Method for preparing diamond super capacitor

Abstract

The invention discloses a method for preparing a diamond super capacitor, and belongs to the field of diamond application. Comprising the following steps: S1, depositing an ultrathin diamond film on a substrate material; s2, depositing a conductive thin film on the ultrathin diamond thin film to serve as a capacitor electrode, and stripping the ultrathin diamond thin film deposited with the conductive thin film from the substrate material; or, stripping the ultrathin diamond film from the substrate material, and depositing the conductive film on the stripped ultrathin diamond film to serve as the capacitor electrode; s3, the stripped ultrathin diamond film is curled around the metal electrode cylinder to form a cylinder; and S4, carrying out electrode packaging on the surface of the cylinder to form a capacitor. Compared with the prior art, the flexible ultrathin diamond thin film is prepared based on the chemical vapor deposition method, the conductive thin film is deposited on the flexible ultrathin diamond thin film, and the diamond super capacitor is formed through curling and electric polarization treatment, so that the application of the diamond thin film on the capacitor can be realized.

Description

Technical Field

[0001] The invention belongs to the field of diamond film applications, and in particular relates to a method for preparing a diamond supercapacitor. Background Art

[0002] As a highly specialized basic material, diamond boasts high thermal conductivity, a high breakdown electric field, high carrier mobility, and wide bandwidth, earning it the nickname "the ultimate semiconductor." Diamond also boasts exceptional chemical stability and optical properties, making it widely applicable in a variety of fields, including solid-state power devices, heat sinks, optical windows, electrochemical motors, and machining.

[0003] The combination of diamond's high breakdown electric field and high dielectric constant makes it an excellent material for manufacturing high-energy-density capacitors. However, natural diamond is not suitable for capacitor production due to its high price and limited material morphology. In recent years, the development of synthetic diamond using high-temperature and high-pressure methods and chemical vapor deposition has enabled laboratory-synthesized diamond to enter the stage of large-scale production, significantly reducing the cost of diamond and making the preparation of diamond-based supercapacitors feasible.

[0004] Products synthesized by high temperature and high pressure methods are still not suitable for the preparation of capacitors due to morphological limitations; although diamond films synthesized by chemical vapor deposition methods can theoretically be well applied to the preparation of capacitors, there is still a lack of feasible solutions to implement them in the industry. Summary of the Invention

[0005] To solve the above problems, the purpose of the present invention is to provide a method for preparing a diamond supercapacitor, by depositing a conductive film on a flexible ultra-thin diamond film, and forming a diamond supercapacitor after curling and polarization treatment, thereby enabling the application of diamond film in capacitors.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] The present invention provides a method for preparing a diamond supercapacitor, comprising the following steps:

[0008] S1: Depositing ultra-thin diamond film on substrate material;

[0009] S2: depositing a conductive film on the ultra-thin diamond film as a capacitor electrode, and peeling the ultra-thin diamond film with the conductive film deposited thereon from the substrate material;

[0010] Alternatively, the ultra-thin diamond film is peeled off from the substrate material, and then a conductive film is deposited on the peeled ultra-thin diamond film as a capacitor electrode;

[0011] S3: The peeled ultra-thin diamond film is rolled around the metal electrode cylinder to form a cylinder;

[0012] S4: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

[0013] Furthermore, before step S1, the substrate material is subjected to a nucleation treatment, and the nucleation treatment includes one of the following two methods:

[0014] Method 1: Clean the surface of the base material and then treat it with a diamond polishing liquid containing nano- and micron-level diamonds. Diamond particles are embedded in the surface of the base material and scratches are formed, which can promote the nucleation and subsequent growth of diamonds.

[0015] Method 2: Clean the surface of the base material, use plasma for surface pretreatment, use a diamond powder mixture, and form a diamond seed layer on the surface of the substrate by mechanical spin coating, which can promote the nucleation and subsequent growth of diamonds.

[0016] In method 2, the diamond powder size is less than 10 nm, and the matrix material of the mixed solution includes but is not limited to dimethyl sulfoxide, anhydrous ethanol, acetone, etc. The basic spin coating speed is 300-600 rpm, and the speed after acceleration is 3000-5000 rpm. The duration is 100-120 seconds.

[0017] Furthermore, in step S1 , the substrate material includes one of a single crystal silicon wafer, a polycrystalline silicon wafer or a rectangular silicon wafer, glass, and silicon carbide.

[0018] Furthermore, in step S1, the thickness of the ultra-thin diamond film is 0.1-50 μm.

[0019] Furthermore, in step S1, the growth conditions of the ultra-thin diamond film are: the carrier gas is H2, with a flow range of 300-1000sccm; the carbon source is CH4, with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

[0020] Furthermore, in step S2, a conductive film is deposited on the ultra-thin diamond film by using a vapor deposition method, and the vapor deposition method includes a microwave plasma chemical vapor deposition method and a hot wire chemical vapor deposition method.

[0021] Furthermore, in step S2, the material of the conductive film is a metal material, graphite or ITO, and the thickness of the conductive film is 0.1-50 um.

[0022] Furthermore, the metal material includes aluminum, copper, molybdenum, titanium, tungsten, and gold.

[0023] Furthermore, in step S2, the ultra-thin diamond film is peeled off from the base material by using a tape stripping method, a chemical etching method or a high-low temperature cycle method.

[0024] Furthermore, the tape stripping method is: using tape to bond and peel the ultra-thin diamond film from the base material.

[0025] Furthermore, the chemical etching method is: using a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH to dissolve the base material, so that the ultra-thin diamond film is detached from the base material.

[0026] Furthermore, in step S4, another electrode is added to the outer surface of the cylinder to form the positive and negative poles of the capacitor respectively with the conductive film, and then insulation packaging is performed to form a complete capacitor.

[0027] The beneficial effects of the present invention are as follows: compared with the prior art, the present application prepares a flexible ultra-thin diamond film based on the chemical vapor deposition method, and then deposits a conductive film on the flexible ultra-thin diamond film. After curling and polarization treatment, a diamond supercapacitor is formed, thereby enabling the application of diamond film on capacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a process flow chart of Example 1.

[0029] Figure 2 It is a process flow chart of Example 2.

[0030] Figure 3 This is a process flow chart of Example 3.

[0031] Figure 4 This is a process flow chart of Example 4.

[0032] Figure 5-Figure 12 1 and 2 are diagrams illustrating the preparation process of the diamond supercapacitor according to Examples 1 and 2.

[0033] Figures 13-19 1 is a diagram of the preparation process of the diamond supercapacitor of Example 3 and Example 4.

[0034] Figure 20 This is a schematic diagram of a structure in which multiple metal-coated diamond films in Example 1 and Example 2 are wound together to form a capacitor.

[0035] Figure 21 Schematic diagram of the structure of the diamond supercapacitor prepared in Examples 1-4.

[0036] Figure 22 Schematic diagram of the cross-sectional structure of the diamond supercapacitor prepared in Examples 1-4. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0038] To achieve the above object, the technical solution of the present invention is as follows:

[0039] Example 1:

[0040] like Figure 1 As shown, this embodiment provides a method for preparing a diamond supercapacitor, comprising the following steps:

[0041] S11: performing nucleation treatment on the single crystal silicon wafer to embed diamond particles into the surface of the substrate material and form scratches;

[0042] S12: Depositing ultra-thin diamond films with a thickness of 0.1-50 μm on single crystal silicon wafers by microwave plasma chemical vapor deposition;

[0043] S13: depositing a conductive film on the ultra-thin diamond film as a capacitor electrode, and peeling the ultra-thin diamond film on which the conductive film is deposited from the single crystal silicon wafer;

[0044] S14: rolling the peeled ultra-thin diamond film around the metal electrode cylinder to form a cylinder;

[0045] S15: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

[0046] Furthermore, in step S12, the growth conditions of the ultra-thin diamond film are: the carrier gas is H2, with a flow range of 300-1000sccm; the carbon source is CH4, with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

[0047] Furthermore, in step S13, the conductive film is made of a metal material such as aluminum or copper, and the thickness of the conductive film is 0.1-50 um.

[0048] Furthermore, in step S13, the ultra-thin diamond film is peeled from the single-crystalline silicon wafer using a tape stripping method or a chemical etching method. The tape stripping method involves using tape to peel the ultra-thin diamond film from the single-crystalline silicon wafer. The chemical etching method involves using a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH to dissolve the single-crystalline silicon wafer, thereby separating the ultra-thin diamond film from the single-crystalline silicon wafer.

[0049] Example 2:

[0050] like Figure 2 As shown, this embodiment provides a method for preparing a diamond supercapacitor, comprising the following steps:

[0051] S21: performing nucleation treatment on the single crystal silicon wafer to embed diamond particles into the surface of the substrate material and form scratches;

[0052] S22: peeling the ultra-thin diamond film from the single crystal silicon wafer, and then depositing a conductive film on the peeled ultra-thin diamond film as a capacitor electrode;

[0053] S23: depositing a conductive film on the ultra-thin diamond film as a capacitor electrode, and peeling the ultra-thin diamond film on which the conductive film is deposited from the substrate material;

[0054] S24: rolling the peeled ultra-thin diamond film around the metal electrode cylinder to form a cylinder;

[0055] S25: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

[0056] Furthermore, in step S22, the growth conditions of the ultra-thin diamond film are as follows: the carrier gas is H2 with a flow range of 300-1000sccm; the carbon source is CH4 with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

[0057] Furthermore, in step S23, the conductive film is made of a metal material such as aluminum or copper, and the thickness of the conductive film is 0.1-50 um.

[0058] Furthermore, in step S23, the ultra-thin diamond film is peeled from the single-crystalline silicon wafer using a tape stripping method or a chemical etching method. The tape stripping method involves using tape to peel the ultra-thin diamond film from the single-crystalline silicon wafer. The chemical etching method involves using a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH to dissolve the single-crystalline silicon wafer, thereby separating the ultra-thin diamond film from the single-crystalline silicon wafer.

[0059] In the above-mentioned embodiment 1 and embodiment 2, the specific manufacturing process of the capacitor is shown in FIG. Figure 5-12 For details, see Figure 6 In step S11 or step S21, a nucleation process is performed on the single crystal silicon wafer and a nucleation process is performed on the substrate material. The nucleation process includes one of the following two methods:

[0060] Method 1: Clean the surface of the base material and then treat it with a diamond polishing liquid containing nano- and micron-level diamonds. Diamond particles are embedded in the surface of the base material and scratches are formed, which can promote the nucleation and subsequent growth of diamonds.

[0061] Method 2: Clean the surface of the base material, use plasma for surface pretreatment, use a diamond powder mixture, and form a diamond seed layer on the surface of the substrate by mechanical spin coating, which can promote the nucleation and subsequent growth of diamonds.

[0062] In method 2, the diamond powder size is less than 10 nm, and the matrix material of the mixed solution includes but is not limited to dimethyl sulfoxide, anhydrous ethanol, acetone, etc. The basic spin coating speed is 300-600 rpm, and the speed after acceleration is 3000-5000 rpm. The duration is 100-120 seconds.

[0063] See also Figure 11-12 In step S15 and step S25, another electrode is added to the outer surface of the cylinder to form the positive and negative electrodes of the capacitor with the conductive film respectively, and then the capacitor is insulated and packaged to form a complete capacitor; the structural diagram of the capacitor after forming is shown in FIG. Figure 21-22 .

[0064] Also, see Figure 20 As shown, in the above-mentioned Examples 1 and 2, the base material uses a single crystal silicon wafer. Due to the limited size of the single crystal silicon wafer, the size of the single metallized diamond film is also small. In order to achieve the goal of large capacitance, multiple metal-coated diamond films can be wound together to form a capacitor.

[0065] Example 3:

[0066] like Figure 3 As shown, this embodiment provides a method for preparing a diamond supercapacitor, comprising the following steps:

[0067] S31: performing nucleation treatment on the polycrystalline silicon wafer to embed diamond particles into the surface of the polycrystalline silicon wafer and form scratches;

[0068] S32: Depositing ultra-thin diamond films with a thickness of 0.1-50 μm on polycrystalline silicon wafers by hot-wire chemical vapor deposition;

[0069] S33: depositing a conductive film on the ultra-thin diamond film as a capacitor electrode, and peeling the ultra-thin diamond film on which the conductive film is deposited from the polycrystalline silicon wafer;

[0070] S34: rolling the peeled ultra-thin diamond film around the metal electrode cylinder to form a cylinder;

[0071] S35: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

[0072] Furthermore, in step S32, the growth conditions of the ultra-thin diamond film are as follows: the carrier gas is H2 with a flow range of 300-1000sccm; the carbon source is CH4 with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

[0073] Furthermore, in step S33, the conductive film is made of a metal material such as aluminum or copper, and the thickness of the conductive film is 0.1-50 um.

[0074] Furthermore, in step S33, the ultra-thin diamond film is peeled from the polycrystalline silicon wafer using a tape stripping method or a chemical etching method. The tape stripping method involves using tape to peel the ultra-thin diamond film from the polycrystalline silicon wafer. The chemical etching method involves using a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH, to dissolve the polycrystalline silicon wafer, thereby separating the ultra-thin diamond film from the polycrystalline silicon wafer.

[0075] Furthermore, in step S35, another electrode is added to the outer surface of the cylinder to form the positive and negative poles of the capacitor with the conductive film respectively, and then insulation packaging is performed to form a complete capacitor.

[0076] Example 4:

[0077] like Figure 4 As shown, this embodiment provides a method for preparing a diamond supercapacitor, comprising the following steps:

[0078] S41: performing nucleation treatment on the rectangular silicon wafer to embed diamond particles into the surface of the rectangular silicon wafer and form scratches;

[0079] S42: Depositing ultra-thin diamond films with a thickness of 0.1-50 μm on rectangular silicon wafers by hot-filament chemical vapor deposition;

[0080] S43: peeling the ultra-thin diamond film from the rectangular silicon wafer, and then depositing a conductive film on the peeled ultra-thin diamond film as a capacitor electrode;

[0081] S44: rolling the peeled ultra-thin diamond film around the metal electrode cylinder to form a cylinder;

[0082] S45: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

[0083] Furthermore, in step S42, the growth conditions of the ultra-thin diamond film are: the carrier gas is H2, with a flow range of 300-1000sccm; the carbon source is CH4, with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

[0084] Furthermore, in step S43, the conductive film is made of a metal material such as aluminum or copper, and the thickness of the conductive film is 0.1-50 um.

[0085] Furthermore, in step S43, the ultra-thin diamond film is peeled from the rectangular silicon wafer using a tape stripping method or a chemical etching method. The tape stripping method involves using tape to peel the ultra-thin diamond film from the rectangular silicon wafer. The chemical etching method involves using a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH, to dissolve the rectangular silicon wafer, thereby separating the ultra-thin diamond film from the rectangular silicon wafer.

[0086] Furthermore, in step S45, another electrode is added to the outer surface of the cylinder to form the positive and negative poles of the capacitor with the conductive film respectively, and then insulation packaging is performed to form a complete capacitor.

[0087] In the above-mentioned embodiment 3 and embodiment 4, the specific manufacturing process of the capacitor can be found in Figure 13-19 For details, see Figure 14 In step S31 or step S41, a nucleation process is performed on the polycrystalline silicon wafer or rectangular silicon wafer substrate material. The nucleation process is performed on the substrate material. The nucleation process includes one of the following two methods:

[0088] Method 1: Clean the surface of the base material and then treat it with a diamond polishing liquid containing nano- and micron-level diamonds. Diamond particles are embedded in the surface of the base material and scratches are formed, which can promote the nucleation and subsequent growth of diamonds.

[0089] Method 2: Clean the surface of the base material, use plasma for surface pretreatment, use a diamond powder mixture, and form a diamond seed layer on the surface of the substrate by mechanical spin coating, which can promote the nucleation and subsequent growth of diamonds.

[0090] In method 2, the diamond powder size is less than 10 nm, and the matrix material of the mixed solution includes but is not limited to dimethyl sulfoxide, anhydrous ethanol, acetone, etc. The basic spin coating speed is 300-600 rpm, and the speed after acceleration is 3000-5000 rpm. The duration is 100-120 seconds.

[0091] See also Figure 18-19In step S35 and step S45, another electrode is added to the outer surface of the cylinder to form the positive and negative electrodes of the capacitor with the conductive film respectively, and then the capacitor is insulated and packaged to form a complete capacitor; the structural diagram of the capacitor after forming is shown in FIG. Figure 21-22 .

[0092] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a diamond supercapacitor, characterized in that: The following steps are involved: S1: Depositing ultra-thin diamond film on substrate material; S2: depositing a conductive film on the ultra-thin diamond film as a capacitor electrode, and peeling the ultra-thin diamond film with the conductive film deposited thereon from the substrate material; Alternatively, the ultra-thin diamond film is peeled off from the substrate material, and then a conductive film is deposited on the peeled ultra-thin diamond film as a capacitor electrode; S3: The peeled ultra-thin diamond film is rolled around the metal electrode cylinder to form a cylinder; S4: Electrode packaging is performed on the surface of the cylinder to form a capacitor.

2. The method for preparing a diamond supercapacitor according to claim 1, wherein: Before step S1, the substrate material is subjected to a nucleation treatment, and the nucleation treatment method includes one of the following two methods: Method 1: Clean the surface of the substrate material and then treat it with a nano- and micro-level diamond polishing solution to embed diamond particles into the surface of the substrate material and form scratches, which can promote the nucleation and subsequent growth of diamonds. Method 2: Clean the surface of the base material, use plasma for surface pretreatment, use a diamond powder mixture, and form a diamond seed layer on the surface of the substrate by mechanical spin coating, which can promote the nucleation and subsequent growth of diamonds.

3. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S1 , the substrate material includes one of a single crystal silicon wafer, a polycrystalline silicon wafer or a rectangular silicon wafer, glass, and silicon carbide.

4. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S1, the thickness of the ultra-thin diamond film is 0.1-50 μm.

5. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S1, the growth conditions of the ultrathin diamond film are as follows: the carrier gas is H2 with a flow range of 300-1000sccm; the carbon source is CH4 with a flow rate of 2-12% of H2; the auxiliary gases are nitrogen, oxygen and argon, and the auxiliary gas content is 1-1000ppm.

6. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S2, a conductive film is deposited on the ultra-thin diamond film by using a vapor deposition method, and the vapor deposition method includes a microwave plasma chemical vapor deposition method and a hot wire chemical vapor deposition method.

7. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S2, the conductive film is made of metal, graphite or ITO, and the thickness of the conductive film is 0.1-50 μm.

8. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S2, the ultra-thin diamond film is peeled off from the base material by using a tape stripping method, a chemical etching method or a high-low temperature cycle method.

9. The method for preparing a diamond supercapacitor according to claim 8, wherein: The tape stripping method is as follows: using tape to bond and peel the ultra-thin diamond film from the base material; The chemical etching method is to use a mixed acidic solution of HF and HNO3, or an alkaline solution of NaOH or KOH to dissolve the base material, so that the ultra-thin diamond film is bonded and separated from the base material.

10. The method for preparing a diamond supercapacitor according to claim 1, wherein: In step S4, another electrode is added to the outer surface of the cylinder to form the positive and negative poles of the capacitor with the conductive film respectively, and then insulation packaging is performed to form a complete capacitor.

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