Quantum Dot Luminescent Material for Uniform LED Light Emission
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Solution Overview
Problem
The challenge lies in achieving uniform distribution and high-temperature endurance of quantum dots in luminescent materials for improved light-emitting devices, as well as finding a cost-effective solution that balances color rendering and saturation when using both quantum dots and phosphors in LEDs.
Innovation Solution
A luminescent material comprising particles with quantum dots and phosphors, where the particles have an average diameter of 0.06 μm to 30 μm, allowing for efficient dispersion and adsorption of quantum dots, and a sealing layer to enhance stability and prevent aggregation, combined with a suitable core and phosphor composition to achieve uniformity and high luminescence efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum dots are directly dispersed in solvent and coated, then the luminescent feature is maintained, but the quantum dots are hard to be evenly distributed and gather into micron-sized clusters causing poor light-emitting uniformity
Solution Approach 1:
The patent introduces polymer particles as an intermediary carrier to disperse quantum dots. The quantum dots are adsorbed onto the surface of polymer particles, which act as a mediator between the quantum dots and the solvent matrix. This intermediary structure prevents direct aggregation of quantum dots while maintaining their luminescent properties, and enables uniform distribution throughout the coating layer.
Solution Approach 2:
The patent creates local concentration zones of quantum dots on the surface of individual polymer particles rather than attempting uniform distribution at the molecular level. Each polymer particle serves as a localized carrier with quantum dots distributed on its surface, creating a heterogeneous structure where quantum dots are evenly spaced at the macroscopic level while maintaining high local concentration on particle surfaces for optimal luminescence.
2Reliability
If quantum dots are used in liquid form, then the luminescent feature is preserved, but the application difficulty increases and processing design becomes complex
Solution Approach 1:
The patent changes the physical state parameter of the quantum dot composition from liquid suspension to solid powder form. By adsorbing quantum dots onto polymer particles and then drying the solvent, the material transforms into a free-flowing powder that can be easily handled, stored, and applied using conventional powder coating techniques, while the quantum dots retain their luminescent properties in the dried state.
Solution Approach 2:
The patent segments the quantum dot-ligand system by attaching quantum dots to individual polymer particle surfaces rather than maintaining them as a continuous liquid suspension. This segmentation into discrete solid particles eliminates the complexity of liquid handling while preserving the quantum dot properties, enabling simple powder-based processing.
3Reliability
If quantum dots with ligands are used, then the luminescent feature is achieved, but the high-temperature endurance becomes poor
Solution Approach 1:
The patent introduces polymer particles as a thermal buffer intermediary between the quantum dots and the high-temperature environment. The polymer matrix provides thermal insulation and mechanical support, protecting the temperature-sensitive quantum dot-ligand interfaces from direct thermal stress while allowing the luminescent properties to be maintained at elevated operating temperatures.
4Ease of manufacture
If phosphor is used instead of quantum dot, then the manufacturing cost is reduced, but the color rendering becomes poor
Solution Approach 1:
The patent merges phosphor particles with quantum dot-polymer composite particles to create a hybrid luminescent material. This combination allows the system to benefit from both phosphor (lower cost, broader emission) and quantum dot (superior color rendering, narrow emission) properties, achieving a balance between manufacturing cost and color rendering performance.
Solution Approach 2:
The patent creates a composite luminescent material consisting of phosphor particles combined with quantum dots adsorbed on polymer particles. This composite structure enables synergistic effects where phosphor provides cost-effectiveness and quantum dots enhance color saturation and rendering, delivering a material that outperforms either component alone in terms of overall performance-to-cost ratio.
5Reliability
If phosphor and quantum dot are used together in LED, then the color rendering and saturation are improved, but the mixing uniformity and self-absorption problems occur due to huge size difference
Solution Approach 1:
The patent resolves the mixing uniformity issue by transitioning from two-dimensional planar mixing to three-dimensional spatial separation. Phosphor particles and quantum dot-polymer composite particles are mixed as discrete three-dimensional objects with sufficient size difference to prevent quantum dot self-absorption, while the polymer particle size (0.1-10 μm) provides a intermediate scale that ensures uniform distribution without causing aggregation.
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
This approach results in improved light-emitting uniformity, enhanced high-temperature resistance, and cost-effective production of LEDs with superior color rendering and saturation, effectively addressing the limitations of existing technologies.
Implementation Method 1
The quantum dot can emit a light having a narrow full width at half maximum (FWHM), and have high luminescence efficiency and a wide absorption spectrum
Implementation Method 2
The quantum dot can emit a light having a narrow full width at half maximum (FWHM), and have high luminescence efficiency
Implementation Method 3
a fluorescence luminescent material and a light emitting device and a display device using the same
Implementation Method 4
a conventional known phosphor applied in a light emitting diode (LED)
Data Source
AI summary
A luminescent material, a light emitting device, and a display device are disclosed. The luminescent material includes particles and a phosphor. The particles include quantum dots and have an average diameter of 0.06 μm to 30 μm.