Metal-Based Particle Assembly for Plasmon Resonance
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Solution Overview
Problem
Conventional plasmonic materials, such as silver nanoparticles, provide a weak enhancement effect via localized plasmon resonance, which is not sufficient to significantly enhance emission in light emitting devices or improve conversion efficiency in photoelectric conversion devices.
Innovation Solution
A metal-based particle assembly comprising 30 or more metal particles separated in two dimensions, with specific size and shape characteristics, including an average particle diameter of 200 to 1600 nm, an average height of 55 to 500 nm, and an aspect ratio of 1 to 8, exhibiting intense plasmon resonance and extended range plasmon enhancement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If large-size metal particles (approximately 500 nm diameter) are used to increase the number of surface free electrons, then the theoretical luminous efficiency reaches approximately one, but the actual emission enhancement effect is weak because dipole-type localized plasmon is not easily generated
Solution Approach 1:
The invention divides a large metal particle into multiple smaller metal particles (3-1000 particles per superparticle, each 20-500 nm diameter). This segmentation creates multiple surfaces that can support dipole-type localized plasmons while maintaining a large effective number of free electrons, thus resolving the contradiction between having enough free electrons and generating strong plasmon resonance.
Solution Approach 2:
The invention creates a composite structure where multiple metal particles are assembled into a superparticle configuration. This composite approach combines the advantages of small particles (strong dipole plasmon resonance) with the advantages of large particles (large number of free electrons), achieving both high luminous efficiency and strong emission enhancement effect.
2Object-generated harmful factors
If small metal nanoparticles are used to generate dipole-type localized plasmon resonance, then emission enhancement is achieved, but the enhancement effect is rather weak and not sufficient for significant improvement in light emitting devices
Solution Approach 1:
The invention merges multiple small metal particles into a superparticle assembly that functions as a single enhanced plasmonic unit. By combining 3-1000 small particles (each contributing dipole plasmon resonance) into one superparticle structure with effective diameter of 1-10 μm, the total number of free electrons increases while maintaining strong collective plasmon resonance, thus overcoming the weakness of individual small particles.
Solution Approach 2:
The invention transitions from considering single particle properties to assembly-level properties by arranging multiple particles in specific geometric configurations (face-centered cubic, body-centered cubic, simple cubic, or random close packing). This dimensional transition from particle scale to assembly scale creates new plasmonic properties that are stronger than the sum of individual particles.
3Use of energy by moving object
If metal particles with specific size and shape are used to achieve intense plasmon resonance, then luminous efficiency is improved, but the device structure becomes more complex requiring precise control of particle diameter, height, and aspect ratio
Solution Approach 1:
The invention establishes specific parameter ranges for metal particles (diameter: 20-500 nm, height: 55-500 nm, aspect ratio: 1-8) and assembly configuration (3-1000 particles per superparticle, inter-particle distance: 1-2 μm) to optimize plasmon resonance. By defining these parameter ranges, the invention makes the complex structure controllable and reproducible while achieving intense plasmon resonance and high luminous efficiency.
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 metal-based particle assembly achieves significantly more intense plasmon resonance and extended range plasmon enhancement, leading to improved luminous efficiency and conversion efficiency in optical devices like light emitting devices and solar cells.
Implementation Method 1
localized plasmon resonance is in particular expected for application. Plasmon is a compressional wave of free electrons that arises by collective oscillation of the free electrons in a metallic nanostructure.
Data Source
AI summary
There is provided a metal-based particle assembly comprising 30 or more metal-based particles separated from each other and disposed in two dimensions, the metal-based particles having an average particle diameter in a range of from 200 to 1600 nm, an average height in a range of from 55 to 500 nm, and an aspect ratio, as defined by a ratio of the average particle diameter to the average height, in a range of from 1 to 8, wherein the metal-based particle assembly has in an absorption spectrum for a visible light region a maximum wavelength of a peak at a longest side in wavelength, and an absorbance at the maximum wavelength is higher as compared with that of a reference metal-based particle assembly, on the premise that the numbers of the metal-based particles are the same. The metal-based particle assembly of the present invention presents significantly intense plasmon resonance.