High-performance nitrogen vacancy color center diamond material under protection of yttrium oxide as well as preparation method and application of high-performance nitrogen vacancy color center diamond material

Abstract

The invention provides a high-performance nitrogen vacancy color center diamond material under yttrium oxide protection and a preparation method and application thereof, and belongs to the technical field of quantum materials. The preparation method comprises the following steps: firstly carrying out electron irradiation and cleaning on a diamond substrate, then processing by adopting nitrogen plasma, then depositing an yttrium oxide coating, and annealing the diamond substrate deposited with the yttrium oxide coating under a vacuum condition to obtain the high-performance nitrogen vacancy color center diamond material. According to the method, the diamond is treated through the nitrogen plasma, so that the displacement nitrogen concentration in the diamond can be increased, and the NV-color center concentration can be increased in the subsequent annealing treatment process; meanwhile, the yttrium oxide coating is deposited on the diamond substrate, so that defects on the surface of the diamond can be reduced, the NV-color center concentration is increased, and the prepared diamond material has excellent corrosion resistance. The diamond material prepared by the preparation method can be used for preparing quantum sensors used under extreme conditions.

Description

Technical Field

[0001] This invention belongs to the field of quantum materials technology, specifically relating to a high-performance nitrogen-vacancy color center diamond material protected by yttrium oxide, its preparation method, and its application. Background Art

[0002] Generally speaking, any technology that realizes or enhances the sensitive measurement of physical quantities through quantum systems, quantum properties, or quantum phenomena can be called quantum sensing. Typical physical systems for realizing quantum sensing include superconducting quantum interference devices, atomic systems (including cold atoms, hot atoms, and Rydberg atoms), ions, spins, photons, and optical-mechanical composite systems. Diamond nitrogen vacancies (NV) color centers possess electrically neutral NVs. 0 and electronegative NV - Two forms. NV - Color centers, as solid-state quantum light sources, possess remarkable characteristics such as millisecond-level spin coherence time at room temperature, efficient initialization and readout of spin states optically, and microwave manipulation, demonstrating broad application prospects in quantum technology research fields such as single-photon sources, micromagnetic detection, and bioimaging. However, despite NV... - Color centers possess various superior properties, but are affected by NV. - The limitation of low color core concentration, NV - The practical applications of color-centered diamond are severely limited. Furthermore, extreme application environments also restrict NV. - Applications of color-centered diamond. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method for preparing high-performance nitrogen-vacancy center (NV) diamond materials under yttrium oxide protection. This method improves the NV content of diamond. - The concentration of color centers; at the same time, the diamond material prepared can meet the needs of use in extreme environments.

[0004] Specifically, the present invention adopts the following technical solution to achieve the above objectives: A method for preparing a high-performance nitrogen-vacancy color center diamond material includes the following steps: S1. The diamond substrate is subjected to electron irradiation treatment, and then the diamond substrate is cleaned; S2. The diamond substrate is subjected to nitrogen plasma treatment, and a yttrium oxide coating is deposited on the surface of the diamond substrate by magnetron sputtering. Specifically, the following steps are included: the cleaned diamond substrate from step S1 is placed in a magnetron sputtering coating machine, a vacuum is drawn, and after the vacuum level in the magnetron sputtering coating machine reaches the baseline vacuum, nitrogen gas is introduced to perform nitrogen plasma treatment on the diamond substrate. After the treatment is completed, the diamond substrate is heated, an inert gas is introduced, and a yttrium oxide target is used for pre-sputtering. After the pre-sputtering is completed, the pressure in the magnetron sputtering coating machine is reduced for the formal sputtering. S3. Anneal the diamond substrate with yttrium oxide coating under vacuum conditions.

[0005] In a preferred embodiment, the method for cleaning the diamond substrate in step S1 includes the following steps: ultrasonically cleaning the diamond substrate in acetone, alcohol and deionized water in sequence, using an ultrasonic power of 160~200W for 10~20 minutes each time; after ultrasonication, drying it with nitrogen gas.

[0006] In the preferred embodiment, the power of the electron gun used for electron irradiation in step S1 is 8~10kW, and the irradiation time is 120min.

[0007] In a preferred embodiment, the nitrogen plasma treatment power of the diamond substrate in step S2 is 200~300W, the gas pressure is 2Pa, the gas flow rate is 160sccm, and the treatment time is 120~240min.

[0008] In a preferred embodiment, the diamond substrate is heated to 250°C to 350°C in step S2.

[0009] In a preferred embodiment, the background vacuum is ≤10. -4 Pa.

[0010] In a preferred embodiment, the inert gas is Ar, and the gas flow rate is 40~80 sccm.

[0011] In a preferred embodiment, the pre-sputtering conditions are: sputtering for 3 to 8 minutes at a sputtering power of 160 to 200 W when the pressure is ≤2 Pa.

[0012] In a preferred embodiment, the conditions for formal sputtering are: sputtering for 200-400 minutes at a pressure of 0.2-0.6 Pa and a sputtering power of 160-200 W.

[0013] In the preferred embodiment, the annealing temperature in step S3 is 300~900℃, and the holding time is 1~3h.

[0014] In a further preferred embodiment, the annealing temperature in step S3 is 900°C.

[0015] In the preferred embodiment, the heating rate in step S3 is 8~10℃ / min.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) The nitrogen plasma treatment described in this invention utilizes nitrogen atoms with high activity and energy. When treating a diamond substrate, these high-energy nitrogen atoms can more easily enter the diamond lattice, increasing the concentration of substituted nitrogen in the diamond. This leads to an increase in the concentration of NV centers during subsequent annealing and other treatments, enabling the prepared diamond material to play a better role in applications such as quantum communication, quantum computing, and quantum sensing. (NV center concentration of diamond) - Increasing the concentration of color centers increases the number of quantum states that can be excited per unit volume, which can significantly improve the sensitivity of quantum devices; it can also reduce background noise, making it suitable for high-precision spectral detection (such as single-photon sources) and improving testing accuracy.

[0017] (2) In this invention, by depositing a yttrium oxide coating on a diamond substrate, surface carbonization and oxidation of the diamond during high-temperature annealing are avoided, effectively isolating the diamond surface from direct contact with the external environment, reducing the generation of surface defects, and improving NV. - Color center concentration. Therefore, the yttrium oxide coating can protect the nitrogen vacancy color center diamond from rapid corrosion in extreme environments (such as corrosive gases), thus maintaining stable performance and not affecting its use.

[0018] (3) The vacuum annealing process in this invention causes the atoms or molecules of the yttrium oxide coating to rearrange through diffusion, reducing the porosity and defects inside the coating and forming a denser microstructure. This densification significantly enhances the physical barrier effect of the coating and reduces the permeability of corrosive media (such as acidic gases). Simultaneously, the yttrium oxide coating covers the diamond surface during annealing, preventing carbon atom oxidation or contamination at high temperatures (such as adsorption of impurity gases), thus protecting the NV (non-toxic) surface. - The formation of color centers provides a clean environment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the high-performance nitrogen-vacancy color center diamond material prepared in Example 1 of the present invention; Figure 2 The image shows the XRD pattern of the high-performance nitrogen-vacancy color center diamond material prepared in Example 1 of this invention. Figure 3 This is a magnified image under a microscope of the high-performance nitrogen-vacancy color center diamond material prepared in Example 1 of the present invention; Figure 4This is a comparison chart showing the corrosion rates of diamond materials prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention in a corrosive atmosphere. Figure 5 The PL spectra of the diamond substrate used in this invention and the diamond material with nitrogen vacancy color centers and yttrium oxide coating prepared in Comparative Example 3 before and after annealing are shown. Figure 6 The PL spectra of the high-performance nitrogen-vacancy color center diamond material prepared in Example 1 of this invention before and after annealing.

[0020] In the figure: 1. Diamond substrate; 2. Yttrium oxide coating. Detailed Implementation

[0021] The following description, in conjunction with embodiments, clearly and completely describes the technical solutions of this application, so that those skilled in the art can fully understand this application. Obviously, the described embodiments are merely some preferred embodiments of this application, and not all embodiments. Any equivalent modifications or substitutions made by those skilled in the art to the following embodiments without creative effort are within the protection scope of this application.

[0022] The yttrium oxide (Y2O3) target material used in the following examples was purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd., with a purity of 99.99%, a target diameter of 60mm, a thickness of 3mm, and a 2mm copper backing plate.

[0023] A specific embodiment of the present invention provides a method for preparing a high-performance nitrogen-vacancy color center diamond material, comprising the following steps: S1. Electron irradiation treatment and cleaning of the diamond substrate. A diamond substrate (oriented as (111)) was placed in an electron beam evaporation coating apparatus and irradiated for 120 minutes using an electron gun with a power of 8~10kW. After that, it was ultrasonicated in acetone, alcohol and deionized water in sequence, each time using an ultrasonic power of 160W~200W for 10~20 minutes. After ultrasonication, it was dried with nitrogen gas.

[0024] S2, nitrogen plasma treatment and preparation of yttrium oxide coating The cleaned diamond substrate is placed inside the magnetron sputtering coating machine. The molecular pump and mechanical pump are turned on, and the vacuum level inside the chamber is ≤10. -4After the initial pressure (Pa), nitrogen gas is introduced, and the chamber pressure is adjusted to 2 Pa, the gas flow rate to 160 sccm, and the power to 200-300 W. The diamond substrate is then treated for 120-240 minutes. After treatment, the diamond substrate is heated to 250-350°C. Inert gas is introduced at a flow rate of 40-80 sccm, and yttrium oxide (Y₂O₃) target is pre-sputtered for 3-8 minutes at a pressure ≤2 Pa and a sputtering power of 160-200 W. After pre-sputtering, the baffle is opened, and the chamber pressure is adjusted to 0.2 Pa-0.6 Pa. Sputtering continues at a sputtering power of 160-200 W for 200-400 minutes.

[0025] S3, Vacuum Annealing After sputtering, the diamond substrate coated with yttrium oxide was removed, placed in a tube furnace, evacuated to -0.08 MPa, heated to 300-900°C at a heating rate of 8-10°C / min, held for 1-3 hours, and then allowed to cool naturally to room temperature to obtain a diamond material with nitrogen vacancy color centers and yttrium oxide coating.

[0026] Example 1 A method for preparing a high-performance nitrogen-vacancy color center diamond material includes the following steps: S1. Electron irradiation treatment and cleaning of the diamond substrate. A diamond substrate (oriented as (111)) was placed in an electron beam evaporation coating apparatus and irradiated with a 10kW electron gun for 120 minutes. After that, the diamond substrate was ultrasonically treated in acetone, alcohol and deionized water in sequence, each time with an ultrasonic power of 180W for 10 minutes. After ultrasonication, it was dried with nitrogen gas.

[0027] S2, nitrogen plasma treatment and preparation of yttrium oxide coating The cleaned diamond substrate is placed inside the magnetron sputtering coating machine. The molecular pump and mechanical pump are turned on, and the vacuum level inside the chamber is ≤10. -4 After passing through the chamber, nitrogen gas was introduced, and the chamber pressure was adjusted to 2 Pa. The gas flow rate was set to 160 sccm, and the power was adjusted to 250 W. The diamond substrate was treated for 200 min. After treatment, the diamond substrate was heated to 300 °C. Argon gas (Ar) was introduced at a flow rate of 60 sccm, and yttrium oxide (Y₂O₃) target was used for pre-sputtering at a sputtering power of 180 W for 5 min. After pre-sputtering, the baffle was opened, and the chamber pressure was adjusted to 0.4 Pa. Sputtering continued at a sputtering power of 180 W for 240 min.

[0028] S3, Vacuum Annealing After sputtering, the diamond substrate coated with yttrium oxide was removed and placed in a tube furnace. The furnace was evacuated to -0.08 MPa and heated to 900 °C at a rate of 9 °C / min, held at that temperature for 2 hours, and then allowed to cool naturally to room temperature, yielding a diamond material with nitrogen vacancy centers and a yttrium oxide coating. The structure of this diamond material is as follows: Figure 1 As shown, a yttrium oxide coating 2 is deposited on a diamond substrate 1. Figure 2 This is the X-ray diffraction (XRD) pattern of the diamond material prepared in this embodiment. From... Figure 2 As can be seen above, this embodiment successfully prepared a yttrium oxide coating on a diamond substrate. The orientation of the yttrium oxide is (111), (200), (220), (311) crystal planes. Compared with the Y2O3 standard PDF (powder diffraction file) card, it was found that the yttrium oxide coating has a cubic phase structure. Figure 3 The image shows the diamond material prepared in this embodiment magnified 500 times under a microscope. As can be seen from the image, the diamond grains are densely arranged, well grown, and exhibit a typical (111) orientation.

[0029] Example 2 The method for preparing a high-performance nitrogen-vacancy color center diamond material in this embodiment is basically the same as that in Example 1, except that the annealing temperature in step S3 is 600℃.

[0030] Example 3 The method for preparing a high-performance nitrogen-vacancy color center diamond material in this embodiment is basically the same as that in Example 1, except that the annealing temperature in step S3 is 300℃.

[0031] Example 4 A method for preparing a high-performance nitrogen-vacancy color center diamond material includes the following steps: S1. Electron irradiation treatment and cleaning of the diamond substrate. A diamond substrate (oriented (111)) was placed in an electron beam evaporation coating apparatus and irradiated with a 10kW electron gun for 120 minutes. After that, the diamond substrate was ultrasonically treated in acetone, alcohol and deionized water in sequence, each time with an ultrasonic power of 160W for 20 minutes. After ultrasonication, it was dried with nitrogen gas.

[0032] S2, nitrogen plasma treatment and preparation of yttrium oxide coating The cleaned diamond substrate is placed inside the magnetron sputtering coating machine. The molecular pump and mechanical pump are turned on, and the vacuum level inside the chamber is ≤10. -4After passing through the chamber, nitrogen gas was introduced, and the chamber pressure was adjusted to 2 Pa, the gas flow rate to 160 sccm, and the power to 200 W. The diamond substrate was then treated for 150 min. After treatment, the diamond substrate was heated to 250 °C. Argon gas (Ar) was introduced at a flow rate of 40 sccm, and yttrium oxide (Y₂O₃) target was used for pre-sputtering at a sputtering power of 160 W for 5 min. After pre-sputtering, the baffle was opened to adjust the chamber pressure to 0.2 Pa, and sputtering continued at a sputtering power of 160 W for 400 min.

[0033] S3, Vacuum Annealing After sputtering, the diamond substrate coated with yttrium oxide was removed, placed in a tube furnace, evacuated to -0.08 MPa, heated to 300°C at a heating rate of 8°C / min, held for 2 hours, and then allowed to cool naturally to room temperature to obtain a diamond material with nitrogen vacancy color centers and yttrium oxide coating.

[0034] Example 5 A method for preparing a high-performance nitrogen-vacancy color center diamond material includes the following steps: S1. Electron irradiation treatment and cleaning of the diamond substrate. A diamond substrate (oriented (111)) was placed in an electron beam evaporation coating apparatus and irradiated with a 10kW electron gun for 120 minutes. After that, the diamond substrate was ultrasonically treated in acetone, alcohol and deionized water in sequence, each time with an ultrasonic power of 200W for 15 minutes. After ultrasonication, it was dried with nitrogen gas.

[0035] S2, nitrogen plasma treatment and preparation of yttrium oxide coating The cleaned diamond substrate is placed inside the magnetron sputtering coating machine. The molecular pump and mechanical pump are turned on, and the vacuum level inside the chamber is ≤10. -4 After passing through the chamber, nitrogen gas was introduced, and the chamber pressure was adjusted to 2 Pa, the gas flow rate to 160 sccm, and the power to 300 W. The diamond substrate was then treated for 240 min. After treatment, the diamond substrate was heated to 300 °C. Argon gas (Ar) was introduced at a flow rate of 80 sccm, and yttrium oxide (Y₂O₃) target was used for pre-sputtering at a sputtering power of 200 W for 3 min. After pre-sputtering, the baffle was opened to adjust the chamber pressure to 0.6 Pa, and sputtering continued at a sputtering power of 200 W for 200 min.

[0036] S3, Vacuum Annealing After sputtering, the diamond substrate coated with yttrium oxide was removed, placed in a tube furnace, evacuated to -0.08 MPa, heated to 900°C at a heating rate of 10°C / min, held for 2 hours, and then cooled naturally to room temperature to obtain a diamond material with nitrogen vacancy centers and yttrium oxide coating.

[0037] Comparative Example 1 In this comparative example, the diamond material is an untreated diamond substrate, which is cut into small substrates of 1cm × 1cm.

[0038] Comparative Example 2 The preparation method of the high-performance nitrogen-vacancy center diamond material in this comparative example is basically the same as that in Example 1, except that: in step S3, after sputtering, the diamond substrate coated with yttrium oxide is taken out, placed in a tube furnace, heated to 300°C at a heating rate of 8°C / min, held for 2 hours, and then naturally cooled to room temperature to obtain a diamond material with nitrogen-vacancy centers and yttrium oxide coating.

[0039] Comparative Example 3 A type with nitrogen vacancy (NV) - The method for preparing diamond materials with color centers and yttrium oxide coatings includes the following steps: P1, Clean diamond substrate The diamond substrate was ultrasonically treated sequentially in acetone, alcohol, and deionized water, each time using 180W ultrasonic power for 10 minutes. After ultrasonication, it was dried with nitrogen gas.

[0040] P2, Yttrium oxide coating The cleaned diamond substrate was placed inside the magnetron sputtering coating machine. The molecular and mechanical pumps were turned on, and the diamond substrate was heated to 300°C while a vacuum was being created. The vacuum level inside the magnetron sputtering coating machine was then increased to 10... -4 After Pa, argon gas (Ar) was introduced at a flow rate of 60 sccm, and yttrium oxide (Y2O3) target was used for pre-sputtering at a sputtering power of 180 W for 5 min. After pre-sputtering, the baffle was opened to adjust the chamber pressure to 0.4 Pa, and sputtering continued at a sputtering power of 180 W for 240 min.

[0041] P3, Vacuum Annealing After sputtering, the diamond substrate coated with yttrium oxide was removed, placed in a tube furnace, evacuated to -0.08 MPa, heated to 900 °C at a heating rate of 9 °C / min, held for 2 hours, and then cooled naturally to room temperature to obtain a diamond material with nitrogen vacancy color centers and yttrium oxide coating.

[0042] Performance testing The corrosion rates of the diamond materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested in extreme environments. The specific methods are as follows: The diamond materials prepared in Examples 1-3 and Comparative Examples 1-2 were partially masked with photoresist and placed in an etching machine. The mechanical and molecular pumps were turned on. After vacuuming, CF4 and O2 were introduced, the chamber pressure was adjusted to 15 mTorr, and the radio frequency power was adjusted to 800 W to excite F plasma for etching the samples for 1 hour. After etching, the samples were removed, placed in acetone for ultrasonic cleaning to remove the photoresist, and the etching rate was measured using a profilometer. The test results are as follows: Figure 4 As shown. From Figure 4 As can be seen above, in corrosive gases (the F free radicals generated by the decomposition of fluorine-containing gases are corrosive), the diamond material prepared in Example 1 has the lowest etching rate and the best corrosion resistance. The corrosion resistance of the diamond materials prepared in all examples is significantly better than that of the diamond materials in the comparative examples.

[0043] The NV (noise, radiation, and luminescence) of the diamond substrate used in this application, the diamond material with nitrogen vacancy centers and yttrium oxide coating prepared in Comparative Example 3, and the high-performance nitrogen vacancy center diamond material prepared in Example 1 were analyzed before and after annealing (the annealing conditions for Comparative Example 3 and Example 1 were the same) using a single-point photoluminescence method (excitation wavelength of 532 nm, laser power of 0.2 mW). - Strength was tested, and the results are as follows: Figure 5 and Figure 6 As shown. Figure 5 Figure (a) shows the photoluminescence (PL) spectra of the diamond substrate before and after annealing, and Figure (b) shows the PL spectra of the diamond material with nitrogen vacancy color centers and yttrium oxide coating prepared in Comparative Example 3 before and after annealing. Figure 6 The PL spectra of the high-performance nitrogen-vacancy center diamond material prepared in Example 1 before and after annealing. (NV of diamond) - The zero-phonon line is located at 637 nm. From Figure 5 As can be seen above, the NV of the diamond substrate before annealing and the diamond material with nitrogen vacancy centers and yttrium oxide coating... - The strengths of both are at a relatively low level (1755 for diamond substrates and 2280 for diamond materials with yttrium oxide coatings), but after annealing, the NV (vitamin N-value) of both the diamond substrate and the high-performance nitrogen-vacancy center diamond material increases significantly. -The intensities are located at 5218 and 13714, respectively. It can be seen that the intensity of nitrogen vacancy centers on the diamond substrate without yttrium oxide coating increased by 197.3% after annealing compared to before annealing; while the intensity of nitrogen vacancy centers on the diamond substrate with yttrium oxide coating increased by 501.5% after annealing compared to before annealing. This indicates that the yttrium oxide coating on the diamond substrate surface exhibits significant NV (nitrogen vacancy) enhancement during high-temperature annealing. - Intensity enhancement effect. From Figure 6 As can be seen above, the high-performance nitrogen-vacancy center diamond material prepared in Example 1 has a strength of 6621 before annealing and a strength of 50282 after annealing. Combining the schemes of Example 1 and Comparative Example 3, and... Figure 5 and Figure 6 The experimental results show that the yttrium oxide coating has a significant effect on NV during high-temperature annealing. - The strength was increased by 162.8%; nitrogen plasma treatment during high-temperature annealing improved the NV... - The strength was increased by 266.6%; nitrogen plasma treatment and yttrium oxide coating together improved NV strength during high-temperature annealing. - The strength increase was 863.6%; thus, it can be seen that, in the embodiments of this application, nitrogen plasma treatment and the yttrium oxide coating prepared on the diamond substrate surface significantly improve the NV (noise, vibration, and osmosis) content of the diamond substrate. - The intensity exhibits a significant synergistic effect. This is because during nitrogen plasma treatment, higher-energy nitrogen atoms enter the diamond lattice, increasing the concentration of substitutional nitrogen in the diamond. Substitutional nitrogen is essential for the formation of NV (non-nuclear) atoms. - One of the key elements of color centers. However, even with a high concentration of substituted nitrogen in the diamond substrate, the high-temperature annealing process still has a significant impact on NV (Non-Vacuum Injection) performance. - The effect on strength improvement is limited. However, yttrium oxide coatings significantly improve NV (noise, vibration, and radiative degradation) during high-temperature annealing. - The strength of the coating is important, but if the concentration of substituted nitrogen is not high enough, the yttrium oxide coating will affect NV. - The degree of strength improvement is also limited. Therefore, only when the substituted nitrogen concentration in the diamond substrate is sufficiently high through nitrogen plasma treatment can the yttrium oxide coating fully exert its NV benefits during high-temperature annealing. - The yttrium oxide film enhances strength. Simultaneously, during high-temperature annealing, it acts as a physical barrier, effectively suppressing carbon atom sublimation and oxidation-induced vacancy loss on the diamond surface. Furthermore, the different coefficients of thermal expansion between yttrium oxide and diamond may introduce compressive stress at the interface during annealing cooling, lowering the activation energy for vacancy migration and promoting vacancy diffusion towards nitrogen atoms. These factors collectively contribute to increased NV (Normative Intensity). - Increased concentration.

[0044] The embodiments described above are merely preferred embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by anyone skilled in the art. Any simple equivalent changes and modifications made based on the scope of protection of this application and the content of the specification should be included within the scope of protection of this application.

Claims

1. A method for preparing a high-performance nitrogen-vacancy color center diamond material, characterized in that, The following steps are involved: S1. The diamond substrate is subjected to electron irradiation treatment, and then the diamond substrate is cleaned; S2. The diamond substrate is subjected to nitrogen plasma treatment, and a yttrium oxide coating is deposited on the surface of the diamond substrate by magnetron sputtering. Specifically, the following steps are included: the cleaned diamond substrate from step S1 is placed in a magnetron sputtering coating machine, a vacuum is drawn, and after the vacuum level in the magnetron sputtering coating machine reaches the baseline vacuum, nitrogen gas is introduced to perform nitrogen plasma treatment on the diamond substrate. After the treatment is completed, the diamond substrate is heated, an inert gas is introduced, and a yttrium oxide target is used for pre-sputtering. After the pre-sputtering is completed, the pressure in the magnetron sputtering coating machine is reduced for the formal sputtering. S3. Anneal the diamond substrate with yttrium oxide coating under vacuum conditions.

2. The preparation method according to claim 1, characterized in that, The method for cleaning the diamond substrate in step S1 includes the following steps: ultrasonically cleaning the diamond substrate in acetone, alcohol and deionized water in sequence, using an ultrasonic power of 160~200W for 10~20 minutes each time; after ultrasonication, drying it with nitrogen gas.

3. The preparation method according to claim 1, characterized in that, The power of the electron gun used for electron irradiation in step S1 is 8~10kW, and the irradiation time is 120min; Or / and, the nitrogen plasma treatment power of the diamond substrate is 200~300W, the gas pressure is 2Pa, the gas flow rate is 160sccm, and the treatment time is 120~240min.

4. The preparation method according to claim 1, characterized in that, In step S2, the diamond substrate is heated to 250°C to 350°C; or / and the base vacuum is ≤10°C. -4 Pa.

5. The preparation method according to claim 1, characterized in that, The inert gas is Ar, and the gas flow rate is 40~80 sccm.

6. The preparation method according to claim 1, characterized in that, The pre-sputtering conditions are: sputtering for 3-8 minutes at a sputtering power of 160-200W under a pressure ≤2Pa; or / and the formal sputtering conditions are: sputtering for 200-400 minutes at a pressure of 0.2-0.6Pa and a sputtering power of 160-200W.

7. The preparation method according to claim 1, characterized in that, In step S3, the annealing temperature is 300~900℃ and the holding time is 1~3h.

8. The preparation method according to claim 1, characterized in that, The heating rate in step S3 is 8~10℃ / min.

9. The high-performance nitrogen-vacancy color center diamond material prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the diamond material according to claim 9 in the field of quantum sensing.

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