Phosphor-Functionalized Nanoparticles for LED Light Extraction
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Solution Overview
Problem
Conventional phosphors used in white light-emitting diodes (LEDs) face limitations due to resource depletion of rare-earth elements, difficulty in color tuning, and non-uniform dispersion within polymer resins, leading to reduced optical efficiency and luminous performance.
Innovation Solution
Phosphor-functionalized nanoparticles with an inorganic core and bimodal surface polymer brushes, including long-chain and short-chain polymers, where organic phosphors are bonded to the core or short-chain polymers, providing controlled dispersion and enhanced light conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional inorganic phosphors are mixed in the form of powders with resin, then the phosphor can be applied to LED light conversion, but scattering leads to significantly reduced optical efficiency
Solution Approach 1:
The patent creates a composite material system where inorganic phosphor particles are integrated with organic polymers to form phosphor-functionalized nanoparticles. The inorganic core provides phosphor functionality while the organic polymer shell improves dispersion compatibility with resin matrices, reducing scattering and enhancing optical efficiency.
Solution Approach 2:
The patent changes the physical and chemical parameters of the phosphor by functionalizing it with polymer brushes. This modification transforms the phosphor from a simple powder particle to a complex nanoparticle with controlled size, surface properties, and molecular weight characteristics, enabling uniform dispersion and reduced scattering.
2Reliability
If conventional inorganic phosphors are used, then light conversion can be achieved, but resource depletion of rare-earth elements limits application
Solution Approach 1:
The patent creates a universal phosphor platform where the inorganic core can be various rare-earth or non-rare-earth phosphors, while the organic polymer shell provides universal functionality for dispersion, stability, and potential additional properties like flexibility or biocompatibility. This multi-functional design expands material options beyond traditional inorganic phosphors.
3Adaptability or versatility
If conventional inorganic phosphors are used, then light conversion is possible, but difficulty in color tuning limits performance optimization
Solution Approach 1:
The patent applies local quality by separating the color-determining function (inorganic core) from the property-tuning function (organic polymer shell). The core composition controls emission color, while the shell properties can be independently optimized for dispersion, stability, or other functionalities, enabling precise color tuning without compromising other performance aspects.
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 solution enables improved light extraction efficiency, homogenous dispersion, and additional functionalities like color conversion and conductivity, resulting in higher luminous efficiency and better color rendering for LEDs.
Implementation Method 1
a wavelength converting phosphor which absorbs a portion of light emitted from the diode and undergoes secondary emission at a longer wavelength
Implementation Method 2
one or more organic phosphors bonded to at least one of the inorganic nanoparticle core and one or more of the plurality of short-chain polymers
Data Source
AI summary
Provided is a phosphor-functionalized nanoparticle that includes an inorganic nanoparticle core; surface polymer brushes that include a plurality of long-chain polymers bonded to the surface of the inorganic nanoparticle core, said long-chain polymers each having molecular weight greater than 500, and a plurality of short-chain polymers bonded to the surface of the inorganic nanoparticle core, said short-chain polymers each having molecular weight less than 0.5 times the average molecular weight of the long-chain polymers; and one or more organic phosphors bonded to at least one of the inorganic nanoparticle core and one or more of the plurality of short-chain polymers. Graft density of the short-chain polymers on the surface of the inorganic nanoparticle core (σSC) is greater than graft density of the long-chain polymers on the surface of the inorganic nanoparticle core (σLC). Also provided are polymer matrices, LED's, optical systems, lighting devices, and fixtures that include the inventive nanoparticle.