CN111968772A - Heterojunction isotope battery based on graphene - Google Patents

Abstract

The invention provides a graphene-based heterojunction isotope battery, comprising a graphene heterojunction energy conversion structure and a radiation source matched with the graphene heterojunction energy conversion structure, the graphene heterojunction energy conversion structure The energy conversion structure includes a substrate material layer, a back electrode arranged on the back side of the substrate material layer, a graphene layer arranged on the front side of the substrate material layer, the graphene layer and the substrate material layer A heterojunction is formed between them. The invention adopts graphene and semiconductor materials to form a heterojunction, the thickness of the graphene of the heterojunction metal layer is only a few nanometers, the absorption and blocking effect of the metal layer on the source layer is reduced, and the work function of the graphene is relatively high, It can form a large built-in electric field with semiconductor materials, which is conducive to the improvement of open circuit voltage. At the same time, graphene can also be used as an electrode material, which further reduces the energy loss of decay particles of radioactive sources and improves the overall energy conversion efficiency of isotope batteries.

Description

A graphene-based heterojunction isotope battery

technical field

The invention belongs to the field of isotope batteries, relates to a radiation volt-type isotope battery, in particular to a graphene-based heterojunction isotope battery.

Background technique

An isotope battery is an energy supply device that converts the decay energy of a radioisotope source into electrical energy through a certain energy conversion method. Radiation Voltaic Isotope Battery (RVIB) is a device that converts charged particle energy released by isotope decay into electrical energy through semiconductors. It has the natural advantages of easy miniaturization and long working life, and its environmental adaptability is strong. With good stability and no maintenance, it is expected to be the best power supply for micro-electromechanical systems (MEMS).

In the published isotope battery patents, most of the radiation volt-type isotope batteries use PN junction, that is, under the action of the built-in electric field formed by the PN junction, the separation of electron-hole pairs is realized, so as to realize the output of current, but, The traditional radiovoltaic PN junction isotope battery requires an additional metal thin-layer composite electrode as the electrode to lead out, which further enhances the attenuation of the radiation source rays, resulting in low energy conversion efficiency of the traditional radiovoltaic isotope battery. The current existing isotope batteries generally have low energy conversion efficiency, high production costs, and some design processes are difficult to process. There is an urgent need to design a simple and easy-to-process isotope battery with high energy conversion efficiency.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a kind of graphene-based battery that can increase the built-in electric field strength formed between graphene and semiconductor with energy efficiency, improve the effective separation and transmission of carriers, and then improve the energy conversion efficiency of isotope batteries. Heterojunction isotope cells.

In order to achieve the above purpose, the technical scheme of the present invention is achieved in this way: a graphene-based heterojunction isotope battery, comprising a graphene heterojunction energy conversion structure and matching with the graphene heterojunction energy conversion structure The radiation source, the graphene heterojunction energy conversion structure comprises a substrate material layer, a back electrode arranged on the back side of the substrate material layer, a graphene layer arranged on the front side of the substrate material layer, so A heterojunction is formed between the graphene layer and the substrate material layer.

Further, one side of the substrate material layer connected to the graphene layer is formed with an insulating passivation layer to saturate the dangling bonds on the surface of the substrate material, thereby reducing the interface state density and making the interface current-carrying. The sub-concentration is reduced, ultimately improving the electrical properties of the heterojunction.

Further, the material of the insulating passivation layer is any one of silicon dioxide, aluminum oxide, sulfur, hydrogen, and silicon nitride.

Further, the graphene layer is directly drawn out as the upper electrode, which further reduces the energy loss of the decaying particles of the radioactive source, and the graphene layer is provided with at least one layer.

Further, the substrate material layer is a semiconductor material, and the semiconductor material is an elemental element semiconductor or a compound semiconductor or a third-generation semiconductor.

Preferably, the elemental element semiconductor is any one of silicon, germanium, selenium, or other types of elemental element semiconductors; the compound semiconductor is any one of gallium arsenide, indium telluride, or other types of semiconductors Compound semiconductor; the third-generation semiconductor is any one of silicon carbide, gallium nitride, zinc oxide, diamond, or other types of third-generation semiconductor materials.

Further, the back electrode is any one of a platinum electrode, a gold electrode, an indium gallium electrode, and a copper electrode.

Further, the radioactive source includes a radioactive source substrate material layer and a radioisotope source capable of emitting decay particles, the radioisotope source is arranged on a side of the radioactive source close to the graphene layer, and the radioactive isotope source is The source substrate material layer is disposed on the side of the radiation source away from the graphene layer.

Further, the material layer of the radioactive source substrate material is selected from a material capable of coupling or adsorbing the radioisotope source.

Further, the radioisotope source is a beta radioisotope source or an alpha radioisotope source.

Preferably, the β radioisotope source is any one of ³ H, ⁶³ Ni, ⁹⁰ Sr, ¹³⁷ Cs, ¹⁴⁴ Ce, ¹⁴⁷ Pm, or other types of β radioisotope sources, and the α radioisotope source is ²¹⁰ Po Any one of , ²²⁶ Ra, ²³⁸ Pu, ²⁴¹ Am, ²⁴⁴ Cm, or other alpha radioisotope sources.

Further, the graphene heterojunction energy conversion structure and the radiation source form a battery unit, and a plurality of the battery units are butt-packed in series or in parallel or in a multi-layered battlement.

The beneficial effects of the present invention are embodied in:

1. The present invention adopts graphene and semiconductor materials to form a heterojunction, and the thickness of the graphene of the heterojunction metal layer is only a few nanometers, which reduces the absorption and blocking effect of the metal layer on the source layer as much as possible; The function is higher, and it can form a larger built-in electric field with the semiconductor material, which is beneficial to the improvement of the open circuit voltage; at the same time, graphene can also be used as an electrode material, which further reduces the energy loss of the decaying particles of the radioactive source. The design of the present invention maximizes the overall energy conversion efficiency of the isotope battery.

2. The graphene material of the present invention has an ultra-thin thickness, which can effectively reduce the volume size of the isotope battery, and can achieve flexible output of different powers by stacking battlements and combining in series and parallel mode. The invention has simple structure, small volume, easy production and processing, and can be combined flexibly according to different working environments, thereby expanding the application range of the device.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Figure 1 is a schematic structural diagram of a graphene-based heterojunction isotope cell.

Description of reference numbers:

1. Energy conversion structure; 11. Substrate material layer; 12. Back electrode; 13. Insulation passivation layer; 14. Graphene layer; 2. Radioactive source; 21. Radioactive source substrate material layer; 22. Radioisotope source .

Detailed ways

The technical solutions in the embodiments of the invention will be clearly and completely described below with reference to the drawings in the embodiments of the invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. The embodiments in this application and the features in the embodiments may be combined with each other without conflict. Based on the embodiments in the invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the invention.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the invention, the directional indications are only used to explain a certain posture (as shown in the accompanying drawings). ), the relative positional relationship, movement situation, etc. between the components under ), if the specific posture changes, the directional indication also changes accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the invention, the descriptions of "first", "second", etc. are only used for description purposes, and should not be construed as indicating or implying that Relative importance or implicit indication of the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the meaning of "and/or" in the whole text includes three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, scheme B, or scheme satisfying both of A and B. In addition, "a plurality" means two or more. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the protection scope of the invention.

See Figure 1.

The graphene-based heterojunction isotope battery provided by the present invention includes a graphene heterojunction energy conversion structure 1 and a radiation source 2 matched with the graphene heterojunction energy conversion structure 1, and the graphene heterojunction energy conversion structure 1 is matched. The junction energy conversion structure 1 includes a substrate material layer 11, a back electrode 12 arranged on the back side of the substrate material layer 11, a graphene layer 14 arranged on the front side of the substrate material layer 11, the graphene layer A heterojunction is formed between 14 and the substrate material layer 11 .

Specifically, a side surface of the substrate material layer 11 connected to the graphene layer 14 is formed with a passivation insulating layer 13 for saturating the dangling bonds on the surface of the substrate material layer 11 .

The radioactive source 2 includes a radioactive source substrate material layer 21 and a radioisotope source 22 capable of emitting decay particles, the radioisotope source 22 is arranged on a side of the radioactive source 2 close to the graphene layer 14, The radiation source substrate material layer 21 is disposed on the side of the radiation source 2 away from the graphene layer 14 .

In one embodiment, the specific design is as follows:

In the design of a graphene-based heterojunction isotope battery provided in this embodiment, the substrate material layer 11 is monocrystalline silicon, which is purchased from Hefei Kejing Co., Ltd., the specification is: 1cm×1cm; the back electrode 12 is made of Au material , formed by magnetron sputtering, with a thickness of 40 nm; the insulating passivation layer 13 is made of SiO ₂ material, formed by natural oxidation, and has a thickness of 2 nm; the graphene layer 14 is set to 3-5 layers, and the substrate etching method is transferred, and the thickness is 1 nm; The radioactive isotope source 22 is a radioactive ⁶³ Ni source with a thickness of 200 nm; the radioactive source substrate material layer 21 is a Ni film supporting the radioactive isotope source 22 with a thickness of 200 μm.

The experimental results show that the open-circuit voltage of the battery is 0.2V, the short-circuit current is 365nA, and the conversion efficiency of the device reaches 0.9%, which is 0.67% higher than the conversion efficiency reported by Andrey in "A nuclear battery based on silicon pin structures with electroplating ⁶³ Ni layer" in 2019, an increase of 34%. %. It shows that the use of graphene heterojunction as the energy conversion material can effectively improve the comprehensive performance of the radiation volt effect battery.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A heterojunction isotope battery based on graphite alkene which characterized in that: including graphite alkene heterojunction energy conversion structure (1) and with graphite alkene heterojunction energy conversion structure (1) matched with radiation source (2), graphite alkene heterojunction energy conversion structure (1) includes substrate material layer (11), sets up back electrode (12) at the back of substrate material layer (11), sets up positive graphite alkene layer (14) of substrate material layer (11), graphite alkene layer (14) with form the heterojunction between substrate material layer (11).

2. The graphene-based heterojunction isotope battery of claim 1, wherein: and a passivation insulating layer (13) used for saturating dangling bonds on the surface of the substrate material layer (11) is formed on one side surface, connected with the graphene layer (14), of the substrate material layer (11).

3. The graphene-based heterojunction isotope battery of claim 2, wherein: the insulating passivation layer (13) is made of any one of silicon dioxide, aluminum oxide, sulfur, hydrogen and silicon nitride.

4. A graphene-based heterojunction isotope battery according to claim 1, 2 or 3, wherein: the graphene layer (14) is directly led out as an upper electrode, and at least one layer is arranged on the graphene layer (14).

5. A graphene-based heterojunction isotope battery according to claim 1, 2 or 3, wherein: the substrate material layer (11) is a semiconductor material, and the semiconductor material is a simple substance element semiconductor, a compound semiconductor or a third generation semiconductor.

6. A graphene-based heterojunction isotope battery according to claim 1, 2 or 3, wherein: the back electrode (12) is made of any one of a platinum electrode, a gold electrode, an indium-gallium electrode and a copper electrode.

7. A graphene-based heterojunction isotope battery according to claim 1, 2 or 3, wherein: the radioactive source (2) comprises a radioactive source substrate material layer (21) and a radioactive isotope source (22) capable of emitting decay particles, the radioactive isotope source (22) is arranged on one side, close to the graphene layer (14), of the radioactive source (2), and the radioactive source substrate material layer (21) is arranged on one side, away from the graphene layer (14), of the radioactive source (2).

8. The graphene-based heterojunction isotope battery of claim 7, wherein: the radioactive source substrate material layer (21) is made of a material capable of coupling or adsorbing the radioactive isotope source (22).

9. The graphene-based heterojunction isotope battery of claim 7, wherein: the radioisotope source (22) is a beta radioisotope source or an alpha radioisotope source.

10. A graphene-based heterojunction isotope battery according to claim 1, 2 or 3, wherein: the graphene heterojunction energy conversion structure (1) and the radioactive source (2) form a battery unit, and a plurality of battery units are in butt joint packaging in a series connection or parallel connection or multi-layer crenellation mode.

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