Quantum Dot Luminophore Recycles Reflected Blue Light
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Solution Overview
Problem
Commercial phosphors used in LED components suffer from poor thermal stability and are difficult to synthesize, and surface-modified quantum dot luminophores exhibit light re-absorption issues, leading to low light conversion efficiency and emission intensity.
Innovation Solution
A quantum dot luminophore comprising a luminescent core, a spacer layer, and a plurality of quantum dots is designed to emit red and green lights after being excited by blue light, with the quantum dots surrounding the luminescent core to recycle reflected blue light and reduce light re-absorption, thereby enhancing light conversion efficiency and emission intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If surface-modified quantum dot luminophores are used to replace commercial phosphors, then thermal stability is improved, but light re-absorption occurs leading to low conversion efficiency
Solution Approach 1:
The luminophore is segmented into distinct functional layers: a quantum dot layer for light absorption and conversion, and a phosphor layer for complementary light emission. This segmentation prevents light re-absorption by spatially separating the two phosphor materials, thereby maintaining high conversion efficiency while preserving thermal stability benefits.
Solution Approach 2:
A barrier layer is introduced as an intermediary between the quantum dot luminophore and the phosphor powder. This barrier layer prevents direct contact and light re-absorption between the two materials, allowing each to function independently at optimal performance levels.
2Illumination intensity
If quantum dots are positioned at lower positions to be excited by blue light, then green light emission is achieved, but red light absorption by higher positioned quantum dots causes poor light mixing
Solution Approach 1:
The luminophore is divided into vertically separated functional zones: quantum dots in a lower layer for green light emission, and phosphor powder in an upper layer for red light emission. This vertical segmentation eliminates light re-absorption issues while maintaining effective light mixing through the layered structure.
Solution Approach 2:
The patent transitions from a horizontal arrangement where quantum dots are dispersed throughout to a vertical layered structure. By organizing materials in distinct vertical layers with the quantum dot layer at the bottom and phosphor layer at the top, the patent achieves both effective light emission and proper light mixing without re-absorption losses.
3Illumination intensity
If red and green phosphors are used in PC-LED, then white light with good color rendering is produced, but manufacturing cost increases
Solution Approach 1:
The quantum dot luminophore serves multiple functions simultaneously: it acts as both the blue light converter (emitting green light) and the thermal stabilizer, while also serving as the structural base for the phosphor layer. This multi-functionality eliminates the need for separate phosphor materials, reducing manufacturing complexity and cost.
Solution Approach 2:
The patent creates a composite luminophore structure combining quantum dots and phosphor powder in a single integrated component. This composite structure achieves both the color rendering benefits of multiple phosphors and the thermal stability of quantum dots, while simplifying the manufacturing process compared to using separate phosphor materials.
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 quantum dot luminophore increases light conversion efficiency and emission intensity by recycling reflected blue light and reducing light loss, providing a more stable and efficient alternative to commercial phosphors in LED components.
Implementation Method 1
the luminescent core is designed to emit a red light after being excited by an incident blue light
Implementation Method 2
the quantum dots are configured to irradiate a green light by the illumination of the blue light and/or the red light
Implementation Method 3
the quantum dots are arranged to cover or surround the luminescent core for solving the light re-absorption. By such arrangement, even though part of incident blue light (10-30%) may be reflected by the luminescent core made of phosphor material, the reflected blue light still can also be recycled by the quantum dots surrounding the luminescent core
Data Source
AI summary
A quantum dot luminophore comprising at least one luminescent core, a spacer layer, an encapsulation layer, and a plurality of quantum dots is disclosed. The luminescent core is designed to emit a red light after being excited by an incident blue light, and the quantum dots are configured to irradiate a green light by the illumination of the blue light and/or the red light. In the present invention, the quantum dots are particularly used to cover or surround the luminescent core for solving the light re-absorption. By such arrangement, even though part of incident blue light (about 10-30%) may be reflected by the luminescent core made of phosphor materials, the reflected blue light still can also be recycled by the quantum dots surrounding the luminescent core, such that the light conversion efficiency and emission intensity of the luminescent core are hence increased because the loss of blue light is decreased.