Dual-Surface Nanoantenna Phosphor Layout for Fluorescence Extraction
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Solution Overview
Problem
Existing illumination devices face challenges in extracting fluorescence efficiently due to the fluorescence propagating inside the wavelength conversion layer and being absorbed or emitted from unintended surfaces, leading to reduced light extraction efficiency.
Innovation Solution
A wavelength conversion device with a flat plate-shaped phosphor portion, a first nanoantenna group, and a translucent body portion, along with a second nanoantenna group, is designed to enhance fluorescence extraction by controlling the diffraction angles and reflections using nanoantennas arranged at specific pitches and shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single nanoantenna array is used on one surface of the phosphor layer, then the device structure is simple, but fluorescence extraction efficiency is low due to propagation losses and absorption
Solution Approach 1:
The single nanoantenna array is divided into two separate arrays positioned on opposite surfaces of the phosphor layer. The first nanoantenna group is arranged on the lower surface while the second nanoantenna group is arranged on the upper surface. This segmentation allows fluorescence to be extracted from both surfaces simultaneously, reducing propagation losses and improving overall extraction efficiency without requiring an overly complex single-structure design
Solution Approach 2:
The solution transitions from a two-dimensional single-surface nanoantenna arrangement to a three-dimensional dual-surface configuration. By placing nanoantenna groups on both the lower and upper surfaces of the phosphor layer, the system utilizes the vertical dimension to create multiple extraction pathways, thereby improving fluorescence extraction efficiency while maintaining structural feasibility
2Loss of energy
If nanoantennas are arranged at a fixed pitch to control diffraction, then light extraction efficiency improves, but the device becomes sensitive to wavelength variations
Solution Approach 1:
The first and second nanoantenna groups are designed with different local characteristics, including different pitches and potentially different geometries. The first nanoantenna group on the lower surface has a pitch optimized for incident angles from below, while the second nanoantenna group on the upper surface has a pitch optimized for incident angles from above. This local differentiation allows each group to effectively handle specific wavelength ranges and incident angles, improving overall wavelength adaptability while maintaining high extraction efficiency
Solution Approach 2:
The system employs different pitch parameters for the two nanoantenna groups to adapt to different operational conditions. By varying the pitch between the first and second nanoantenna groups, the device can optimize performance for different wavelengths and incident angles, thereby improving wavelength adaptability while maintaining efficient light extraction across a broader spectrum
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 device improves light extraction efficiency by increasing the proportion of fluorescence emitted at narrow angles, enhancing the overall performance of the illumination device.
Implementation Method 1
a flat plate-shaped phosphor portion (24), a first nanoantenna group (22A)
Implementation Method 2
The respective plurality of first nanoantennas are made of metals arranged at a first pitch
Data Source
AI summary
A wavelength conversion device includes a flat plate-shaped phosphor portion, a first nanoantenna group, a translucent body portion, and a second nanoantenna group. The flat plate-shaped phosphor portion includes a phosphor to be excited by an excitation light to emit a fluorescence. The first nanoantenna group is provided at a lower surface side of the phosphor portion and includes a plurality of first metal nanoantennas arranged at a first pitch. The translucent body portion is filled between adjacent first nanoantennas, formed on the lower surface of the phosphor portion to cover the lower surface of the phosphor portion, and made of a translucent material. The second nanoantenna group is provided on an upper surface of the phosphor portion and includes a plurality of second metal nanoantennas arranged at a second pitch on the upper surface of the phosphor portion.