Core-Shell Silicate Luminescent Materials for LED Efficiency
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Solution Overview
Problem
Current silicate phosphor powders used in white light LEDs have low luminous efficiency and color purity, limiting their application in lighting and display fields.
Innovation Solution
A metal nanoparticles doped silicate luminescent material with a core-shell structure is developed, where metal nanoparticles such as Ag, Au, Pt, or Cu are coated with a silicate shell, enhancing internal quantum efficiency and luminous intensity, and the preparation method involves a controlled synthesis process to achieve a spherical profile with improved bulk density and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If silicate phosphor powder is used as yellow phosphor, then color purity is improved, but luminous efficiency deteriorates
Solution Approach 1:
The patent creates a composite structure by coating metal nanoparticles (Ag, Au, Pt, Pd, or Cu) with a silicate shell to form core-shell structured luminescent materials. This composite structure combines the optical properties of metal nanoparticles with the luminescent characteristics of silicate, achieving both high color purity and improved luminous efficiency that neither material alone can provide
Solution Approach 2:
The patent applies local quality modification by creating a core-shell structure where the metal nanoparticle core provides plasmonic enhancement for luminous efficiency while the silicate shell maintains color purity. The different regions of the composite material have specialized functions that together resolve the contradiction between color purity and luminous efficiency
2Loss of energy
If metal nanoparticles are coated with silicate shell, then internal quantum efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent employs preliminary action by first synthesizing metal nanoparticle colloids with controlled sizes and properties before coating them with the silicate shell. This pre-preparation of the core structure simplifies the overall manufacturing process by separating the synthesis steps and allowing optimization of each component independently
Solution Approach 2:
The patent uses an intermediary coating process where metal nanoparticles are first prepared in colloidal form with surface modifiers, then coated with silicate shell through controlled hydrolysis and condensation reactions. The intermediary colloidal state serves as a bridge between metal synthesis and ceramic shell formation, simplifying the integration of these otherwise incompatible materials
3Ease of manufacture
If conventional synthesis methods are used, then manufacturing process is simple, but synthesis temperature is high and environmental friendliness deteriorates
Solution Approach 1:
The patent applies parameter changes by conducting the silicate shell formation at lower temperatures (hydrolysis and condensation at ambient to moderate temperatures) compared to conventional high-temperature ceramic processing. This temperature reduction improves environmental friendliness while maintaining process simplicity through solution-based chemistry rather than high-energy thermal processing
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 core-shell structure significantly enhances the luminous intensity and stability of the silicate luminescent material, improving display effects and reducing synthesis temperature, making the process simpler, more environmentally friendly, and easier to control, with broad production prospects.
Implementation Method 1
metal NANO particles doped with silicate luminescent materials... the core-shell structure significantly enhances the luminous intensity
Implementation Method 2
coating SiO2 nanospheres... silicate luminescent material... excitation spectrum of the silicate phosphor powder is wider
Implementation Method 3
a metal salt solution, an additive and a reductant together are mixed together and react with each other to obtain a metal nanoparticle colloid
Implementation Method 4
an absolute ethanol, a deionized water, an aqueous ammonia, and a tetraethyl orthosilicate are added to the solution to prepare a coating SiO2 nanospheres
Data Source
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AI summary
Metal nano particles doped with silicate luminescent materials and preparation methods thereof are provided. The luminescent materials are represented by the general formula: (Sr1-x-yAxEuy)3SiO5:Dz@Mn, wherein A is one or two selected from alkaline-earth metal elements, D is F or Cl, @ is for coating, M is one or two selected from Ag, Au, Pt, Pd or Cu metal nano particles, 0≤x≤0.5, 0.001< y ≤ 0.15, and 0 ≤ z ≤ 0.5. n is a molar ratio of metal nano particles to the silicon element, wherein 0 < n≤0.01. Compared to the luminescent materials in the art, the said luminescent materials have higher internal quantum efficiency, luminous intensity and stability, therefore they are appropriate to be used in coating technique and improve the visual effect.