A modular micro nuclear power source and a micro nuclear power source device

Abstract

The present invention relates to a modular micro nuclear power source and a micro nuclear power source device. The micro nuclear power source is composed of a radioactive isotope layer, a nuclear power conversion module, a thermoelectric conversion module, and a power management device. In the present invention, the nuclear power conversion module can convert the decay energy of radioactive isotopes into electrical energy, and the thermoelectric conversion module can convert the low-grade waste heat released by the radioactive isotope layer and the nuclear power conversion module into electrical energy. This sandwich-type structure realizes the multi-stage efficient utilization of nuclear energy and is also conducive to large-scale production and assembly on demand, etc.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear energy and thermal energy utilization, and relates to a modular micro nuclear power source and its application. Background Technique

[0002] A nuclear battery is a device that can convert the energy stored in radioactive isotopes into electrical energy. Nuclear batteries have the advantages of high energy density, long service life, strong anti-interference ability, small volume, light weight, easy miniaturization and integration, etc., and have great application prospects in polar regions, deep seas, deserts, deep space and other fields.

[0003] According to the utilization mode of nuclear energy, nuclear batteries can be divided into the following two categories: the first category is the thermoelectric conversion mechanism, that is, converting the heat released during the decay of radioactive isotopes into electrical energy; the second category is the radiation particle conversion mechanism, that is, directly or indirectly converting the radiation particles of radioactive isotopes into electrical energy. The nuclear battery based on the radiovoltaic effect uses the particles emitted during the decay of radioactive isotopes to bombard the semiconductor material, generating a large number of electron-hole pairs inside the material. These electron-hole pairs move directionally under the action of the built-in electric field of the semiconductor device to form an electric current.

[0004] At present, there have been a large number of studies on nuclear batteries based on the radiovoltaic effect, mainly focusing on the improvement of the energy conversion unit, exploring the influence of new structures and new materials on the output performance of nuclear batteries. However, there are still huge challenges in the modular design of nuclear battery devices and the multi-stage utilization of nuclear energy. Summary of the Invention

[0005] The purpose of the present invention is to provide a modular micro nuclear power source and a micro nuclear power source device.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] One of the technical solutions of the present invention provides a modular micro nuclear power source, including a radioactive isotope layer, two nuclear power conversion modules symmetrically arranged on both sides of the radioactive isotope layer, and two thermoelectric conversion modules symmetrically arranged outside the two nuclear power conversion modules.

[0008] Furthermore, the radioactive source of the radioactive isotope layer can be nickel-63, krypton-85, strontium-90 or promethium-147. In addition, its thickness is 2-50 μm.

[0009] Furthermore, the nuclear power conversion module is composed of a high-resistance substrate, a lower electrode, a nuclear power conversion unit and an upper electrode arranged in sequence, and the upper electrode is attached to the radioactive isotope layer.

[0010] Furthermore, the nuclear power conversion unit is a PN junction, a PIN junction or a Schottky diode. Its material can be silicon, gallium arsenide, silicon carbide, gallium nitride or diamond, and the thickness is 1-20 μm. The nuclear power conversion unit itself does not involve the innovative improvement points of the present invention. The materials of the upper electrode and the lower electrode can be gold, silver, copper or platinum, and the thickness is 50-500 nm.

[0011] Furthermore, the number of the nuclear power conversion units is n, where n≥1.

[0012] Furthermore, the material of the high-resistance substrate can be silicon, germanium, silicon carbide, gallium nitride or gallium arsenide, and the thickness is 100-10000 μm.

[0013] Further, the thermoelectric power conversion module is composed of a substrate, a bottom electrode, a thermopile and a top electrode. The thermopile is composed of P-type thermoelectric columns and N-type thermoelectric columns. Both ends of the P-type thermoelectric columns and the N-type thermoelectric columns are respectively connected to the bottom electrode and the top electrode. The bottom electrode and the top electrode are also arranged in sections, and all the thermopiles are connected to form a series structure.

[0014] Furthermore, the number of pairs of the thermopile is m, where m≥1, and specifically can be 1-100000 pairs.

[0015] Furthermore, a heat sink is provided on the outer side of the substrate.

[0016] Furthermore, the substrate is a silicon wafer, a glass sheet, a ceramic sheet or a flexible polymer film, and the thickness is 100-10000 μm.

[0017] Furthermore, the height of the thermopile is 1-20 μm.

[0018] Further, the radioactive isotope layer, the nuclear power conversion module and the thermoelectric power conversion module are connected together by adsorption, bonding or keying.

[0019] Further, the modular micro nuclear power source further includes an isolation and protection layer for encapsulating it. Specifically, the isolation and protection layer is prepared by combining one or more of metals that can shield β-particle radiation.

[0020] The second technical solution of the present invention provides a micro nuclear power source device, which includes the modular micro nuclear power source as described above, and a power management module. An internal circuit is also provided in the modular micro nuclear power source to conduct the electric energy generated by the nuclear power conversion module and the thermoelectric power conversion module to the power management module for storage and release as needed. The power management module is a conventional control module in the art with the functions of electric energy storage and release, and it can provide reliable and stable electric energy supply for integrated circuits.

[0021] Further, one or several modular micro nuclear power sources are provided. When several modular micro nuclear power sources are provided, all modular micro nuclear power sources are connected in series to form a nuclear power source group.

[0022] When one modular micro nuclear power source is provided, the bottom electrodes of the two thermoelectric conversion modules are respectively connected to the lower electrode and the upper electrode in the nuclear power conversion module on the same side through internal circuits, and the other upper electrode and lower electrode in the two nuclear power conversion modules are also connected and communicated through internal circuits. At the same time, the bottom electrodes of the two thermoelectric conversion modules are also respectively connected to the power management module.

[0023] In the present invention, multiple nuclear power conversion modules 2 and thermoelectric conversion modules 1 are assembled on both sides of the radioactive isotope layer, and the utilization efficiency of the decay energy of the radioactive isotope is improved through multi-stage utilization. For the nuclear power conversion module, due to being bombarded by β particles of the radioactive isotope layer 7, electron-hole pairs are formed inside it, and under the action of the built-in electric field, they move directionally to form a current. The internal current direction of the nuclear power conversion module is from the direction far away from the radioactive isotope layer to the direction close to the radioactive isotope layer, that is, from the lower electrode 4 to the upper electrode 6. For the thermoelectric conversion module, the longitudinal heat flow direction is always from the direction close to the radioactive isotope layer to the side of the substrate 12, that is, from the top electrode 11 to the bottom electrode 8. In the P-type thermoelectric column (9) with holes as carriers, its current is in the same direction as the heat flow, and in the N-type thermoelectric column 10 with electrons as carriers, its current is in the opposite direction to the heat flow. The above currents are connected in series in the same direction through internal circuits and stored and released as needed through the power management module 13 to realize power supply for the integrated circuit 17.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] ① The nuclear power source device of the present invention is composed of a radioactive isotope layer, a nuclear power conversion module, and a thermoelectric conversion module. The nuclear power conversion module can convert the decay energy of the radioactive isotope into electrical energy, and the thermoelectric conversion module can convert the low-grade waste heat released by the radioactive isotope layer and the nuclear power conversion module into electrical energy.

[0026] ② The sandwich-type structure of the present invention realizes multi-stage and efficient utilization of nuclear energy, reduces the impact of isotope radiation on the environment, and at the same time reduces the interference with the integrated circuit signal.

[0027] ③ The heat sink around the thermoelectric conversion module of the present invention not only helps to reduce the temperature of the integrated circuit, but also helps to increase the temperature difference at both ends of the thermoelectric conversion module, thereby increasing the output voltage.

[0028] ④ Based on the characteristics of modular assembly, it is convenient for large-scale production and on-demand assembly.

[0029] ⑤The present invention realizes the miniaturization of nuclear power sources and reduces the danger of reactor meltdowns. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the modular micro nuclear power source device provided by the present invention;

[0031] Figure 2 It is a schematic diagram of two sets of modular micro nuclear power source devices provided by the present invention connected in series;

[0032] Figure 3 It is an energy conversion diagram of the modular micro nuclear power source device provided by the present invention;

[0033] Description of the marks in the figure:

[0034] 1. Thermoelectric conversion module; 2. Nuclear power conversion module; 3. High-resistance substrate; 4. Lower electrode; 5. Nuclear power conversion unit; 6. Upper electrode; 7. Radioisotope layer; 8. Bottom electrode; 9. P-type thermoelectric column; 10. N-type thermoelectric column; 11. Top electrode; 12. Substrate; 13. Power management module; 14. Isolation and protection layer; 15. Heat sink; 16. Internal circuit; 17. Integrated circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives detailed implementation manners and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments. It should be noted that the present invention can be implemented in different forms and should be adjusted according to the actual situation. The proposed embodiments are intended to achieve a full and complete disclosure, enabling those skilled in the art of this technology to fully understand the scope of the present invention and should not be construed as being limited by the proposed embodiments.

[0036] In the following reference drawings, for convenience of description, the sizes of different layers and regions are enlarged or reduced, so the sizes shown do not necessarily represent the actual sizes and do not reflect the proportional relationship of the sizes. The reference drawings are schematic diagrams of idealized embodiments of the present invention, and the embodiments shown in the present invention should not be considered limited to the specific shapes of the regions shown in the drawings, but include the obtained shapes, such as deviations caused by manufacturing. In the embodiments of the present invention, each part is represented by a rectangle, and the representation in the drawings is schematic, but this should not be considered as limiting the scope of the present invention.

[0037] One of the technical solutions of the present invention provides a modular micro nuclear power source. Please refer to Figure 1 as shown, which includes a radioisotope layer 7, two nuclear power conversion modules 2 symmetrically arranged on both sides of the radioisotope layer 7, and two thermoelectric conversion modules 1 symmetrically arranged outside the two nuclear power conversion modules 2. The overall size of the micro nuclear power source is at the centimeter level or below.

[0038] In some specific embodiments, the radioactive source of the radioactive isotope layer 7 can be nickel-63, krypton-85, strontium-90 or promethium-147. Additionally, its thickness is 2 - 50 μm.

[0039] In some specific embodiments, the nuclear power conversion module 2 is composed of a high-resistance substrate 3, a lower electrode 4, a nuclear power conversion unit 5, and an upper electrode 6 arranged in sequence, and the upper electrode 6 adheres to the radioactive isotope layer 7.

[0040] In a more specific embodiment, the nuclear power conversion unit 5 is a PN junction, a PIN junction or a Schottky diode. Its material can be silicon, gallium arsenide, silicon carbide, gallium nitride or diamond, and its thickness is 1 - 20 μm. The nuclear power conversion unit 5 itself does not involve the innovative improvement points of the present invention. The materials of the upper electrode 6 and the lower electrode 4 can be gold, silver, copper or platinum, and their thicknesses are 50 - 500 nm.

[0041] In a more specific embodiment, the number of the nuclear power conversion units 5 is n, where n ≥ 1.

[0042] In a more specific embodiment, the material of the high-resistance substrate 3 can be silicon, germanium, silicon carbide, gallium nitride or gallium arsenide, and its thickness is 100 - 10000 μm.

[0043] In some specific embodiments, the thermoelectric conversion module 1 is composed of a substrate 12, a bottom electrode 8, a thermopile, and a top electrode 11. The thermopile is composed of P-type thermoelectric columns 9 and N-type thermoelectric columns 10. Both ends of the P-type thermoelectric columns 9 and N-type thermoelectric columns 10 are respectively connected to the bottom electrode 8 and the top electrode 11. The bottom electrode 8 and the top electrode 11 are also arranged in segments and all the thermopiles are connected to form a series structure.

[0044] In a more specific embodiment, the number of pairs of the thermopile is m, where m ≥ 1, and specifically can be 1 - 100000 pairs.

[0045] In a more specific embodiment, a heat sink 15 is further provided outside the substrate 12.

[0046] In a more specific embodiment, the substrate 12 is a silicon wafer, a glass sheet, a ceramic sheet or a flexible polymer film, and its thickness is 100 - 10000 μm.

[0047] In a more specific embodiment, the height of the thermopile is 1 - 20 μm.

[0048] In some specific embodiments, the radioactive isotope layer 7, the nuclear power conversion module 2, and the thermoelectric conversion module 1 are connected together by adsorption, bonding or keying.

[0049] In some specific embodiments, the modular micro nuclear power source further includes an isolation and protection layer 14 for encapsulating it. Specifically, the isolation and protection layer 14 is prepared by combining one or several metals that can shield β-particle radiation.

[0050] In addition, the present invention also provides a micro nuclear power source device. Please refer to Figures 1 to 3 As shown, it includes the modular micro nuclear power source as described above, and a power management module 13. An internal circuit 16 is also provided in the modular micro nuclear power source to conduct the electric energy generated by the nuclear power conversion module 2 and the thermoelectric conversion module 1 to the power management module 13 for storage and release as needed, so as to supply power to the integrated circuit 17. The power management module 13 is a conventional control module in the art with functions of electric energy storage and release.

[0051] In some specific embodiments, one or several modular micro nuclear power sources are provided. When several modular micro nuclear power sources are provided, all the modular micro nuclear power sources are connected in series to form a nuclear power source group.

[0052] When one modular micro nuclear power source is provided, the bottom electrodes 8 of the two thermoelectric conversion modules 1 are respectively connected to the lower electrode 4 and the upper electrode 6 in the nuclear power conversion module 2 on the same side through the internal circuit 16, and the other upper electrode 6 and lower electrode 4 in the two nuclear power conversion modules are also connected and communicated through the internal circuit 16. At the same time, the bottom electrodes 8 of the two thermoelectric conversion modules 1 are also respectively connected to the power management module 13.

[0053] The above embodiments can be implemented separately, or any two or more of them can be combined and implemented.

[0054] The above embodiments will be described in more detail below in conjunction with specific examples.

[0055] Example 1:

[0056] Based on the standard MEMS processing technology, the embodiments of the present invention utilize exposure, development, thin film deposition and stripping processes to provide a technical solution and preparation method for preparing a modular micro nuclear power source.

[0057] The preparation method of the nuclear power conversion module 2 is specifically as follows:

[0058] (1) Adopt a mechanical polishing and thinning process to make the thickness of a 2*2 cm single-sided polished silicon carbide substrate 300 μm; clean the impurities on the surface of the silicon carbide substrate with acetone, methanol, isopropyl alcohol and deionized water, and then dry the substrate on a hot plate to obtain a high-resistance substrate 3.

[0059] (2) Use magnetron sputtering technology to deposit 100 nm of gold on the silicon carbide substrate as the lower electrode 4.

[0060] (3) Prepare an N-type highly doped silicon carbide layer and a P-type lowly doped silicon carbide layer on a silicon carbide substrate by using microwave plasma chemical vapor deposition and ion implantation techniques to form a silicon carbide PN junction. The thickness of the silicon carbide PN junction is 2 μm, thus obtaining the nuclear power conversion unit 5.

[0061] (4) Deposit 100 nm of gold on the passivation layer by using magnetron sputtering technology as the upper electrode 6.

[0062] (5) Anneal the nuclear power conversion device under the protection of normal-temperature nitrogen.

[0063] The preparation method of the thermoelectric conversion module 1 in this micro nuclear power source is specifically as follows:

[0064] (1) Clean the impurities on the surface of a 500-μm-thick silicon oxide substrate with a size of 2 * 2 cm by using acetone, methanol, isopropyl alcohol, and deionized water, and dry the substrate with a hot plate to obtain the substrate 12.

[0065] (2) Spin-coat photoresist and perform mask exposure and development.

[0066] (3) Deposit 200 nm of gold by using magnetron sputtering technology and place it in acetone for stripping, leaving part of the bottom electrode 8.

[0067] (4) Deposit Bi2Te3 on the bottom electrode 8 as the N-type thermoelectric column 10 and Sb2Te3 as the P-type thermoelectric column 9. The height of the thermoelectric column is 3 μm, and the number of pairs of thermoelectric columns is 512 pairs, that is, there are 512 N-type thermoelectric columns 10 and 512 P-type thermoelectric columns 9 each.

[0068] (5) Fill the support glue and deposit 200 nm of gold as the top electrode 11.

[0069] (6) Use oxygen plasma treatment to remove the support glue.

[0070] (7) Perform annealing treatment under the protection of nitrogen at 100 °C to obtain the thermoelectric conversion module 1.

[0071] The assembly method of this micro nuclear power source is specifically as follows:

[0072] (1) Clamp a nickel-63 radioactive isotope layer 7 with a size of 2 * 2 cm and a thickness of 2 μm with two nuclear power conversion modules 2, and the substrate of the nuclear power conversion module 2 faces outward.

[0073] (2) Clamp the above two nuclear power conversion modules 2 with two thermoelectric conversion modules 1, and connect the top electrode 11 of the thermoelectric conversion module 1 to the substrate of the nuclear power conversion module 2.

[0074] (3) Clamp the above two thermoelectric conversion modules 1 with two heat sinks 15 and connect them to the bottom electrode 8 of the thermoelectric conversion module 1.

[0075] (4) Connect the electrodes of the two thermoelectric conversion modules 1 and the two nuclear power conversion modules 2 with the internal circuit 16, and connect them to the power management module 13.

[0076] (5) Package the part between the two heat sinks 15 with the isolation and protection layer 14.

[0077] Specifically, the radioactive isotope layer 7 generates particle bombardment on the nuclear power conversion units 5 on both sides. Inside the nuclear power conversion unit 5, the current direction is always from the side far from the radioactive isotope layer 7 to the side close to the radioactive isotope layer 7. Therefore, the lower electrode of the upper nuclear power conversion device needs to be connected to the upper electrode of the lower nuclear power conversion unit to form a series structure. In the thermoelectric conversion device, the side close to the radioactive isotope layer 7 is the high-temperature end. For the P-type thermoelectric column 9, the current direction is always from the high-temperature end to the low-temperature end, and the N-type thermoelectric column 10 is opposite. Therefore, connecting these local currents in the same direction can supply power to the external circuit.

[0078] Embodiment 2:

[0079] Compared with Embodiment 1, most of them are the same, except that in this embodiment, the number of pairs of thermoelectric columns is 46000.

[0080] Embodiment 3:

[0081] Compared with Embodiment 1, most of them are the same, except that in this embodiment, the number of silicon carbide PN junctions is 4.

[0082] Embodiment 4:

[0083] Compared with Embodiment 1, most of them are the same, except that in this embodiment, the energy supply device is composed of two micro nuclear power sources connected in series, see Figure 2 .

[0084] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Those skilled in the art can obviously make various modifications to these embodiments easily and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A modular micro nuclear power source, characterized in that, It includes a radioactive isotope layer, two nuclear power conversion modules symmetrically arranged on both sides of the radioactive isotope layer, and two thermoelectric power conversion modules symmetrically arranged outside the two nuclear power conversion modules; The nuclear power conversion module is composed of a high-resistance substrate, a lower electrode, a nuclear power conversion unit, and an upper electrode arranged in sequence, and the upper electrode adheres to the radioactive isotope layer; The nuclear power conversion unit is a PN junction, a PIN junction, or a Schottky diode; The thermoelectric power conversion module is composed of a substrate, a bottom electrode, a thermopile, and a top electrode. The thermopile is composed of P-type thermoelectric columns and N-type thermoelectric columns. Both ends of the P-type thermoelectric columns and N-type thermoelectric columns are respectively connected to the bottom electrode and the top electrode. The bottom electrode and the top electrode are also arranged in segments, and all the thermopiles are connected to form a series structure; A heat sink is further arranged outside the substrate; the radioactive isotope layer, the nuclear power conversion module, and the thermoelectric power conversion module are connected together by adsorption, bonding, or keying.

2. The modular micro nuclear power source according to claim 1, characterized in that The number of the nuclear power conversion units is n, and n≥1.

3. A modular micro nuclear power source according to claim 1, characterized in that, The number of pairs of the thermopile is m, and m≥1.

4. A micro nuclear power device, which includes the modular micro nuclear power as described in any one of claims 1-3, and a power management module. An internal circuit is further provided in the modular micro nuclear power to conduct the electric energy generated by the nuclear power conversion module and the thermoelectric power conversion module to the power management module for storage and release as needed.

5. A micro nuclear power supply device according to claim 4, characterized in that, One or several modular micro nuclear powers are provided. When several modular micro nuclear powers are provided, all the modular micro nuclear powers are connected in series to form a nuclear power group.

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