Beta ray three-dimensional emission source with high emissivity, preparation method and application
By fabricating a three-dimensional pyramid structure on a flexible substrate and employing an electrodeposition-free technique, the problems of weak coating adhesion and low raw material utilization in micro-β radiation sources were solved, thus realizing a β-ray emission source with high emissivity and efficient energy conversion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIDIAN UNIV
- Filing Date
- 2023-11-27
- Publication Date
- 2026-07-07
AI Technical Summary
Existing technologies for preparing miniature beta radiation sources suffer from problems such as low raw material utilization, low output power, and low energy conversion efficiency due to the relatively thick radiation source. Furthermore, traditional deposition techniques are limited by conductive substrates or result in weak coating adhesion that makes the coating prone to detachment.
A flexible substrate with a three-dimensional pyramid structure was prepared by wet etching and template transfer, and a 63Ni metal layer was uniformly deposited on its surface by electroless deposition. A polymer adhesion layer was used to enhance the adhesion of the metal particles, thereby achieving uniform deposition of 63Ni.
It improves β-ray emissivity, enhances coating adhesion, is suitable for micro-devices, expands application scenarios, and improves output power, energy conversion efficiency, and raw material utilization.
Smart Images
Figure CN117637229B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of micro nuclear battery technology, specifically to a three-dimensional β-ray emission source with high emissivity, its preparation method, and its application. Background Technology
[0002] Nuclear energy, as the ultimate energy source in the universe, possesses advantages unmatched by other energy sources. The decay of isotopes is accompanied by the stable release of thermal and radiative energy (alpha, beta, and gamma rays). Converting thermal and radiative energy into electrical energy can provide an energy solution for special scenarios where stable energy input is unavailable in extreme environments and equipment requires long-term operation. For example, the decay thermoelectric battery developed by the Institute of Atomic Energy and the decay thermophotovoltaic system developed by MIT are typical examples of high-power, large-scale nuclear batteries, and have already been applied in aerospace engineering. As a representative of micro nuclear batteries, beta-voltaic batteries can serve as an ideal power source for small distributed systems, primarily because: first, beta-voltaic batteries can operate continuously for years or even decades at extreme temperatures (-50°C to 150°C); second, the energy of the beta particles is very low, and compared to alpha and gamma rays, these low-energy beta particles have minimal radiation damage effects on the nuclear battery's transducer and other surrounding electronic devices, and are easy to protect against; third, compared to alpha and gamma radiation sources, the energy density of beta rays is more suitable for the power density requirements of small distributed systems for micro power supplies. However, β-volt batteries have drawbacks such as low output power, low energy conversion efficiency, and low energy density.
[0003] β-radiation source materials mainly include 3 T, 33 P, 33 S, 63 Ni、 85 Kr、 90 Sr、 90 Y、 106 Ru、 147 Pm, 204 Tl, where 147 Pm, 204 Tl decay is accompanied by gamma rays, making it difficult to protect against. Other isotopes have longer half-lives and can serve as long-lived radiation sources. 3 T, 63 Ni、 85 Kr、 90 Sr, however 85 Kr and 90 The maximum β-particle energies of Sr reach 687 keV and 546 keV, respectively, exceeding the radiation damage threshold of most semiconductor materials; therefore... 3 T and 63 Ni is theoretically the ideal choice for a beta radiation source. However, 3The production of hydrogen isotopes is currently hampered by the technological bottleneck of hydrogen isotope separation and enrichment, and therefore cannot meet application demands. Thus, at this stage... 63 Ni is the optimal choice for a beta radiation source. 63 Ni decays, releasing beta particles with sustained energy; its half-life is approximately 100 years. The surface activity of the beta radiation source determines the energy input of the beta-volt transducer; surface activity is related to specific activity (isotope intrinsic parameter) and self-absorption effect. Currently, the preparation of... 63 The main method for Ni radiation sources is to use an electrodeposition process, which involves electrodepositing on a metal substrate. 63 NiCl2 electrolyte 63 Currently, the main metal substrates used for Ni are nickel and copper substrates; however, existing processes result in relatively thick radiation sources, making them unsuitable for micro-devices. Current processes produce nickel layers with a thickness of approximately 10 μm. Research indicates that… 63 Ni has a self-shielding effect. When the thickness of the nickel layer increases from 2 μm to 4 μm, although the amount of raw material doubles, the corresponding power density only increases by 7.3%. Therefore, thicker radiation sources have the problem of low raw material utilization.
[0004] Li Hao and others were in 63 In the paper "Design and Fabrication of Nickel Thin Film Source for Ni-Si Radiation Voltage Cell" (Journal of Tsinghua University, 2017, 57(8)), nickel thin film was deposited on the surface of ITO using electrodeposition. 63 A Ni metal layer was formed using ITO as the negative electrode and nickel foam as the positive electrode. The water bath temperature was 25°C, the electrochemical workstation output current was constant at 100mA, the initial voltage was 1.5V, and the electroplating time was 40 minutes, resulting in a final thickness of 1.94μm. 63 Ni metal coating. The deposition time can be effectively controlled. 63 The thickness of the Ni metal coating. This work utilizes electrochemical deposition technology to effectively deposit on the surface of a conductive substrate. 63 Ni metal plating, however, requires the substrate to be a conductive material and an external power source to complete the process. 63 The deposition of Ni metal layers severely limits its application scenarios.
[0005] In their study, "Study of the Electroless Deposition of Ni for Betavoltaic Battery Using PN Junction without Seed Layer" (Journal of Nanomaterials, 2015, 3-3), Jin Joo Kin et al. prepared a Ni metal layer on a silicon substrate using an electroless deposition technique. This technique involved using 0.1M nickel sulfate, 0.23M sodium hypophosphite, 0.07M sodium citrate, 0.06M sodium acetate, and 4nM lead acetate as stabilizers. Nickel sulfate was the main salt, sodium hypophosphite was the reducing agent, and sodium citrate and sodium acetate were used as complexing agents. The pH of the deposition solution was adjusted to 10 by adding sodium hydroxide, and the solution was heated to 75°C. The deposited solution had a size of 5×5 mm. 3 A silicon wafer was used as the substrate. Before electroless Ni plating, the wafer was immersed in a 10% HCl solution for 40 seconds and then rinsed with distilled water. The cleaned wafer was placed in a beaker for 20 minutes without any pretreatment, activation, or sensitization. Subsequently, it was rinsed with distilled water and dried in a vacuum at 90°C for 1 hour, resulting in a silicon wafer with a 50nm thick Ni metal layer deposited on its surface through electroless plating. Compared to electrochemical deposition, this electroless deposition technique is not limited to depositing Ni metal layers on conductive substrates. However, this technique relies on surface physical adsorption to deposit Ni metal onto the silicon substrate surface, resulting in weak adhesion between the Ni metal layer and the deposition layer, making it prone to detachment, and also requires a high reaction temperature. Summary of the Invention
[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a three-dimensional β-ray emission source with high emissivity, its preparation method, and its application. 63 Ni was used as a β-radiation source to prepare a substrate with a three-dimensional pyramid structure and controllable dimensions via wet etching and template transfer. Electroless deposition was then used to... 63 A Ni radiation source was uniformly deposited on the surface of a pyramid-shaped substrate with a three-dimensional structure to prepare a material with high emissivity. 63 Ni three-dimensional structure has the characteristics of low output power, high energy conversion efficiency, high energy density, and suitability for micro-devices and thicker radiation sources. It also has the advantages of high raw material utilization, wide application scenarios, and low reaction temperature.
[0007] A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between molecular functional groups and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0008] The flexible substrate is made of polydimethylsiloxane (PDMS), polyurethane, or polystyrene-polyisoprene-polystyrene.
[0009] The polymer adhesive layer is polyethyleneimine.
[0010] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0011] Step 1, using photolithography and wet etching on <100> Patterned rectangular matrix arrays are prepared on the surface of p-type silicon wafers. Then, the exposed silicon dioxide (SiO2) pattern on the silicon wafer surface is etched with hydrofluoric acid (HF) buffer solution. After drying at 60-90℃, it is transferred to a mixed solution of isopropanol and potassium hydroxide for anisotropic etching for 2-5 hours to obtain a silicon mold with a micro pyramid structure. The mass ratio of isopropanol to potassium hydroxide is (1-3):(2-4). The remaining SiO2 layer on the surface of the silicon mold is etched with hydrofluoric acid (HF) buffer solution to obtain a reusable silicon mold. The pretreated mixture is spin-coated onto the reusable silicon mold and cured at 75-90℃ for 2-5 hours to obtain a polydimethylsiloxane (PDMS) film. The PDMS film is peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on the surface.
[0012] Step 2: Modify a polymer adhesion layer onto the substrate with a three-dimensional pyramid structure obtained in Step 1. Immerse the substrate with the three-dimensional pyramid structure in a solution containing one or more of the following at a mass concentration of 0.1-100 mg / ml: tannic acid, lignin, fumaric acid, and malic acid, and polyethyleneimine (weight average molecular weight M). w =600-70000, 0.01-1 mg / mL) reacted in Tris buffer solution (0.1-100 mM) for 1-24 h, followed by washing and drying;
[0013] Step 3: Immerse the substrate modified with the polymer adhesion layer obtained in Step 2 in the catalyst for 5-60 minutes, rinse with deionized water, and then place it in a solution containing... 63 Electroless deposition of a polymer adhesion layer is performed on the substrate surface in a Ni metal ion salt electroless plating solution at room temperature. 63 A Ni metal layer was used to obtain a three-dimensional β-ray emission source with high emissivity.
[0014] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1; the pretreatment process is to degas the mixture for 30-90 minutes.
[0015] In step 1, the area of a single graphic in the patterned rectangular matrix array ranges from 5um × 5um to 200um × 200um.
[0016] The polydimethylsiloxane (PDMS) can be replaced by polyurethane or polystyrene-polyisoprene-polystyrene.
[0017] The deposition in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The thickness of the Ni metal layer is 0.1-2 μm; 63 The average sheet resistance of the Ni metal layer is 0.1-1 Ω / sq.
[0018] In step 3, the catalyst is an ammonium tetrachloropalladium solution with a concentration of 0.01-100 mmol / L.
[0019] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of one of nickel sulfate-63 hexahydrate, nickel chloride-63 hexahydrate, or nickel nitrate-63 hexahydrate (0.01-1 mol / L), sodium citrate (0.01-1 mol / L), and lactic acid (0.01-1 mol / L). Solution B is dimethylamine borane with a concentration of 0.01-10 mol / L. 63 When electroless Ni deposition is performed, solution A and solution B are mixed at a volume ratio of (1-100):1, and then the pH is adjusted to 7-10 with ammonia. Deposition is carried out at 25-50℃ for 1-24 hours.
[0020] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] 1. This invention prepares a substrate with a three-dimensional pyramid structure and controllable size by wet etching and template transfer, thus effectively avoiding the self-shielding effect and improving the β-ray emissivity.
[0023] 2. This invention utilizes a flexible substrate with a three-dimensional pyramid structure, and the surface of the flexible substrate is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through intermolecular forces between the molecules and the metal particles. 63 Ni particles are adsorbed onto the surface of a flexible substrate, thus enabling them to be applied to any substrate surface. 63 Ni metal layer deposition is characterized by its low cost, wide applicability, and high efficiency.
[0024] In summary, the present invention selects 63 Ni was used as a β-radiation source to prepare a substrate with a three-dimensional pyramid structure and controllable dimensions via wet etching and template transfer. Electroless deposition was then used to... 63 A Ni radiation source was uniformly deposited on the surface of a pyramid-shaped substrate with a three-dimensional structure to prepare a material with high emissivity. 63 Ni has a three-dimensional structure, thus it has the characteristics of low output power, high energy conversion efficiency, high energy density, and suitability for micro-devices and thicker radiation sources, as well as high material utilization. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the structure of the present invention.
[0026] Figure 2 This is a schematic diagram of a three-dimensional pyramid structure, in which... Figure 2 (a) is a schematic diagram of a periodic three-dimensional pyramid structure. Figure 2 (b) is a schematic diagram of a randomly distributed three-dimensional pyramid structure.
[0027] Figure 3 for 63 Scanning electron microscope image of the Ni metal layer, in which... Figure 3 (a) Deposition 63 Scanning electron microscope image of the Ni metal layer. Figure 3 (b) 63 Scanning electron microscope image of the cross-section of the Ni metal layer.
[0028] Figure 4 For example 1, the deposited 63 Sheet resistance distribution of Ni metal layer.
[0029] Figure 5 Example 3 63 Scanning electron microscope image of the Ni metal layer, in which... Figure 5 (a) Deposition 63 Scanning electron microscope image of the Ni metal layer. Figure 5 (b) 63 Scanning electron microscope image of the cross-section of the Ni metal layer.
[0030] Figure 6 For example, the deposited in Example 3 63 Sheet resistance distribution of Ni metal layer. Detailed Implementation
[0031] The present invention will now be described in detail with reference to the accompanying drawings.
[0032] Example 1
[0033] See Figure 1 A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between the molecules and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0034] The flexible substrate is made of polydimethylsiloxane (PDMS).
[0035] The polymer adhesive layer is polyethyleneimine.
[0036] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0037] Step 1, using photolithography and wet etching on <100> Patterned rectangular matrix arrays were fabricated on the surface of a p-type silicon wafer. Then, the exposed silicon dioxide (SiO2) pattern on the wafer surface was etched using a hydrofluoric acid (HF) buffer solution, effectively removing the surface SiO2 passivation layer. After drying at 60°C, the wafer was transferred to a mixed solution of isopropanol and potassium hydroxide for anisotropic etching for 2 hours, yielding a silicon mold with a micro-pyramid structure. The mass ratio of isopropanol to potassium hydroxide was 1:2. The remaining SiO2 layer on the surface of the silicon mold was etched using a hydrofluoric acid (HF) buffer solution, resulting in a reusable silicon mold. The pretreated mixture was spin-coated onto the reusable silicon mold and cured at 75°C for 2 hours to obtain a polydimethylsiloxane (PDMS) film. The PDMS film was then peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on its surface. (See also...) Figure 2 (a) shows a substrate with a periodic three-dimensional pyramid structure;
[0038] Step 2: Place the polydimethylsiloxane (PDMS) substrate with a three-dimensional pyramidal structure obtained in Step 1 onto tannic acid (5 mg / mL) and polyethyleneimine (weight-average molecular weight M). w The reaction was carried out in a 10 mM (600 mg / mL) Tris buffer solution for 5 hours. After the reaction was completed, the mixture was washed three times with deionized water, placed on a clean petri dish, and dried in a vacuum oven at 40°C. This completed the modification of the polymer adhesion layer on the polydimethylsiloxane (PDMS) substrate with a three-dimensional pyramid structure.
[0039] Step 3: Immerse the polydimethylsiloxane (PDMS) substrate modified with the polymer adhesion layer obtained in Step 2 into 0.5 mmol / L ammonium tetrachloropalladate for 5 minutes. After a thorough ion exchange process, the polymer adhesion layer adsorbs tetrachloropalladate ions. Then, rinse with plenty of deionized water to remove any unadsorbed tetrachloropalladate ions. Finally, immerse the polydimethylsiloxane (PDMS) substrate with adsorbed tetrachloropalladate ions into... 63 A three-dimensional β-ray emission source with high emissivity was obtained by depositing Ni in a chemical plating solution at 25°C for 1 hour.
[0040] See Figure 2 The deposited in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The Ni metal layer has a thickness of 1 μm.
[0041] In step 1, the area of a single graphic in the patterned rectangular matrix array is 5um × 5um.
[0042] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1; the pretreatment process is to degas the mixture for 30 minutes.
[0043] See Figure 3 In step 3 63 The average sheet resistance of the Ni metal layer is 0.377 Ω / sq.
[0044] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of nickel sulfate-63 hexahydrate (0.1 mol / L), sodium citrate (0.2 mol / L), and lactic acid (0.1 mol / L); solution B is composed of dimethylamine borane with a concentration of 0.05 mol / L. Each time... 63 During Ni electroless deposition, solution A and solution B are mixed in a 1:1 volume ratio, and then the pH is adjusted to 7 with ammonia. Deposition is carried out at 25°C for 1 hour to obtain a three-dimensional β-ray emission source with high emissivity.
[0045] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0046] Example 2
[0047] See Figure 1A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between the molecules and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0048] The flexible substrate is polydimethylsiloxane (PDMS), and the polymer adhesive layer is polyethyleneimine.
[0049] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0050] Step 1, directly use wet etching on <100> Patterned rectangular matrix arrays were prepared on the surface of a p-type silicon wafer. The cut silicon wafer was then etched at 82°C in a mixed solution of 3 mol / L isopropanol and 4 mol / L potassium hydroxide for 3 hours to obtain a silicon mold with a randomly distributed three-dimensional pyramid structure. The pretreated mixture was spin-coated onto the silicon mold with the randomly distributed three-dimensional pyramid structure and cured at 90°C for 5 hours to obtain a polydimethylsiloxane (PDMS) film. The PDMS film was then peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on its surface. (See also...) Figure 2 (b) shows a substrate with a three-dimensional pyramid structure exhibiting random distribution;
[0051] Step 2: Place the polydimethylsiloxane (PDMS) substrate with a three-dimensional pyramidal structure obtained in Step 1 onto tannic acid (0.1 mg / mL) and polyethyleneimine (weight average molecular weight M). w The reaction was carried out in a 0.1 mM Tris buffer solution (70000, 0.01 mg / mL) for 1 hour. After the reaction was completed, the mixture was washed three times with deionized water, placed on a clean petri dish, and dried in a vacuum oven at 40°C. This completed the modification of the polymer adhesion layer on the polydimethylsiloxane (PDMS) substrate with a three-dimensional pyramid structure.
[0052] Step 3: Immerse the polydimethylsiloxane (PDMS) substrate modified with the polymer adhesion layer obtained in Step 2 into 0.01 mmol / L ammonium tetrachloropalladate for 60 minutes. After sufficient ion exchange, the polymer adhesion layer adsorbs tetrachloropalladate ions. Then, rinse with plenty of deionized water to remove the unadsorbed tetrachloropalladate ions. Finally, immerse the polydimethylsiloxane (PDMS) substrate with adsorbed tetrachloropalladate ions into... 63 A three-dimensional β-ray emission source with high emissivity was obtained by depositing Ni in a chemical plating solution at 25°C for 1 hour.
[0053] The deposition in step 363 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The Ni metal layer thickness is 0.1 μm.
[0054] In step 1, the area of a single graphic in the patterned rectangular matrix array is 200um × 200um.
[0055] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1. The pretreatment process is to degas the mixture for 30 minutes.
[0056] In step 3 63 The average sheet resistance of the Ni metal layer is 0.1 Ω / sq.
[0057] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of nickel sulfate-63 hexahydrate (0.01 mol / L), sodium citrate (0.01 mol / L), and lactic acid (0.01 mol / L); solution B is composed of dimethylamine borane with a concentration of 0.05 mol / L. Each time... 63 During Ni electroless deposition, solution A and solution B were mixed at a volume ratio of 10:1, and the pH was adjusted to 9 with ammonia. Deposition was carried out at 50°C for 24 hours to obtain a three-dimensional β-ray emission source with high emissivity.
[0058] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0059] Example 3
[0060] See Figure 1 A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between the molecules and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0061] The flexible substrate is polydimethylsiloxane (PDMS), and the polymer adhesive layer is polyethyleneimine.
[0062] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0063] Step 1, using photolithography technology on <100> A patterned rectangular matrix array was prepared on the surface of a p-type silicon wafer. Then, the exposed silicon dioxide (SiO2) pattern was etched using a hydrofluoric acid (HF) buffer solution, effectively removing the surface SiO2 passivation layer. A silicon mold with a micropyramid structure was prepared by anisotropic etching for 3 hours in a 2 mol / L isopropanol and 3 mol / L potassium hydroxide mixture in a 90°C oven. The remaining SiO2 layer was etched using the HF buffer solution to obtain the silicon mold. A polydimethylsiloxane (PDMS) matrix was mixed with a curing agent (10:1), and the mixture was degassed in a vacuum for 30 minutes to remove air bubbles. The mixture was then spin-coated onto the silicon mold and cured at 80°C for 3 hours to obtain a PDMS film. The PDMS film was then peeled off from the silicon mold, finally yielding a substrate with a three-dimensional pyramid structure on its surface. See [link to relevant documentation]. Figure 2 (a) shows a substrate with a periodic three-dimensional pyramid structure;
[0064] Step 2: Place the polydimethylsiloxane (PDMS) substrate with a three-dimensional pyramidal structure obtained in Step 1 onto a substrate containing malic acid (100 mg / mL) and polyethyleneimine (weight-average molecular weight M). w The reaction was carried out in a Tris buffer solution (100 mM) containing 40000 mg / mL (0.1 mg / mL) for 10 hours. After the reaction was completed, the sample was washed three times with deionized water, placed on a clean petri dish, and dried in a vacuum oven at 40°C. This completed the modification of the polymer adhesion layer on the three-dimensional pyramidal polydimethylsiloxane (PDMS) substrate.
[0065] Step 3: Immerse the polydimethylsiloxane (PDMS) substrate modified with the polymer adhesion layer obtained in Step 2 into 10 mmol / L ammonium tetrachloropalladate for 30 minutes. After sufficient ion exchange, the polymer adhesion layer adsorbs tetrachloropalladate ions. Then, rinse with plenty of deionized water to remove the unadsorbed tetrachloropalladate ions. Finally, immerse the polydimethylsiloxane (PDMS) substrate with adsorbed tetrachloropalladate ions into... 63 A three-dimensional β-ray emission source with high emissivity was obtained by depositing Ni in a chemical plating solution at 25°C for 6 hours.
[0066] See Figure 5 The deposited in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The Ni metal layer has a thickness of 2 μm.
[0067] In step 1, the area of a single graphic in the patterned rectangular matrix array is 100um × 100um.
[0068] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1. The pretreatment process is to degas the mixture for 30 minutes.
[0069] See Figure 6 In step 3 63 The average sheet resistance of the Ni metal layer is 1 Ω / sq.
[0070] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of nickel sulfate-63 hexahydrate (0.1 mol / L), sodium citrate (0.1 mol / L), and lactic acid (0.1 mol / L); solution B is composed of dimethylamine borane with a concentration of 10 mol / L. Each time... 63 During Ni electroless deposition, solution A and solution B were mixed at a volume ratio of 100:1, and the pH was adjusted to 9 with ammonia. Deposition was carried out at 40°C for 15 hours to obtain a three-dimensional β-ray emission source with high emissivity.
[0071] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0072] Example 4
[0073] See Figure 1 A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between the molecules and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0074] The flexible substrate is polyurethane, and the polymer adhesive layer is polyethyleneimine.
[0075] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0076] Step 1, using photolithography and wet etching on <100> Patterned rectangular matrix arrays were fabricated on the surface of a p-type silicon wafer. Then, the exposed silicon dioxide (SiO2) pattern on the wafer surface was etched using a hydrofluoric acid (HF) buffer solution, effectively removing the surface SiO2 passivation layer. After drying at 85°C, the wafer was transferred to a mixed solution of isopropanol and potassium hydroxide for anisotropic etching for 4.5 hours, thus fabricating a silicon mold with a micro-pyramid structure. The mass ratio of isopropanol to potassium hydroxide was 1:4. The remaining SiO2 layer on the surface of the silicon mold was etched using a hydrofluoric acid (HF) buffer solution to obtain a reusable silicon mold. The pretreated mixture was spin-coated onto the reusable silicon mold and cured at 85°C for 4.5 hours to obtain a polyurethane film. The polyurethane or polystyrene-polyisoprene-polystyrene film was peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on the surface. See also... Figure 2 (a) shows a substrate with a periodic three-dimensional pyramid structure;
[0077] Step 2: Place the polyurethane substrate with a three-dimensional pyramidal structure obtained in Step 1 onto a substrate containing tannic acid (50 mg / mL) and polyethyleneimine (weight-average molecular weight M). w The reaction was carried out in a 50 mM Tris buffer solution (60000, 0.5 mg / mL) for 20 hours. After the reaction was completed, the mixture was washed three times with deionized water, placed on a clean petri dish, and dried in a vacuum oven at 40°C. This completed the modification of the polymer adhesion layer on the polyurethane substrate with the three-dimensional pyramid structure.
[0078] Step 3: Immerse the polyurethane substrate modified with the polymer adhesion layer obtained in Step 2 in 50 mmol / L ammonium tetrachloropalladate for 50 minutes. After a thorough ion exchange process, the polymer adhesion layer adsorbs tetrachloropalladate ions. Then, rinse with plenty of deionized water to remove any unadsorbed tetrachloropalladate ions. Finally, immerse the polyurethane substrate with adsorbed tetrachloropalladate ions in... 63 A three-dimensional β-ray emission source with high emissivity was obtained by depositing Ni in a chemical plating solution at 25°C for 1 hour.
[0079] See Figure 2 The deposited in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The Ni metal layer has a thickness of 1 μm.
[0080] In step 1, the area of a single graphic in the patterned rectangular matrix array is 150um × 150um.
[0081] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1. The pretreatment process is to degas the mixture for 30 minutes.
[0082] See Figure 3 In step 3 63 The average sheet resistance of the Ni metal layer is 0.377 Ω / sq.
[0083] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of nickel sulfate-63 hexahydrate (0.8 mol / L), sodium citrate (0.8 mol / L), and lactic acid (0.8 mol / L); solution B is composed of dimethylamine borane with a concentration of 8 mol / L. Each time... 63 For Ni electroless deposition, solution A and solution B are mixed in a 1:1 volume ratio, and then the pH is adjusted to 9 with ammonia. Deposition is carried out at 45°C for 22 hours.
[0084] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0085] Example 5
[0086] See Figure 1 A high-emissivity three-dimensional beta-ray emission source includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between the molecules and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
[0087] The flexible substrate is polystyrene-polyisoprene-polystyrene, and the polymer adhesive layer is polyethyleneimine.
[0088] A method for preparing a three-dimensional β-ray emission source with high emissivity includes the following steps:
[0089] Step 1, using photolithography and wet etching on <100> Patterned rectangular matrix arrays were fabricated on the surface of a p-type silicon wafer. Then, the exposed silicon dioxide (SiO2) pattern on the wafer surface was etched using a hydrofluoric acid (HF) buffer solution, effectively removing the surface SiO2 passivation layer. After drying at 65°C, the wafer was transferred to a mixed solution of isopropanol and potassium hydroxide for anisotropic etching for 2.5 hours, thus fabricating a silicon mold with a micro-pyramid structure. The mass ratio of isopropanol to potassium hydroxide was 1:1. The remaining SiO2 layer on the surface of the silicon mold was etched using a hydrofluoric acid (HF) buffer solution to obtain a reusable silicon mold. The pretreated mixture was spin-coated onto the reusable silicon mold and cured at 87°C for 2.5 hours to obtain a polystyrene-polyisoprene-polystyrene film. The polystyrene-polyisoprene-polystyrene film was peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on its surface. See also... Figure 2 (a) shows a substrate with a periodic three-dimensional pyramid structure;
[0090] Step 2: Place the polystyrene-polyisoprene-polystyrene substrate with a three-dimensional pyramidal surface obtained in Step 1 onto a substrate containing tannic acid (1 mg / mL) and polyethyleneimine (weight-average molecular weight M). w The reaction was carried out in a 1mM (10000, 0.1 mg / mL) Tris buffer solution for 2 hours. After the reaction was completed, the mixture was washed three times with deionized water, placed on a clean petri dish, and dried in a vacuum oven at 40°C. This completed the modification of the polymer adhesion layer on the polystyrene-polyisoprene-polystyrene substrate with a three-dimensional pyramid structure.
[0091] Step 3: Immerse the polystyrene-polyisoprene-polystyrene substrate modified with the polymer adhesion layer obtained in Step 2 into 1 mmol / L ammonium tetrachloropalladate solution for 8 minutes. After a thorough ion exchange process, the polymer adhesion layer adsorbs tetrachloropalladate ions. Then, rinse with plenty of deionized water to remove any unadsorbed tetrachloropalladate ions. Finally, immerse the polystyrene-polyisoprene-polystyrene substrate with adsorbed tetrachloropalladate ions into... 63 A three-dimensional β-ray emission source with high emissivity was obtained by depositing Ni in a chemical plating solution at 25°C for 1 hour.
[0092] See Figure 2 The deposited in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The Ni metal layer has a thickness of 0.5 μm.
[0093] In step 1, the area of a single graphic in the patterned rectangular matrix array is 180um × 180um.
[0094] The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1. The pretreatment process is to degas the mixture for 30 minutes.
[0095] See Figure 3 In step 3 63 The average sheet resistance of the Ni metal layer is 0.57 Ω / sq.
[0096] The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of nickel sulfate-63 hexahydrate (0.5 mol / L), sodium citrate (0.5 mol / L), and lactic acid (0.5 mol / L); solution B is composed of dimethylamine borane with a concentration of 9 mol / L. Each time... 63 For Ni electrodeposition, solution A and solution B are mixed at a volume ratio of 20:1, and then the pH is adjusted to 9 with ammonia. Deposition is carried out at 50°C for 23 hours.
[0097] An application of a high-emissivity three-dimensional beta-ray emission source for mounting on the surface of a miniature beta cell converter, utilizing a three-dimensional structure. 63 The Ni metal layer decays continuously, emitting beta rays.
[0098] As can be seen from the embodiments, the present invention uses room temperature electroless deposition technology to deposit on the surface of a flexible substrate with a three-dimensional structure. 63 A Ni metal β-radiative source layer can be achieved by controlling the deposition time. 63 The Ni metal layer thickness can be controllably prepared within the range of 0.1-2 μm; and 63 The average sheet resistance of the Ni metal layer is 0.1-1Ω / sq. It overcomes the complex process of traditional metal thin film deposition technology, is not limited by the substrate material and surface morphology, and has high adhesion to the substrate. It has the characteristics of low output power, high energy conversion efficiency, high energy density, and suitability for micro-devices and thicker radiation sources. It also has the advantages of high raw material utilization, wide application scenarios, and low reaction temperature.
Claims
1. A method for preparing a three-dimensional β-ray emission source with high emissivity, characterized in that, Includes the following steps: Step 1, using photolithography and wet etching on <100> Patterned rectangular matrix arrays are prepared on the surface of p-type silicon wafers. Then, the exposed silicon dioxide (SiO2) pattern on the silicon wafer surface is etched with hydrofluoric acid (HF) buffer solution. After drying at 60-90 °C, it is transferred to a mixed solution of isopropanol and potassium hydroxide for anisotropic etching for 2-5 hours to obtain a silicon mold with a micro pyramid structure. The mass ratio of isopropanol to potassium hydroxide is (1-3):(2-4). The remaining SiO2 layer on the surface of the silicon mold is etched with hydrofluoric acid (HF) buffer solution to obtain a reusable silicon mold. The pretreated mixture is spin-coated onto the reusable silicon mold and cured at 75-90 °C for 2-5 hours to obtain a polydimethylsiloxane (PDMS) film. The PDMS film is peeled off from the silicon mold to obtain a substrate with a three-dimensional pyramid structure on the surface. Step 2: Modify a polymer adhesion layer onto the substrate with a three-dimensional pyramid structure obtained in Step 1. Immerse the substrate with the three-dimensional pyramid structure in a solution containing one or more of the following at a mass concentration of 0.1-100 mg / ml: tannic acid, lignin, fumaric acid, and malic acid, and polyethyleneimine (weight average molecular weight M). w =600-70000, 0.01-1 mg / mL) reacted in Tris buffer solution (0.1-100 mM) for 1-24 h, followed by washing and drying; Step 3: Immerse the substrate modified with the polymer adhesion layer obtained in Step 2 in the catalyst for 5-60 minutes, rinse with deionized water, and then place it in a solution containing... 63 Electroless deposition of a polymer adhesion layer is performed on the substrate surface in a Ni metal ion salt electroless plating solution at room temperature. 63 A Ni metal layer was used to obtain a three-dimensional β-ray emission source with high emissivity. The polymeric adhesive layer is polyethyleneimine; The polydimethylsiloxane (PDMS) may be replaced by polyurethane or polystyrene-polyisoprene-polystyrene.
2. The method for preparing a three-dimensional β-ray emission source with high emissivity according to claim 1, characterized in that, The pretreated mixture in step 1 is a mixture of polydimethylsiloxane (PDMS) matrix and curing agent with a mass ratio of 10:1; the pretreatment process is to degas the mixture for 30-90 minutes. The polydimethylsiloxane (PDMS) may be replaced by polyurethane or polystyrene-polyisoprene-polystyrene.
3. The method for preparing a three-dimensional β-ray emission source with high emissivity according to claim 1, characterized in that, In step 1, the area of a single graphic in the patterned rectangular matrix array ranges from 5 μm × 5 μm to 200 μm × 200 μm.
4. The method for preparing a three-dimensional β-ray emission source with high emissivity according to claim 1, characterized in that, The deposition in step 3 63 The Ni metal layer is composed of 63 Ni nanoparticles are densely packed together. 63 The thickness of the Ni metal layer is 0.1-2 μm; 63 The average sheet resistance of the Ni metal layer is 0.1-1 Ω / sq.
5. The method for preparing a three-dimensional β-ray emission source with high emissivity according to claim 1, characterized in that, In step 3, the catalyst is an ammonium tetrachloropalladium solution with a concentration of 0.01-100 mmol / L.
6. The method for preparing a three-dimensional β-ray emission source with high emissivity according to claim 1, characterized in that, The chemical plating solution in step 3 is a mixture of solution A and solution B. Solution A is a mixture of one of nickel sulfate-63 hexahydrate, nickel chloride-63 hexahydrate, or nickel nitrate-63 hexahydrate (0.01-1 mol / L), sodium citrate (0.01-1 mol / L), and lactic acid (0.01-1 mol / L). Solution B is dimethylamine borane with a concentration of 0.01-10 mol / L. 63 When electroless Ni deposition is performed, solution A and solution B are mixed at a volume ratio of (1-100):1, and then the pH is adjusted to 7-10 with ammonia. Deposition is carried out at 25-50 °C for 1-24 h.
7. A three-dimensional β-ray emission source with high emissivity prepared by any one of claims 1 to 6, characterized in that, This includes a flexible substrate with a three-dimensional pyramid structure, the surface of which is modified with a polymer adhesion layer. The polymer adhesion layer binds the metal particles through molecular interactions between molecular functional groups and the metal particles. 63 Ni particles are adsorbed on the surface of the flexible substrate.
8. A three-dimensional β-ray emission source with high emissivity according to claim 7, characterized in that, The flexible substrate is made of polydimethylsiloxane (PDMS), polyurethane, or polystyrene-polyisoprene-polystyrene.
9. A three-dimensional β-ray emission source with high emissivity according to claim 7, characterized in that, The polymer adhesive layer is polyethyleneimine.
10. An application of a three-dimensional β-ray emission source with high emissivity, characterized in that, For mounting on the surface of a miniature beta battery converter, via a three-dimensional structure 63 The Ni metal layer decays continuously, emitting beta rays.