Preparation method of energy conversion device and preparation method of isotope battery

Abstract

The invention relates to the technical field of isotope batteries and discloses a preparation method of a transducer device and a preparation method of an isotope battery, the preparation method of the transducer device comprises the following steps: S1, preparing a to-be-fragile layer on the surface of a soluble substrate, the to-be-fragile layer comprising solvent atoms; s2, preparing a first solute layer on the surface of the layer to be fragile; s3, heating at least one of the soluble substrate, the to-be-fragile layer and the first solute layer; s4, a, etching is carried out on the surface of the fragile layer; and S5, a transducer device is prepared on the surface, with the preset shape, of the fragile layer. According to the preparation method of the transducer device, the technical problems of how to prepare the transducer device with effective thickness, realizing large-scale three-dimensional structure preparation on the surface of the transducer device and uniformly loading a radioactive source on the surface of the three-dimensional structure can be solved, the transducer device can be prepared on the fragile layer, and the radioactive source can be uniformly loaded on the surface of the three-dimensional structure by utilizing the pulverization property of the fragile layer. Therefore, a substrate-free energy conversion device can be obtained, and the effective radiation receiving area of the energy conversion device can be increased.

Description

Technical Field

[0001] This invention relates to the field of isotope battery technology, specifically to a method for preparing a transducer and an isotope battery. Background Technology

[0002] Since the discovery of radiation in the early 20th century, researchers have dedicated themselves to developing radioisotope batteries for use in demanding environments. For a long time, isotope batteries have been considered the optimal choice for long-life, miniature power sources in many critical fields. Their main working principle is the conversion of the decay energy of radioactive elements into electrical energy. In other words, by utilizing the decay characteristics of radioactive elements, isotope batteries possess advantages such as long service life and high energy density, while also exhibiting strong environmental adaptability and requiring no human intervention. They have broad application prospects in military defense, aerospace, deep-sea and polar regions, biomedicine, and microcomputer systems.

[0003] An isotope battery is a device that converts the energy of energy-carrying particles (alpha particles, beta particles, gamma rays) released during the decay of radioactive isotopes into electrical energy. Based on the type of radioactive source, they can be classified into alpha-type, beta-type, and gamma-type isotope batteries. Among them, beta-type isotope batteries have received widespread attention due to their advantages such as high energy density, low damage to transducers, moderate decay period, and low external radiation. Beta-type isotope batteries convert the energy of beta particles released during the radioactive source's decay into electrical energy using semiconductor transducers. The structure of these semiconductor transducers is generally a PN junction, PiN junction, or Schottky diode. When the isotope source irradiates the semiconductor transducer, a large number of electron-hole pairs are generated inside the transducer under ionization and excitation. The depletion region has a strong built-in electric field that separates these electron-hole pairs. Electron-hole pairs generated in or diffusing into the depletion region are separated and move in different directions. Before recombination, they reach the two electrodes, forming a radiative current.

[0004] The two core components of a beta-isotope battery are the isotope source and the semiconductor transducer. The battery's energy originates from the decay energy of the isotope source, making the selection of a suitable source crucial. Tritium sources, with their moderate cost, low energy content (making them less prone to damage), and long half-life, are a preferred choice for the radioactive source in beta-isotope batteries. Tritium is gaseous at room temperature and is typically adsorbed onto solids. Currently, the main adsorbent materials include titanium, zirconium, vanadium, and zirconium-cobalt. Among these, metallic Ti has a theoretical H / Ti ratio of 2 and is currently the element with the highest hydrogen storage density in nature. However, it is highly susceptible to oxygen contamination in air, causing its hydrogen storage capacity to decrease exponentially. Therefore, a complex activation process is required during adsorption. Furthermore, continuous technological advancements have led to higher demands for output power—specifically, higher power output with a constant volume. Improving the hydrogen storage performance of materials is a highly effective method in this regard. Secondly, there's the issue of transducers. Theoretically, a larger bandgap leads to higher energy conversion efficiency. Silicon carbide (SiC), gallium arsenide (GaAs), gallium nitride (GaN), and diamond have all been successfully applied to β-type isotope batteries with significant success. However, transducers can only be grown on specific materials, which necessitates the introduction of a substrate during isotope battery fabrication. For example, the silicon substrate used in patent CN102543239B is 400 micrometers thick. The penetration depth of β particles decaying from the radioactive source in the transducer within the transducer is only 1-5 μm. The remaining substrate thickness is redundant, meaning the isotope battery is larger, resulting in limited power output improvement for the same volume and significantly restricting its application range. To improve the output power of isotope solar cells, a three-dimensional loading technique has been proposed to process the transducer. By increasing the contact area between the source and the transducer, more β particles can enter the transducer. For example, patent CN112086217B proposes to use an etching process to prepare circular hole structures with a thickness of 1-1000 micrometers on the surface of a silicon carbide substrate, and then deposit tritium storage material on the inner wall of the hole. However, this approach has the following problems: 1. The etching process for holes on the silicon carbide surface is complex and technically demanding, and silicon carbide devices are expensive, making them unsuitable for mass production. 2. After etching such a deep circular hole structure, higher technical requirements are placed on the deposition of tritium storage material on the inner wall of the hole. Inhomogeneous deposition of the material is very likely to occur, causing the material to crack and peel off due to stress concentration during tritium storage, ultimately leading to the failure of the isotope solar cell.

[0005] In related technologies, how to prepare transducers with effective thickness, how to prepare large-scale three-dimensional structures on the surface of transducers, and how to uniformly load radiation sources onto the surface of three-dimensional structures are technical problems that urgently need to be solved in this field. Summary of the Invention

[0006] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for fabricating a transducer. This method involves fabricating the transducer on a fragile layer, and then utilizing the pulverizable property of the fragile layer to obtain a substrate-free transducer. Simultaneously, by etching a predetermined shape onto the surface of the fragile layer, the transducer formed on the fragile layer also possesses a structure similar to the predetermined shape. This structure can increase the effective radiation-receiving area of ​​the transducer. In other words, within a limited space, the predetermined shape can increase the effective radiation-receiving area of ​​the transducer, i.e., it can increase the contact area between the isotope source and the transducer, allowing more β-ions to enter the transducer, thereby significantly improving the output power of the isotope cell.

[0007] The method for fabricating the transducer of the present invention includes:

[0008] S1: Prepare a fragile layer on the surface of a soluble substrate, the fragile layer comprising solvent atoms;

[0009] S2: Prepare a first solute layer on the surface of the layer to be fragile, the first solute layer comprising solute atoms soluble in the layer to be fragile;

[0010] S3: Heating at least one of the soluble substrate, the fragile layer to be broken, and the first solute layer, causing the solute atoms in the first solute layer to migrate to the fragile layer to be broken, thereby generating a fragile layer in the fragile layer;

[0011] S4: a. Etch the surface of the fragile layer to generate a preset shape;

[0012] b. Prepare a second solute layer on the surface of the fragile layer, the second solute layer comprising solute atoms soluble in the fragile layer;

[0013] c. Dissolve the soluble substrate using a substrate solvent;

[0014] In this case, at least one of a and b is located after c in chronological order, and the position of the second solute layer is opposite to the position of the preset shape on both sides of the fragile layer;

[0015] S5: Prepare a transducer on the surface of the fragile layer having the preset shape;

[0016] S6: Heat at least one of the transducer, the fragile layer, and the second solute layer, and the solute atoms in the second solute layer migrate to the fragile layer, causing the fragile layer to pulverize, thereby obtaining the transducer.

[0017] Optionally, after S4 and before S5, the method for fabricating the transducer further includes: fabricating a transducer substrate on the surface of the fragile layer having the preset shape, and then fabricating the transducer device on the transducer substrate;

[0018] The transducer substrate is made of the same material as the transducer device.

[0019] Optionally, the material of the transducer substrate is silicon carbide; and / or

[0020] The thickness of the transducer substrate is 1 μm to 10 μm.

[0021] Optionally, the transducer is made of silicon carbide.

[0022] Optionally, the preset shape is wavy.

[0023] Optionally, the ratio of the outer convex diameter of the wave-shaped shape to the inner concave diameter of the wave-shaped shape is (0.5-1):(1-2).

[0024] Optionally, the soluble substrate is made of at least one of sodium chloride, potassium iodide, and sodium iodide; and / or

[0025] The surface finish of the soluble substrate is greater than 0.6.

[0026] Optionally, the substrate solvent is water.

[0027] Optionally, the material of the fragile layer is silicon; and / or

[0028] The thickness of the fragile layer is 1 μm to 5 μm; and / or

[0029] The material of the first solute layer is lithium; and / or

[0030] The thickness of the first solute layer is 1 μm to 2 μm; and / or

[0031] The material of the second solute layer is lithium; and / or

[0032] The thickness of the second solute layer is 1 μm to 2 μm.

[0033] Optionally, the method for preparing the isotope battery includes the method for preparing the transducer described above. Attached Figure Description

[0034] Figure 1 This is a schematic flowchart illustrating the fabrication method of the transducer device according to a specific embodiment of the present invention.

[0035] Figure reference numerals: 1-Soluble substrate, 2-Fragile layer to be formed, 3-First solute layer, 4-Fragile layer, 41-Preset shape, 5-Second solute layer, 6-Transducer device, 61-First doped semiconductor, 62-Second doped semiconductor, 7-Transducer substrate, 8-Isotope source. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The fabrication method of the transducer device according to an embodiment of the present invention is described below with reference to the accompanying drawings. Figure 1 As shown, the method for fabricating the transducer device according to an embodiment of the present invention includes:

[0038] S1: Prepare a fragile layer 2 on the surface of a soluble substrate 1. The fragile layer 2 includes solvent atoms.

[0039] S2: Prepare a first solute layer 3 on the surface of the fragile layer 2, the first solute layer 3 comprising solute atoms soluble in the fragile layer 2;

[0040] S3: Heating at least one of the soluble substrate 1, the fragile layer 2 and the first solute layer 3, solute atoms in the first solute layer 3 migrate to the fragile layer 2, causing the fragile layer 2 to generate a fragile layer 4.

[0041] S4: a. Etch on the surface of the fragile layer 4 to generate a preset shape 41;

[0042] b. Prepare a second solute layer 5 on the surface of the fragile layer 4, the second solute layer comprising solute atoms soluble in the fragile layer 4;

[0043] c. Dissolve the soluble substrate 1 using a substrate solvent;

[0044] In this case, at least one of a and b is located after c in the execution order, and the position of the second solute layer 5 is opposite to the position of the preset shape 41 on both sides of the fragile layer 4.

[0045] S5: Prepare a transducer 6 on the surface of the fragile layer 4 with a predetermined shape 41;

[0046] S6: Heat at least one of the transducer 6, the fragile layer 4, and the second solute layer 5, and the solute atoms in the second solute layer 5 migrate to the fragile layer 4, causing the fragile layer 4 to pulverize, thus obtaining the transducer 6.

[0047] According to a specific embodiment of the present invention, a transducer device 6 is fabricated on a fragile layer 4, and by utilizing the pulverizable property of the fragile layer 4, a substrate-free transducer device 6 can be obtained. Simultaneously, by etching a predetermined shape 41 onto the surface of the fragile layer 4, the transducer device 6 formed on the fragile layer 4 also has a structure similar to the predetermined shape 41. This structure can increase the effective radiation-receiving area of ​​the transducer device 6. In other words, within a defined space, the predetermined shape 41 can increase the effective radiation-receiving area of ​​the transducer device 6, i.e., increase the contact area between the isotope source and the transducer device 6, allowing more β ions to enter the transducer device 6, thereby significantly improving the output power of the isotope cell.

[0048] like Figure 1 As shown, in order to make the technical solution of this application easier to understand, the technical solution of this application will be described in more detail below with specific embodiments of the transducer fabrication method.

[0049] The method for fabricating the transducer device according to embodiments of the present invention includes:

[0050] S1: A fragile layer 2, comprising solvent atoms, is prepared on the surface of a soluble substrate 1. Specifically, to prepare a fragile layer 2 of the required thickness, it must be prepared on a substrate. That is, in the prior art, a micrometer-thick fragile layer 2 cannot be generated independently; only by preparing it on a substrate can a micrometer-thick fragile layer 2 be obtained. Simultaneously, by selecting a substrate that can detach from the fragile layer 2 before preparing it, a separate fragile layer 2 can be obtained. That is, the two opposing surfaces of the separate fragile layer 2 are used in subsequent steps to prepare other functional layers. This can be understood as follows: in subsequent steps, both surfaces of the fragile layer 2 need to be used to prepare other functional layers; by selecting a soluble substrate 1 as the substrate for the fragile layer 2, the soluble substrate 1 must detach from the fragile layer 2 for subsequent steps to be executed.

[0051] In some specific embodiments, the material of the soluble substrate 1 is at least one of sodium chloride, potassium iodide, and sodium iodide. Specifically, sodium chloride, potassium iodide, and sodium iodide all have high solubility in aqueous solutions, which facilitates the detachment of the soluble substrate 1 from the fragile layer 2.

[0052] In some specific embodiments, the surface finish of the soluble substrate 1 is greater than 0.6. Specifically, the greater the surface finish of the soluble substrate 1, the smaller its surface roughness, which allows the coating atoms to bond tightly with the soluble substrate 1, thereby improving the adhesion of the prepared coating.

[0053] In some specific embodiments, the substrate solvent is water.

[0054] In some specific embodiments, the material of the fragile layer 2 is silicon. Specifically, during the diffusion of lithium atoms into the silicon, the fragile layer 2 undergoes significant volume expansion and contraction.

[0055] In some specific embodiments, the thickness of the fragile layer 2 is 1 μm to 5 μm. Specifically, after the fragile layer 4 is subsequently formed from the fragile layer 2, the 1 μm to 5 μm fragile layer 4 is more prone to pulverization during the diffusion of lithium metal atoms into silicon.

[0056] In some specific embodiments, the fragile layer 2 can be prepared by DC magnetron sputtering, radio frequency magnetron sputtering, electron beam deposition, electrochemical deposition, chemical deposition, etc.

[0057] It should be noted that the solvent atoms are made of at least one of silicon, germanium, and tin.

[0058] S2: A first solute layer 3 is prepared on the surface of the fragile layer 2. The first solute layer 3 includes solute atoms soluble in the fragile layer 2. Specifically, the first solute layer 3 is prepared on the fragile layer 2, and the solute atoms in the first solute layer 3 can migrate into the fragile layer 2, causing the fragile layer 2 to expand and contract. After the fragile layer 2 can form a fragile layer 4, the internal structure of the fragile layer 4 becomes loose, thereby reducing the pulverization requirement of the fragile layer 4.

[0059] In some specific embodiments, the first solute layer 3 is made of lithium. Specifically, lithium has a small atomic radius and requires little driving force for diffusion, allowing a single silicon atom to bond with a dozen or even dozens of lithium atoms.

[0060] In some specific embodiments, the thickness of the first solute layer 3 is 1 μm to 2 μm. Specifically, the 1 μm to 2 μm first solute layer 3 can completely diffuse into the fragile layer 2, thereby changing the internal structure of the fragile layer 2.

[0061] In some specific embodiments, the preparation of the first solute layer 3 can be carried out by DC magnetron sputtering, radio frequency magnetron sputtering, electron beam deposition, electrochemical deposition, and chemical deposition.

[0062] It should be noted that the solute atom corresponds to the solvent atom.

[0063] S3: Heating at least one of the soluble substrate 1, the fragile layer 2, and the first solute layer 3 causes solute atoms in the first solute layer 3 to migrate towards the fragile layer 2, resulting in the formation of a fragile layer 4 in the fragile layer 2. Specifically, heating at least one of the soluble substrate 1, the fragile layer 2, and the first solute layer 3 can accelerate the diffusion of solute atoms into the fragile layer 2, causing the fragile layer 2 to expand, thereby generating a fragile layer 4 in the fragile layer 2.

[0064] In some specific embodiments, at least one of the soluble substrate 1, the fragile layer 2, and the first solute layer 3 is heated, wherein the heating temperature is in the range of 100°C to 200°C, and the diffusion rate of lithium atoms in silicon is relatively fast. Furthermore, within the range of 100°C to 200°C, the diffusion depth of lithium atoms and their concentration distribution in silicon can be controlled.

[0065] S4: a. Etch on the surface of the fragile layer 4 to generate a preset shape 41;

[0066] b. Prepare a second solute layer 5 on the surface of the fragile layer 4, the second solute layer comprising solute atoms soluble in the fragile layer 4;

[0067] c. Dissolve the soluble substrate 1 using a substrate solvent;

[0068] In this case, at least one of a and b is located after c in the execution order, and the position of the second solute layer 5 is located opposite to the position of the preset shape 41 on both sides of the fragile layer 4.

[0069] In some specific embodiments, etching is performed on the surface of the fragile layer 4 to generate a predetermined shape 41. Specifically, generating the predetermined shape 41 on the surface of the fragile layer 4 allows the transducer 6 fabricated on the fragile layer 4 to also have a shape similar to the predetermined shape 41, thereby increasing the surface area of ​​the transducer 6, that is, increasing the area of ​​the transducer 6 that receives radiation. In other words, within a limited space, the predetermined shape 41 can increase the area of ​​the transducer 6 that receives radiation, that is, increase the contact area between the isotope source and the transducer 6, allowing more β ions to enter the transducer 6, thereby significantly improving the output power of the isotope battery. The transducer 6 includes a first doped semiconductor 61 and a first doped semiconductor 62.

[0070] In some specific embodiments, etching of the surface of the fragile layer 4 can be performed using ion beam etching, reactive etching, and electron beam etching.

[0071] In some specific embodiments, the preset shape 41 is wavy. Specifically, within the same space, the wavy structure can increase the contact area between the isotope source and the transducer, thereby increasing the output power of the isotope source.

[0072] In some specific embodiments, the ratio of the convex outer diameter to the concave inner diameter of the wavy shape is (0.5-1):(1-2). Specifically, a ratio of (0.5-1):(1-2) for the convex outer diameter and the concave inner diameter allows for uniform deposition of the tritium storage film (isotope source). Furthermore, the deposition of the film in the concave inner diameter structure has a stress-dispersing effect. For example, when a titanium film absorbs hydrogen, it undergoes significant expansion with increasing hydrogen content. When the ratio of hydrogen atoms to titanium atoms reaches 1.5, the expansion rate of the titanium film reaches as high as 22.2%. The wavy structure can disperse the stress of the titanium film during its expansion, preventing damage to the transducer 6. It should be noted that the coefficient of thermal expansion of titanium is much higher than that of the substrate. During hydrogen absorption, the expansion stress of the titanium film mainly acts on the substrate. When calculating the force on the substrate, the formula is F=σ×A, where σ is the expansion stress of titanium and A is the area of ​​the substrate subjected to the force. On the same substrate, the larger the area of ​​a region subjected to force, the greater the force experienced by that region. During the expansion process of the titanium film in the concave region, the forces acting in all directions have the same reaction force, which can effectively counteract the force exerted by the titanium film on the substrate during the expansion process. The convex region, on the other hand, needs to have a certain arc-shaped structure to avoid stress concentration during the expansion of the titanium film. Therefore, when preparing a corrugated substrate, the diameter of the concave region is larger than that of the convex region. Preferably, the ratio of the diameter of the convex region to the diameter of the concave region is 1 / 2, thereby introducing an arc structure into the concave region while obtaining the maximum stress counteraction in the concave region.

[0073] In some specific embodiments, a second solute layer 5 is prepared on the surface of the fragile layer 4. The second solute layer includes solute atoms soluble in the fragile layer 4. Specifically, the second solute layer 5 is prepared on the fragile layer 4, and the solute atoms in the second solute layer 5 can migrate into the fragile layer 4. The second solute layer 5 can act as a driving force to provide solute atoms in the fragile layer 4. Utilizing the concentration difference of solute atoms in the fragile layer 4, solute atoms can continuously diffuse into the fragile layer 4, causing internal cyclic expansion and contraction, further pulverizing the fragile layer 4.

[0074] In some specific embodiments, the material of the second solute layer 5 is lithium. The material of the second solute layer 5 is the same as that of the first solute layer 3, and its function and principle are similar, so it will not be described again here.

[0075] In some specific embodiments, the thickness of the second solute layer 5 is 1 μm to 2 μm. Specifically, the second solute layer 5 has the same thickness as the first solute layer 3, thereby achieving a sufficiently long diffusion depth in the fragile layer 4 and increasing the number of cyclic expansion and contraction cycles.

[0076] In some specific embodiments, the second solute layer 5 can be prepared by flux magnetron sputtering, radio frequency magnetron sputtering, electron beam deposition, electrochemical deposition, and chemical deposition.

[0077] In some specific embodiments, the soluble substrate 1 is dissolved using a substrate solvent. Specifically, the soluble substrate 1 is dissolved using a substrate solvent, causing the soluble substrate 1 to completely detach from the fragile layer 4.

[0078] It should be noted that at least one of a and b must be executed after c. Execution step a or b must follow execution step c, or both execution steps a and b must follow execution step c. Execution step c can remove the soluble substrate 1 on the fragile layer 4, allowing execution steps a or b to be performed on the fragile layer 4.

[0079] S5: A transducer 6 is fabricated on the surface of the fragile layer 4 with a predetermined shape 41. Specifically, after the transducer 6 is fabricated, the surface shape or the overall shape of the transducer 6 is similar to the predetermined shape 41, thereby increasing the radiation receiving area of ​​the transducer 6. That is, the contact area between the isotope source and the transducer 6 can be increased, allowing more β ions to enter the transducer 6, which can significantly improve the output power of the isotope battery.

[0080] In some specific embodiments, the transducer 6 is made of silicon carbide.

[0081] In some specific embodiments, the thickness of the transducer 6 is 1 μm to 3 μm.

[0082] In some specific embodiments, the transducer 6 can be fabricated using chemical vapor deposition, vapor deposition, or molecular beam epitaxy.

[0083] S6: Heating at least one of the transducer 6, the fragile layer 4, and the second solute layer 5 causes solute atoms in the second solute layer 5 to migrate into the fragile layer 4, resulting in the pulverization of the fragile layer 4 and thus obtaining the transducer 6. Specifically, heating at least one of the transducer 6, the fragile layer 4, and the second solute layer 5 can accelerate the diffusion of solute atoms into the fragile layer 4, causing the fragile layer 4 to expand. In other words, solute atoms (lithium) and silicon atoms in the fragile layer 4 can combine to form compounds with different ratios at different temperatures and concentrations, thereby causing the fragile layer 4 to undergo significant expansion and contraction, ultimately leading to the pulverization of the fragile layer 4 and obtaining the substrate-free transducer 6.

[0084] In some specific embodiments, after S4 and before S5, the fabrication method of the transducer 6 further includes: fabricating a transducer substrate 7 on the surface of the fragile layer 4 having a predetermined shape 41, and then fabricating the transducer 6 on the transducer substrate 7. The material used to fabricate the transducer substrate 7 is the same as that used to fabricate the transducer 6. When the transducer is silicon carbide, it must be homogeneously grown on the surface of the silicon carbide epitaxial layer, i.e., the transducer substrate 7, because silicon carbide wafers have high internal impurities when used as substrates, affecting electrical performance; secondly, the fabrication is difficult and the doping effect is poor. Heterogeneous epitaxial growth on a silicon substrate surface can only yield cubic silicon carbide, not hexagonal silicon carbide, and the device cannot operate at high temperatures, high power, and high voltage.

[0085] In some specific embodiments, the thickness of the transducer substrate 7 is from 1 μm to 10 μm. In some specific embodiments, the transducer substrate 7 can be fabricated using 3D printing technology or thermal evaporation technology.

[0086] In some specific embodiments, the transducer substrate 7 is made of silicon carbide.

[0087] Another specific embodiment of the present invention provides a method for preparing an isotope battery, which includes the above-described method for preparing a transducer.

[0088] In some specific embodiments, the method for preparing the isotope battery further includes: preparing an isotope source 8 on the transducer 6.

[0089] In some specific embodiments, the isotope source material is TiZrVABC, and isotope source 8 is also doped with 0.1% to 1% yttrium. Adding yttrium to the alloy enables competitive oxidation. Oxygen diffusion preferentially enters the alloy interior from the grain boundaries, and the 0.1% to 1% yttrium content can reduce the oxidation degree of other elements within the alloy without affecting the overall alloy performance. A can be the first among iron, niobium, palladium, hafnium, nickel, and cobalt; B can be the second among iron, niobium, palladium, hafnium, nickel, and cobalt; and C can be the third among iron, niobium, palladium, hafnium, nickel, and cobalt. Titanium accounts for 20% to 40% of the composition. As the elemental metal with the highest hydrogen storage capacity in nature, titanium constitutes the largest proportion in the alloy, playing a role in increasing the alloy's hydrogen storage capacity. Zirconium accounts for 20% to 30% of the composition. Zirconium improves the alloy's thermal stability; compared to the 200°C operating temperature of titanium hydride, zirconium hydride does not decompose at 300°C. Vanadium comprises 10% to 20% of the alloy. Vanadium has a dispersion catalytic effect, which can refine grains and increase the number of grain boundaries, thereby improving the hydrogen absorption performance of the alloy. Element A comprises 5% to 10%, Element B comprises 5% to 10%, and Element C comprises 5% to 10%. To meet the requirements of high-entropy alloys, the proportions of elements A, B, and C should be higher than 5%. At the same time, the addition of elements with different atomic diameters can increase the interatomic gaps in the alloy, so that not only are compounds that combine with hydrogen formed in the alloy, but there are also more interstitial spaces to store hydrogen, thereby increasing the hydrogen absorption capacity of the alloy.

[0090] In some specific embodiments, the thickness of the isotope source 8 is 400 nm to 1000 nm. Specifically, the isotope source 8 is a tritium storage film. When the isotope source 8 decays, the β particles emitted from inside the isotope source 8 to the source surface are blocked and lost by atoms in the film. The emission power increases with the thickness and then tends to stabilize after reaching a certain amount. The maximum emission power can be obtained in the range of 400 nm to 1000 nm.

[0091] The specific preparation process is as follows:

[0092] 1. The substrate (sodium chloride) is polished and thinned. Using a 99.99% pure silicon target and a 99.99% pure lithium target, a silicon film with a thickness of 1-5 μm is deposited on the substrate surface using magnetron sputtering. A lithium metal film with a thickness of 1-2 μm is then prepared on the silicon film surface using magnetron sputtering. The deposition vacuum is 3.0 × 10⁻⁶. -4 The deposition process involves applying argon gas at a flow rate of 10-50 sccm, a deposition temperature of 25-100℃, a deposition bias voltage of 0-150V, a deposition pressure of 0.5-2Pa, a deposition time of 10-60 min, and a deposition power of 50-200W. After deposition, the silicon film is heated to 100-200℃ in a vacuum chamber and held for 10-30 min to allow the lithium film to fully diffuse into the silicon film, causing the silicon film to expand.

[0093] Generally, the substrate (sodium chloride) is polished and thinned. Alternatively, a 100-500 nm sodium iodide (NaI) thin film can be deposited on the surface of the glass slide using thermal evaporation technology.

[0094] 2. A lithium metal film with a thickness of 1-2 μm is then prepared on the surface of the expanded silicon film using magnetron sputtering technology, with a deposition vacuum of 3.0 × 10⁻⁶. -4 The deposition conditions are: Pa, argon flow rate 10-20 sccm, deposition temperature 25-30℃, deposition bias voltage 0-50V, deposition pressure 0.5-1 Pa, and deposition time 10-60 min.

[0095] 3. Take out the completed sample and place it in warm water at 25-90℃ for 1-2 hours to float. After the substrate (sodium chloride) has completely dissolved, put it in an oven to dry at 50℃ for 12 hours.

[0096] 4. The self-supporting lithium silicon film obtained from the dissolution is subjected to ion etching. After etching, a continuous wave structure with an outer convex diameter to an inner concave diameter ratio of (1-2):(0.5-1) is obtained. The etching process is as follows: In the passivation stage, the reaction gas is a mixture of 99.999% pure argon and 99.99% pure chlorine, with a mixing degree of (70-90) / (10-30). The working pressure is 10-20 Pa, the RF current frequency is 10-20 MHz, and the gas flow rate is 50-150 sccm. A bias voltage of 5-10 V is applied to the surface of the silicon film. In the etching stage, 99.999% pure argon is used, with a gas flow rate of 50-200 sccm, a working pressure of 10-20 Pa, and a bias voltage of 10-30 V with a frequency of 1-5 MHz applied to the surface of the silicon film.

[0097] 5. Using 3D printing or chemical vapor deposition, a silicon carbide layer with a thickness of 1-10 μm is grown on the surface of the etched silicon thin film. During the preparation of the silicon carbide substrate, the substrate temperature is 50-150℃, allowing the lithium layer to continue diffusing into the silicon thin film. After the silicon carbide layer is prepared, heating continues for 1-2 hours until the silicon thin film is completely crushed and detached, resulting in a structure with an outer convex diameter to an inner concave diameter ratio of (0.5-1):(1-2).

[0098] 6. P-type and N-type semiconductors are epitaxially grown on silicon carbide with a wavy structure surface, with a growth thickness of 1-5 μm.

[0099] Generally, when fabricating silicon carbide transducers, 3D printing or chemical vapor deposition is used to prepare the silicon carbide layer. In addition, when fabricating silicon or gallium nitride transducers, they are fabricated directly on the surface of the etched silicon substrate without the need for a silicon carbide layer.

[0100] 7. A tritium storage film with a thickness of 400-1000 nm was prepared on the surface of the fabricated P-type semiconductor using multi-target co-sputtering magnetron sputtering. Targets with a purity of 99.99% were selected, including Ti, Zr, V, Fe, Nb, Pd, Hf, Ni, Co, and Sc. Five of these targets were combined with a 99.999% pure Y target. The deposition vacuum was 3.0 × 10⁻⁶. -4 The deposition parameters are: Pa, argon flow rate 10-50 sccm, deposition temperature 300-600℃, deposition bias voltage 0-150V, deposition pressure 0.5-1Pa, deposition time 60-120min, and deposition power 5-100W.

[0101] 8. Place the coated sample into the hydrogen absorption device and evacuate the chamber to a vacuum of 5 × 10⁻⁶. -4 The solution is activated at 400-800℃ for 30-180 min, then cooled to 300-500℃, charged with 100-10000 Pa of tritium gas, and reacted for 1-12 h. This yields an isotope cell with power output characteristics.

[0102] The main advantages of this application are:

[0103] 1. Increasing the number of power generation modules improves the volumetric output power of isotope batteries. By fabricating a fragile layer 4 as a mold layer, transducer devices 6 with thicknesses ranging from 1 micrometer to 10 micrometers were fabricated. In existing technologies, the thickness of transducer devices 6 fabricated using conventional processes reaches over 400 micrometers, significantly hindering the miniaturization of isotope batteries. Under the same volume, the fabrication method in this application can increase space utilization, i.e., more transducer devices 5 can be placed in a limited space, achieving higher output power within the same volume; furthermore, the fabricated transducer device 6 with a three-dimensional structure can increase the contact area between the isotope source 8 and the transducer device 6, allowing the transducer device 6 to receive more β particles generated from the decay of the radioactive source, thereby increasing the output power of the power generation unit.

[0104] 2. Reduced fabrication costs and increased success rate. This application differs from methods that directly etch three-dimensional structures onto the surface of the transducer 6. By utilizing the structure of the mold layer to fabricate a special three-dimensional structure on the surface of the transducer 6, the deposition stress of the isotope source 8 film and the internal stress generated by the tritium absorption phase transition during the deposition of the isotope source 8 on the surface of the transducer 6 can be dispersed, reducing the force exerted by the isotope source 8 film on the transducer 6 and avoiding damage to the structure of the transducer 6. The method used in this application has a simple fabrication process, a high success rate, and can be commercially mass-produced.

[0105] In existing isotope batteries, the thickness of the semiconductor substrate for a single power generation unit is 170 μm, and the volume of a single power generation unit is 0.757 cm³.3 Compared to existing isotope batteries, the isotope battery in this application has a semiconductor substrate thickness of 1μm-10μm for each power generation unit and a volume of 0.0445cm³ for each power generation unit. 3 .

[0106] The volumetric power output of existing isotope solar cells is 2.805 μW / cm². 3 Compared to existing isotope batteries, the volumetric output power of the isotope battery in this application is 48.48 μW / cm². 3 .

[0107] The manufacturing cost of a single power generation unit in an existing isotope battery is approximately 20,000 yuan. Compared to existing isotope batteries, the manufacturing cost of a single power generation unit in the isotope battery of this application is approximately 8,000 yuan.

[0108] The yield rate of existing isotope batteries is 60%. Compared to existing isotope batteries, the success rate of the isotope batteries in this application is 80%.

[0109] In summary, the volume of the isotope battery obtained in this application is reduced by 17 times compared to existing isotope batteries, and the volumetric output power of the isotope battery is increased by 17 times compared to existing isotope batteries, reaching milliwatt-level power output. Furthermore, the manufacturing cost of a single power generation unit is reduced by 60%, and the success rate of isotope battery fabrication is increased from 60% to 80% compared to existing isotope battery fabrication success rates.

[0110] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0112] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0113] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0114] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0115] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A method for fabricating a transducer, characterized in that, include: S1: Prepare a fragile layer on the surface of a soluble substrate, the fragile layer comprising solvent atoms; S2: Prepare a first solute layer on the surface of the layer to be fragile, the first solute layer comprising solute atoms soluble in the layer to be fragile; S3: Heating at least one of the soluble substrate, the fragile layer to be broken, and the first solute layer, causing the solute atoms in the first solute layer to migrate to the fragile layer to be broken, thereby generating a fragile layer in the fragile layer; S4: a. Etch the surface of the fragile layer to generate a preset shape; b. Prepare a second solute layer on the surface of the fragile layer, the second solute layer comprising solute atoms soluble in the fragile layer; c. Dissolve the soluble substrate using a substrate solvent; In this case, at least one of a and b is located after c in chronological order, and the position of the second solute layer is opposite to the position of the preset shape on both sides of the fragile layer; S5: Prepare a transducer on the surface of the fragile layer having the preset shape; S6: Heat at least one of the transducer, the fragile layer, and the second solute layer, and the solute atoms in the second solute layer migrate to the fragile layer, causing the fragile layer to pulverize, thereby obtaining the transducer.

2. The method for fabricating the transducer according to claim 1, characterized in that, After S4 and before S5, the method for fabricating the transducer further includes: fabricating a transducer substrate on the surface of the fragile layer having the preset shape, and then fabricating the transducer device on the transducer substrate; The transducer substrate is made of the same material as the transducer device.

3. The method for fabricating the transducer according to claim 2, characterized in that, The transducer substrate is made of silicon carbide; and / or The thickness of the transducer substrate is 1 μm to 10 μm.

4. The method for fabricating the transducer according to claim 1 or 2, characterized in that, The transducer is made of silicon carbide.

5. The method for fabricating the transducer according to claim 1 or 2, characterized in that, The preset shape is wavy.

6. The method for fabricating the transducer according to claim 5, characterized in that, The ratio of the outer convex diameter of the wave-shaped section to the inner concave diameter of the wave-shaped section is (0.5-1):(1-2).

7. The method for fabricating the transducer according to claim 1 or 2, characterized in that, The soluble substrate is made of at least one of sodium chloride, potassium iodide, and sodium iodide; and / or The surface finish of the soluble substrate is greater than 0.

6.

8. The method for fabricating the transducer according to claim 7, characterized in that, The substrate solvent is water.

9. The method for fabricating the transducer according to claim 1 or 2, characterized in that, The material of the fragile layer is silicon; and / or The thickness of the fragile layer is 1 μm to 5 μm; and / or The material of the first solute layer is lithium; and / or The thickness of the first solute layer is 1 μm to 2 μm; and / or The material of the second solute layer is lithium; and / or The thickness of the second solute layer is 1 μm to 2 μm.

10. A method for preparing an isotope battery, characterized in that, The method for preparing the isotope battery includes the method for preparing the transducer according to any one of claims 1-9.

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