Preparation method of nanosphere silicon with silicon-hydrogen shell

Abstract

The invention discloses a preparation method of nanosphere silicon with a silicon-hydrogen protection shell. The nanosphere silicon which is high in purity and uniform in particle size distribution is prepared by adopting a two-step method, wherein in the first preparation method, the micron-scale silicon granules which are regular in size and uniform to distribute are prepared without introducing impurities by using an electric arc plasma method; and in the second step, the nano silicon surface oxide is further removed by using an acidic organic compound to obtain nanosphere silicon through grinding and eroding actions, and simultaneously a grafting reaction is carried out to form the silicon-hydrogen protecting shell. According to the nanosphere silicon prepared by using the preparation method disclosed by the invention, the uniformity of the initial size and the size distribution is ensured, and in addition, the oxidation resistance of the nano silicon can be enhanced by virtue of the silicon-hydrogen protection shell on the surface of the nanosphere silicon, therefore the agglomeration problem is effectively solved.

Description

technical field [0001] The invention relates to a method for preparing nano-spherical silicon with a silicon-hydrogen shell, and belongs to the field of new energy and nanotechnology new material manufacturing. Background technique [0002] As a non-metallic semiconductor material, silicon has a wide band gap. It is currently the main raw material for solar cells and can also be used to make semiconductor devices and integrated circuits. Due to its nanostructure, high-purity nano-silicon also has excellent physical and chemical properties, such as quantum size effect, quantum tunneling effect and special photoelectric properties, so it is widely used in optoelectronic devices, optical communications, solar cells and silicon-based optical integration. It has great application potential. [0003] The existing nano-preparation technology can be simply summarized into two types of methods: one is to split the bulk solid into nanoparticles (from large to small); the other is to ...

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Problems solved by technology

[0005] Question 1. Method 1 (from large to small) mainly uses mechanical and physical methods to crush, and friction makes the particle size of the material continuously smaller. Although the process is simple, it is easy to introduce foreign impurities and cause low product purity, which greatly affects its functional properties. ; And through the second method (from small to large), then separation, collection difficulties, low yield, high energy consumption, high cost, not suitable for large-scale production

[0006] Question 2, the products made by the above two methods, because the surface atoms of the nanomaterials are in a highly activated state, the surface energy of the nanoparticles is high and easy to agglomerate into large particles, and it is very easy to oxidize with oxygen in the air to form silicon oxide

[0007] Question 3 The products made by the above two methods are all directly formed nanoparticles in one step, and the nanoparticles are irregular in shape and extremely wide in particle size distribution.

[0009] 1. Because the surface atoms of nanomaterials are in a highly activated state, the surface energy of nanoparticles is high and easy to agglomerate, and it is very easy to oxidize with oxygen in the air, so it is not easy to store for a long time;

[0010] 2. The nanomaterials prepared by vacuum condensation method, vapor deposition method, laser dehydrogenation method and other technologies are small in size, but they have high requirements for equipment and process, and consume a lot of energy, so they cannot be produced on an industrial scale;

[0011] 3. Although the physical method such as mechanical ball milling method is simple in process, it is easy to introduce foreign impurities, resulting in low product purity, which greatly affects its functional characteristics, and random mechanical crushing makes the particle shapes different and the particle size distribution is extremely wide;

[0012] 4. Using chemically synthesized nanomaterials such as microemulsion method and sol-gel method, the separation and drying process is complicated and will pollute the environment

[0013] The above nanotechnology is often used in the research and development and preparation of nanomaterials such as metal materials, oxides, carbides, nitrides, etc., and the research and development and reports of semiconductor high-purity nano-silicon materials (above 6N level) are rarely seen.

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