating a polarization photoelectric detection device based on a vacancy defect two-dimensional material as described in any one of the first aspects, comprising:
[0020] Step 1: Peel off a single-layer thin film of two-dimensional material and use plasma radiation to create atomic vacancy defects in the two-dimensional material;
[0021] Step 2: Assemble the two-dimensional material with the first electrode and the second electrode to prepare a polarization photodetector with the structure of electrode-two-dimensional material thin film-electrode.
[0022] Based on the above technical solution, the present invention can be further improved as follows.
[0023] Furthermore, in step 2, assembling the two-dimensional material with the first electrode and the second electrode specifically includes:
[0024] Two-dimensional material thin films were loaded onto a SiO2 / Si substrate;
[0025] The two-dimensional material film is spin-etched using a photolithography machine to obtain a first groove and a second groove that are adapted to the shapes of the first electrode and the second electrode;
[0026] The first electrode and the second electrode are vapor-deposited at the first groove and the second groove, and then dried to obtain a polarization photoelectric detection device with an electrode-two-dimensional material thin film-electrode structure.
[0027] Furthermore, before loading the two-dimensional material thin film onto the SiO2 / Si substrate, the following steps are also included:
[0028] The SiO2 / Si substrate was prepared by ultrasonically cleaning it in acetone, anhydrous ethanol and deionized water for 2-5 minutes, drying it, and then treating it with ozone for 15-30 minutes.
[0029] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:
[0030] The polarization photodetector based on vacancy-defect two-dimensional materials provided by this invention uses two-dimensional materials with atomic vacancy defects. On the one hand, the maximum extinction ratio obtained by atomic defects is an order of magnitude higher than that of conventional materials in the prior art, effectively solving the problem of low anisotropy in current polarization photodetectors and exhibiting good polarization sensitivity. On the other hand, the standard deviation of the potential energy change of the two-dimensional material in the vacancy defect state is between 0 and 0.1 in the temperature range of 300-500 K, giving the polarization photodetector good high-temperature stability. In addition, the maximum light response under the atomic vacancy defects of the two-dimensional material can reach more than twice the maximum light response of the initial state, effectively improving the photoelectric performance of the polarization photodetector. Attached Figure Description
[0031] Figure 1 This is a schematic diagram of the structure of a polarization photoelectric detection device based on two-dimensional materials with vacancy defects provided in an embodiment of the present invention;
[0032] Figure 2 A schematic diagram illustrating the fabrication method of the polarization photoelectric detection device based on two-dimensional materials with vacancy defects provided in this embodiment of the invention;
[0033] Figure 3 This is a schematic diagram illustrating the band gap changes of the polarization photoelectric detection device provided in the embodiments of the present invention in the initial state and under different atomic vacancy defect states; wherein, Figure 3 (a) is the initial state of the TlPt2S3 thin film without defects. Figure 3(b) 8% thallium element defects in TlPt2S3 thin films Figure 3 (c) 8% platinum element defects in TlPt2S3 thin films; Figure 3 (d) represents 8% sulfur element defects in the TlPt2S3 thin film;
[0034] Figure 4 The diagrams showing the relationship between photocurrent and incident polarization angle of the polarization photodetector provided in this embodiment of the invention in the initial state and under different atomic vacancy defect states are shown. Figure 4 (a) is the initial state of the TlPt2S3 thin film without defects. Figure 4 (b) 8% thallium element defects in TlPt2S3 thin films Figure 4 (c) 8% platinum element defects in TlPt2S3 thin films; Figure 4 (d) represents 8% sulfur element defects in the TlPt2S3 thin film;
[0035] Figure 5 A schematic diagram of the maximum photocurrent (photoresponse) of the polarization photodetector provided in the embodiments of the present invention in the initial state and under different atomic vacancy defect states;
[0036] Figure 6 A schematic diagram showing the standard deviation and mean standard deviation of thin film type and potential energy change under temperature variation of 300-500K for the polarization photoelectric detection device provided in the embodiment of the present invention;
[0037] Figure 7 A schematic diagram illustrating the anisotropic current ratio of the polarization photoelectric detection device provided in this embodiment of the invention in the initial state and under different atomic vacancy defect states; wherein, Figure 7 (a) is a schematic diagram of the anisotropic current ratio in the initial state of a defect-free TlPt2S3 thin film. Figure 7 (b) is a schematic diagram of the anisotropic current ratio of 8% thallium element defects in TlPt2S3 thin films. Figure 7 (c) is a schematic diagram of the anisotropic current ratio of defects in 8% platinum element in TlPt2S3 thin film. Figure 7 (d) is a schematic diagram of the anisotropic current ratio of 8% sulfur element defects in TlPt2S3 thin film.
[0038] The attached diagram lists the components represented by each number as follows:
[0039] 1. Two-dimensional material; 2. First electrode; 3. Second electrode; 4. Substrate. Detailed Implementation
[0040] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.
[0041] The following is in conjunction with the appendix Figures 1 to 7 The embodiments will be described in further detail below to illustrate the implementation of the present invention. The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of the present invention.
[0042] Firstly, such as Figure 1 As shown, this embodiment of the invention provides a polarization photoelectric detection device based on a two-dimensional material with vacancy defects, comprising: a two-dimensional material, a first electrode, and a second electrode.
[0043] Two-dimensional materials have vacancy defects to form a central irradiation region, which is used to absorb light signals.
[0044] The first and second electrodes are arranged opposite each other on both sides of the central irradiation area. The first and second electrodes are used to apply a bias voltage to form a bias electric field.
[0045] Specifically, the polarization photoelectric detection device based on two-dimensional materials with atomic vacancy defects provided in this embodiment of the invention is fabricated using two-dimensional materials with atomic vacancy defects. Therefore, it has the following three advantages compared to the prior art:
[0046] Firstly, the maximum extinction ratio obtained by atomic defects is an order of magnitude higher than that of conventional materials in the existing technology, which effectively solves the problem of low anisotropy of polarization photoelectric detection devices at present and has good polarization sensitivity.
[0047] Secondly, the standard deviation of the potential energy change of the two-dimensional material in the vacancy defect state between 300 and 500 K is between 0 and 0.1, which makes the polarization photoelectric detection device have good high-temperature stability.
[0048] Thirdly, the maximum photoresponse under atomic vacancy defects in two-dimensional materials can reach more than twice the maximum photoresponse in the initial state, effectively improving the photoelectric performance of the polarization photoelectric detection device.
[0049] In an optional embodiment, the two-dimensional material is a TlPt2S3 (platinum thallium sulfide) thin film.
[0050] Furthermore, the TlPt2S3 film is a single-layer film, and to avoid affecting its performance, the TlPt2S3 film is clean.
[0051] In optional embodiments, both the first electrode and the second electrode are precious metal electrodes. In specific examples, they can be gold, silver, or platinum, etc. The specific type of electrode is not limited and can be selected according to actual needs.
[0052] In an optional embodiment, the thickness of both the first electrode and the second electrode is 50-60 nm, and the specific thickness is not limited and can be set according to the actual situation.
[0053] In optional embodiments, such as Figure 1 As shown, the polarization photoelectric detection device also includes a substrate.
[0054] The two-dimensional material, the first electrode, and the second electrode are all disposed on the substrate and are located on the same side of the substrate.
[0055] The substrate includes a Si (silicon) substrate and a SiO2 (silicon dioxide) layer, with the SiO2 layer disposed on the Si substrate to form a SiO2 / Si substrate.
[0056] Secondly, such as Figure 2 As shown, embodiments of the present invention also provide a method for fabricating a polarization photoelectric detection device based on a vacancy defect two-dimensional material as described in any of the first aspects, comprising:
[0057] Step S1: Peel off a single-layer thin film of two-dimensional material and use plasma radiation to create atomic vacancy defects in the two-dimensional material;
[0058] Step S2: Assemble the two-dimensional material with the first electrode and the second electrode to prepare a polarization photodetector with the structure of electrode-two-dimensional material thin film-electrode.
[0059] In an optional embodiment, step S2, assembling the two-dimensional material with the first electrode and the second electrode, specifically includes:
[0060] Two-dimensional material thin films were loaded onto a SiO2 / Si substrate;
[0061] A two-dimensional material thin film is spin-etched using a photolithography machine to obtain a first groove and a second groove that are adapted to the shape of the first electrode and the second electrode;
[0062] A first electrode and a second electrode are vapor-deposited at the first groove and the second groove, and then dried to obtain a polarization photoelectric detection device with an electrode-two-dimensional material thin film-electrode structure.
[0063] The process includes, before loading the two-dimensional material thin film onto the SiO2 / Si substrate, the following steps:
[0064] SiO2 / Si was sequentially ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 2-5 min each, dried and then treated with ozone for 15-30 min to prepare a SiO2 / Si substrate.
[0065] Specifically, the preparation method provided in the embodiments of the present invention will be further described using TlPt2S3 as a two-dimensional material:
[0066] Step 1: Place SiO2 / Si in acetone, anhydrous ethanol and deionized water in sequence for ultrasonic cleaning for 2-5 min, dry with N2 gas gun, and then perform ozone treatment for 15-30 min to obtain the treated SiO2 / Si substrate.
[0067] Step 2: Mechanically peel off the TlPt2S3 film using single-crystal tape; under an optical microscope, select single-layer TlPt2S3 films with clean surfaces from the peeled samples, and then use plasma radiation to create atomic vacancy defects in the films;
[0068] Step 3: Apply PDMS (polydimethylsiloxane) to a glass slide, evenly coat a PVA (polyvinyl alcohol) layer, heat and dry it, then bring the PVA into contact with TlPt2S3, and then heat to 90-95℃. After the PVA melts, stop heating and cool to room temperature. Then lift the glass slide. The TlPt2S3 film will detach from the SiO2 / Si substrate along with the glass slide / PDMS / PVA, thus obtaining the glass slide / PDMS / PVA / TlPt2S3 film.
[0069] Step 4: Place the SiO2 / Si substrate with the TlPt2S3 thin film in a dimethyl sulfoxide solution and heat it at a temperature of 50-60°C. After the PVA is completely dissolved, remove the substrate and dry it with an N2 gas gun to obtain the TlPt2S3 thin film.
[0070] Step 5: Spin-coat the prepared TIPt2S3 thin film with photoresist, etch the electrode shape using a maskless photolithography machine, deposit the electrode using an electron beam evaporation machine, soak it in acetone at room temperature, and dry it with an N2 gas gun to obtain a polarization-sensitive photodetector, which is the electrode-TlPt2S3 thin film-electrode.
[0071] Furthermore, to further verify the technical effectiveness of the polarization photoelectric detection device based on vacancy-defect two-dimensional materials provided in the embodiments of the present invention, taking TIPt2S3 as an example, its photoelectric performance is introduced as follows:
[0072] A bias voltage of 0.2V was applied to the first electrode and the second electrode. Different wavelengths of incident light, ranging from 440-775nm, were irradiated onto TIPt2S3 films with different atomic vacancy defects at different incident polarization angles, from 0 to 180 degrees. Changes in photocurrent, photoresponse, and extinction ratio were observed and calculated, and the measurements were plotted. The thermal stability of the TIPt2S3 films with atomic vacancy defects was then observed by adjusting the temperature. The results are as follows: Figures 3 to 7 As shown.
[0073] Figure 3 (ad) is a schematic diagram illustrating the band gap changes of a polarization photodetector for a TlPt2S3 thin film in the initial state and under different atomic 8% vacancy defect states. Analysis of the attached diagram reveals that the band gap can be modulated by controlling the vacancy defects in Tl, Pt, and S atoms, changing the band gap from the initial 1.63 eV to 0 eV, 0.28 eV, and 0.45 eV, respectively. More specifically, the 0.08Pt- vacancy has a direct band gap, with the conduction band minimum (CBM) and valence band maximum (VBM) located at point G, while the 0.08S- vacancy has an indirect band gap, with the conduction band minimum and valence band maximum located at point K and along the GM direction, respectively. Furthermore, by generating the 0.08Tl- vacancy, the valence band maximum crosses the Fermi level, indicating that it possesses half-metallic characteristics. Therefore, vacancy defect manipulation can narrow the band gap, making it easier for electrons to transition from the valence band to the conduction band, increasing the transition probability, and thus generating a larger photocurrent, making it more suitable for optoelectronic devices.
[0074] Figure 4 (ad) shows the relationship between photocurrent and polarization angle for initial TlPt2S3 and different defect systems in the wavelength range of 440nm-775nm. The selected incident polarization angle is from 0 to 180 degrees. It can be seen that photocurrent is generated in the selected wavelength range, and the image approximately follows the sin and cos function mode as the incident polarization angle changes. Furthermore, the photocurrent of TlPt2S3 in the defect state increases by two orders of magnitude compared to the initial TlPt2S3, making it easier to measure and detect. Therefore, the polarization photodetector based on the vacancy defect TlPt2S3 thin film can be well used for polarization detection.
[0075] Figure 5The graphs showing the relationship between incident light wavelength and maximum photocurrent (photoresponse) of a polarized photodetector on a TlPt2S3 thin film in the initial state and under different atomic 8% vacancy defect states are plotted under a bias voltage of 0.2V, incident light wavelengths ranging from 440nm to 775nm, and incident polarization angles from 0 to 180 degrees. It can be seen that at incident wavelengths exceeding 689nm, the maximum photocurrent (photoresponse) value in the initial state is less than that in the TlPt2S3 thin film with Pt and S atomic defects, while the opposite is true at other wavelengths. Compared to the maximum photocurrent (photoresponse) value of Tl atomic defects, the maximum photocurrent (photoresponse) value in the initial state is less than that in the Tl atomic defect state in all wavelength ranges except from 517nm to 564nm.
[0076] Based on the above Figure 5 Analysis shows that by appropriately adjusting atomic defects and incident wavelength, the optical response of the polarization detector can be effectively increased. It should be noted that the magnitude of the maximum photocurrent represents the magnitude of the optical response.
[0077] Figure 6 The diagram shows the standard deviation and average standard deviation of the potential energy change for different film types under temperature variations of 300-500 K. The total energy of these systems oscillates slightly over a long period without decaying, and the standard deviation of their potential energy changes is between 0 and 0.1, indicating that they have good thermal stability. Among them, the average standard deviation of the potential energy for 8% Tl vacancies and 8% S vacancies is relatively small, indicating that appropriate vacancy defects can improve the high-temperature stability of monolayer TlPt2S3.
[0078] Figure 7 (ad) is a graph showing the relationship between incident light and extinction ratio in the initial state and under different atomic 8% vacancy defect states, with a bias voltage of 0.2V, an incident light wavelength in the range of 440nm to 775nm, and an incident polarization angle from 0 to 180 degrees. Figure 7 (a) is a schematic diagram of the incident light wavelength and extinction ratio of the polarization photodetector of TlPt2S3 thin film in the initial state. The extinction ratio reaches the maximum value of 1.3 when the incident wavelength is 590nm. Figure 7 (b) is a schematic diagram of the incident light wavelength and extinction ratio of the polarization photodetector of TlPt2S3 thin film in the 8% Tl atomic defect state. When the incident wavelength is 689nm, the extinction ratio reaches the maximum value of 2.7, which is twice that in the initial state. Figure 7 (c) is a schematic diagram of the incident light wavelength and extinction ratio of the polarization photodetector of TlPt2S3 thin film in the 8% Pt atomic defect state. The extinction ratio reaches a maximum of 8.2 when the incident wavelength is 729nm, which is 6.3 times that in the initial state. Figure 7(d) is a schematic diagram of the incident light wavelength and extinction ratio of the polarization photodetector of TlPt2S3 thin film in the 8% S atomic defect state. The extinction ratio reaches a maximum of 16.6 when the incident wavelength is 517nm, which is 12.7 times that in the initial state.
[0079] Furthermore, compared to the maximum extinction ratios of graphene (8.7), lead sulfide (2.38), and germanium sulfide (2.1), the maximum extinction ratio of the TIPt2S3 film with atomic vacancy defects shows an increasing trend, increasing by up to an order of magnitude. This can effectively solve the problem of low dichroism ratio in polarized photodetectors.
[0080] Extinction ratio Sensitivity
[0081] Sensitivity was processed to obtain
[0082] The sensitivity of a polarization photodetector is related to the extinction ratio; the higher the extinction ratio, the higher the sensitivity, and vice versa. Figure 7 Extinction ratio analysis showed that the sensitivity of TlPt2S3 atomic vacancy defect state was greatly enhanced compared with the initial state, and its sensitivity was also significantly improved compared with polarization detectors based on other materials.
[0083] Based on the above analysis, the polarization photodetector designed using a TlIPt2S3 thin film with appropriate atomic vacancy defects in the embodiments of the present invention has high performance and high polarization sensitivity.
[0084] In the description of this specification, references to terms such as "specific example" or "some examples" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The specific features, structures, materials, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.
[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A polarization photoelectric detection device based on two-dimensional materials with vacancy defects, characterized in that, include: Two-dimensional material, first electrode and second electrode; The two-dimensional material has vacancy defects to form a central irradiation region, which is used to absorb light signals; The first electrode and the second electrode are arranged opposite each other on both sides of the central irradiation area. The first electrode and the second electrode are used to apply a bias voltage to form a bias electric field. The two-dimensional material is a TlPt2S3 thin film. The TlPt2S3 thin film is a single-layer thin film.
2. The polarization photoelectric detection device based on two-dimensional materials with vacancy defects according to claim 1, characterized in that, Both the first electrode and the second electrode are noble metal electrodes.
3. The polarization photoelectric detection device based on two-dimensional materials with vacancy defects according to claim 2, characterized in that, The thickness of both the first electrode and the second electrode is 50~60 nm.
4. The polarization photoelectric detection device based on two-dimensional materials with vacancy defects according to claim 1, characterized in that, The polarization photoelectric detection device also includes a substrate; The two-dimensional material, the first electrode, and the second electrode are all disposed on the substrate and are arranged on the same side of the substrate.
5. The polarization photoelectric detection device based on two-dimensional materials with vacancy defects according to claim 4, characterized in that, The substrate comprises a Si substrate and a SiO2 layer; The SiO2 layer is disposed on the Si substrate to form a SiO2 / Si substrate.
6. A method for fabricating a polarization photoelectric detection device based on a vacancy defect two-dimensional material as described in any one of claims 1 to 5, characterized in that, include: Step 1: Peel off a single-layer thin film of two-dimensional material and use plasma radiation to create atomic vacancy defects in the two-dimensional material; Step 2: Assemble the two-dimensional material with the first electrode and the second electrode to prepare a polarization photodetector with the structure of electrode-two-dimensional material thin film-electrode.
7. The preparation method according to claim 6, characterized in that, In step 2, assembling the two-dimensional material with the first electrode and the second electrode specifically includes: Two-dimensional material thin films were loaded onto a SiO2 / Si substrate; The two-dimensional material film is spin-etched using a photolithography machine to obtain a first groove and a second groove that are adapted to the shapes of the first electrode and the second electrode; The first electrode and the second electrode are vapor-deposited at the first groove and the second groove, and then dried to obtain a polarization photoelectric detection device with an electrode-two-dimensional material thin film-electrode structure.
8. The preparation method according to claim 7, characterized in that, Before loading the two-dimensional material thin film onto the SiO2 / Si substrate, the following steps are also included: The SiO2 / Si substrate was prepared by ultrasonically cleaning it in acetone, anhydrous ethanol and deionized water for 2-5 min respectively, drying it, and then treating it with ozone for 15-30 min.