Method for preparing doping porous silicon ball

Abstract

The invention discloses a method for preparing a doping porous silicon ball. The method includes the steps that a silicon ball with certain doping content is selected, after being washed by hydrofluoric acid, the silicon ball is immersed in solutions formed by nitrate and hydrofluoric acid, after ultrasonic processing is carried out, the silicon ball is immersed in solutions prepared by the hydrofluoric acid and oxidizing agents and reacts at a certain temperature for a certain time period, then the silicon ball is washed in a centrifugal mode, and ultimately the nano porous silicon ball is prepared after nitric acid washing and other post-processing procedures. The best variety and the best concentration of reaction solutions, the optimum proportion of components, the best reaction temperature, the best reaction time, best ultrasonic frequency and best ultrasonic processing time are screened out through a large quantity of experiments. According to the whole preparation method, process design is reasonable, operability is high, production cost is low, production efficiency is high, and large-scale industrial production can be achieved. According to the high-purity doping porous silicon ball prepared in the method, the shapes of holes are regular, the holes are uniformly distributed and honeycomb-shaped, the shape of the silicon ball is regular, and the method can be widely used in the field of lithium batteries, solar batteries, semi-conductors, sensors and the like.

Description

technical field

[0001] The invention relates to the field of preparation of porous silicon materials, in particular to a process for preparing honeycomb-shaped porous silicon balls with controllable structure by using doped silicon balls at a certain temperature and a certain reaction time through a certain ratio of chemical etching solution method. Background technique

[0002] Porous silicon material has unique optoelectronic properties and large specific surface area so that it can be used in various detectors, biological microsensors, optoelectronic nano-devices, energy storage materials and other fields, especially as the anode material of lithium batteries has attracted much attention in recent years. Compared with traditional negative electrode materials, silicon has an ultra-high theoretical specific capacity (4200mAh / g) and a low delithiation potential (<0.5V), and it is difficult to cause lithium precipitation on the surface during charging, and its safety perfo...

Examples

Embodiment 1

[0036] This embodiment provides a method for preparing nanoporous silicon using doped silicon spheres. When using doped silicon spheres as a raw material, chemical etching is used to prepare nanoporous silicon. The specific steps are as follows:

[0037] 1) The boron doping concentration is selected to be 5.09×10 19 atoms / cm 3 (Conductivity 0.002~0.0025Ω·cm) P-type single crystal silicon master alloy is used as raw material, processed by pulse discharge method, processing parameters are: open circuit voltage 100V; peak current 5A; pulse width 50μs; duty ratio 1:2, The working fluid is deionized water, and the electrodes are copper electrodes. Process and collect doped silicon spheres, the particle size range of silicon spheres is 0.1-2 μm, the size is concentrated at 1 μm, and the concentration is greater than 90%.

[0038] 2) Measure 10g of silicon spheres as the base material;

[0039] 3) Clean the surface of the silicon ball with a chemical solution, the solution is 5% h...

Embodiment 2

[0050] This embodiment provides a method for preparing nanoporous silicon using doped silicon spheres. When using doped silicon spheres as a raw material, chemical etching is used to prepare nanoporous silicon. The specific steps are as follows:

[0051] 1) The phosphorus doping concentration is selected as 2.02×10 15 atoms / cm 3 N-type single crystal silicon ingot (conductivity 1~3Ω·cm) is used as raw material, processed by pulse discharge method, processing parameters are: open circuit voltage 150V; peak current 10A; pulse width 100μs; duty ratio 1:5, working fluid For deionized water, the electrode is a copper electrode. Process and collect doped silicon spheres, the particle size range of silicon spheres is 1-10 μm, the size is concentrated at 5 μm, and the concentration is greater than 90%.

[0052] 2) Measure 10g of silicon spheres as the base material;

[0053] 3) Clean the surface of the silicon ball with a chemical solution, the solution is 10% hydrofluoric acid sol...

technical field

[0001] The invention relates to the field of preparation of porous silicon materials, in particular to a process for preparing honeycomb-shaped porous silicon balls with controllable structure by using doped silicon balls at a certain temperature and a certain reaction time through a certain ratio of chemical etching solution method. Background technique

[0002] Porous silicon material has unique optoelectronic properties and large specific surface area so that it can be used in various detectors, biological microsensors, optoelectronic nano-devices, energy storage materials and other fields, especially as the anode material of lithium batteries has attracted much attention in recent years. Compared with traditional negative electrode materials, silicon has an ultra-high theoretical specific capacity (4200mAh / g) and a low delithiation potential (<0.5V), and it is difficult to cause lithium precipitation on the surface during charging, and its safety perfo...

Examples

Embodiment 1

[0036] This embodiment provides a method for preparing nanoporous silicon using doped silicon spheres. When using doped silicon spheres as a raw material, chemical etching is used to prepare nanoporous silicon. The specific steps are as follows:

[0037] 1) The boron doping concentration is selected to be 5.09×10 19 atoms / cm 3 (Conductivity 0.002~0.0025Ω·cm) P-type single crystal silicon master alloy is used as raw material, processed by pulse discharge method, processing parameters are: open circuit voltage 100V; peak current 5A; pulse width 50μs; duty ratio 1:2, The working fluid is deionized water, and the electrodes are copper electrodes. Process and collect doped silicon spheres, the particle size range of silicon spheres is 0.1-2 μm, the size is concentrated at 1 μm, and the concentration is greater than 90%.

[0038] 2) Measure 10g of silicon spheres as the base material;

[0039] 3) Clean the surface of the silicon ball with a chemical solution, the solution is 5% h...

Embodiment 2

[0050] This embodiment provides a method for preparing nanoporous silicon using doped silicon spheres. When using doped silicon spheres as a raw material, chemical etching is used to prepare nanoporous silicon. The specific steps are as follows:

[0051] 1) The phosphorus doping concentration is selected as 2.02×10 15 atoms / cm 3 N-type single crystal silicon ingot (conductivity 1~3Ω·cm) is used as raw material, processed by pulse discharge method, processing parameters are: open circuit voltage 150V; peak current 10A; pulse width 100μs; duty ratio 1:5, working fluid For deionized water, the electrode is a copper electrode. Process and collect doped silicon spheres, the particle size range of silicon spheres is 1-10 μm, the size is concentrated at 5 μm, and the concentration is greater than 90%.

[0052] 2) Measure 10g of silicon spheres as the base material;

[0053] 3) Clean the surface of the silicon ball with a chemical solution, the solution is 10% hydrofluoric acid sol...

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