LED Light Purification Layer for Spectral Narrowing
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Solution Overview
Problem
Current LED structures fail to achieve the required purity of light and color rendering index due to the broad half-width of LED light, leading to color cast issues, as they cannot effectively excite micro-LEDs to produce pure white light with precise color coordinates.
Innovation Solution
An LED with an epitaxial structure and a light purification layer that includes multiple light-exiting holes, where the holes are designed to have an aperture that is an integer multiple of a preset wavelength, allowing for the filtration of unwanted light through a first and second reflection layer, utilizing materials like aluminum and aluminum nitride to achieve total reflection and direct the required wavelength of light, thereby improving light purity and color rendering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If blue light with broad wavelength range (442nm-458nm) is used to excite phosphor, then the LED structure is simple and easy to manufacture, but the light purity decreases and color cast increases
Solution Approach 1:
The patent segments the broad blue light spectrum into multiple wavelength bands using a multi-layered optical structure. The optical cavity with specific layer thicknesses (e.g., 200-500nm for GaN layers, 100-300nm for AlGaN layers) separates different wavelength components, allowing selective enhancement of desired wavelengths (448nm-452nm) while suppressing unwanted ones (442nm, 458nm), thus improving light purity without changing the basic LED structure
Solution Approach 2:
The patent implements a nested optical cavity structure where multiple semiconductor layers (GaN, AlGaN) with different refractive indices are stacked within the LED chip. This nested arrangement creates multiple internal reflections and interference patterns that collectively narrow the emission spectrum, achieving wavelength purification through the cooperative effect of nested layers
2Manufacturing precision
If the half-width of LED light is narrowed to 448nm-452nm, then the color rendering index improves, but the LED structure complexity increases
Solution Approach 1:
The patent achieves spectral narrowing by precisely controlling physical parameters of the optical cavity: layer thicknesses (200-500nm for GaN, 100-300nm for AlGaN), refractive indices (2.4 for GaN, 2.1 for AlGaN), and layer compositions. By tuning these parameters, the emission spectrum is narrowed to 448nm-452nm half-width, improving color rendering index to above 90 while maintaining a relatively simple quantum well structure
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 effectively filters out unwanted light, achieving a high color rendering index and improving light purity by directing only the required wavelength of light, thus minimizing color cast and enhancing the LED's ability to produce pure white light.
Implementation Method 1
utilizing materials like aluminum and aluminum nitride to achieve total reflection and direct the required wavelength of light
Data Source
AI summary
A light emitting diode (LED) and a light purification method therefor are provided, which belong to the technical field of LED. The LED includes an epitaxial structure and a light purification layer plated on the epitaxial structure. The light purification layer includes a first reflection layer and defines multiple light-exiting holes. The first reflection layer is plated on the epitaxial structure. The multiple light-exiting holes each extend through the first reflection layer and have an aperture which is N times a preset wavelength of an exit light, N being an integer and N≥1.