Low-Temperature Synthesis of Single-Crystal Spherical Silicon Nanoparticles
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Solution Overview
Problem
Existing methods for producing silicon nanoparticles fail to produce blue to orange fluorescence at high efficiency, are not monocrystalline and spherical, and are not suitable for industrial-scale production due to the use of hazardous chemicals or complex and inefficient processes.
Innovation Solution
A method involving the mixing and reaction of a silicon halide raw material liquid with a reduction liquid containing an anion of a condensed aromatic compound at low temperatures, using a fluid processing apparatus with rotating processing surfaces to produce monocrystalline and spherical silicon nanoparticles with an average diameter of 1 to 20 nm, which exhibit high fluorescence quantum efficiency upon excitation by light across a wide range of wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If commercially available silicon particles are used and treated with acids to remove oxide films, then silicon nanoparticles can be produced, but the particles are not monocrystalline and have poor fluorescence efficiency
Solution Approach 1:
The invention changes the fundamental parameter of silicon production from using commercially available particles to synthesizing silicon nanoparticles inorganic particles through controlled chemical reactions. This transforms the crystalline structure from polycrystalline to monocrystalline, achieving both high manufacturing precision and reliable fluorescence efficiency simultaneously.
Solution Approach 2:
The invention replaces the mechanical/chemical etching method (using hydrofluoric and nitric acids) with a controlled inorganic synthesis method. This substitution eliminates the need for harsh acid treatments that damage crystal structure, producing monocrystalline particles with intact fluorescence properties.
2Ease of manufacture
If acid substances are used to remove oxide films from silicon particles, then silicon nanoparticles can be produced, but the handling requires great care and industrial production is difficult
Solution Approach 1:
The invention converts the harmful effect of oxide films (which normally require hazardous acids to remove) into a beneficial feature by controlling their formation during synthesis. The oxide film is deliberately controlled to be thin and uniform, eliminating the need for hazardous acid treatments while maintaining particle stability.
Solution Approach 2:
The invention replaces expensive and hazardous acid chemicals with a controlled inorganic synthesis process that uses safer, more manageable reagents. This makes the production process safer for industrial implementation while maintaining high particle quality.
3Manufacturing precision
If pulse laser irradiation is used to produce silicon nanoparticles, then nanoparticles can be deposited on substrates, but the method requires expensive laser equipment and cannot produce particles at low cost
Solution Approach 1:
The invention replaces the expensive pulse laser system with a controlled inorganic chemical synthesis method. This substitution maintains precise particle size control through chemical stoichiometry and reaction conditions, while eliminating the need for costly laser equipment, making industrial production economically feasible.
4Temperature
If silicon nanoparticles are produced in organic solvent with reducing agents at low temperatures, then particles can be formed, but the produced particles are polycrystalline not monocrystalline and spherical
Solution Approach 1:
The invention changes the critical parameters of particle formation by controlling the inorganic synthesis conditions more precisely than conventional organic solvent methods. By optimizing reaction temperature, reagent ratios, and synthesis time, the method produces monocrystalline spherical particles at low temperatures, achieving both temperature efficiency and high manufacturing precision simultaneously.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The produced silicon nanoparticles achieve high fluorescence quantum efficiency from deep ultraviolet to visible light, are non-toxic, and can be used as electrode materials for solar cells and secondary ion batteries at high density, overcoming the limitations of previous methods.
Implementation Method 1
mixing and reacting a raw material liquid containing silicon halide with a reduction liquid containing an anion of a condensed aromatic compound
Implementation Method 2
using a fluid processing apparatus with rotating processing surfaces
Implementation Method 3
exhibit high fluorescence quantum efficiency upon excitation by light across a wide range of wavelengths
Implementation Method 4
produce blue to orange fluorescence at a high fluorescence quantum efficiency upon excitation by light
Data Source
AI summary
The present disclosure relates to a method of producing single-crystal spherical silicon nanoparticles which are monocrystalline and spherical and has an average particle diameter of 1 nm to 20 nm. The method includes a step of mixing and reacting a raw material liquid containing silicon halide with a reduction liquid containing an anion of a condensed aromatic compound produced from lithium, sodium or potassium and the condensed aromatic compound. The anion of the condensed aromatic compound is prepared by mixing the lithium, sodium or potassium and the condensed aromatic compound at a temperature of less than 0° C. The single-crystal spherical silicon nanoparticles produced by the method of the present invention can produce fluorescence from blue to red upon excitation by light in a wide range of wavelengths from deep ultraviolet light having a wavelength of 200 nm to 300 nm to visible light, and can increase the conventionally known fluorescence quantum efficiency of silicon nanoparticles from around 1% to 10% or more.