Monolithic Multi-Wavelength Micro-LED Structure for Full-Color Displays
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Solution Overview
Problem
The commercialization of full-color micro-LED displays is hindered by the complexity of the assembly process, which requires precise alignment of red, green, and blue micro-LEDs grown on different wafers, leading to increased production costs and reduced efficiency.
Innovation Solution
A multi-wavelength light-emitting device is manufactured using a monolithic integration method where RGB micro-LEDs are grown on the same substrate, with varying porosity nanopores in the semiconductor layers to control strain and emission wavelengths, eliminating the need for a color conversion layer and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If red, green, and blue micro-LEDs are grown on different wafers and assembled on the same TFT, then full color display is achieved, but the transfer or assembly process becomes complicated and limits resolution
Solution Approach 1:
The patent merges the growth of red, green, and blue micro-LEDs onto a single substrate instead of assembling separate wafers. This is achieved by forming a multi-quantum well structure with different InGaN layers (containing InxGa1-xN, InyGa1-yN, and InzGa1-zN where x>y>z) that emit different wavelengths, eliminating the need for complex multi-wafer assembly processes while maintaining full color display capability
Solution Approach 2:
The patent applies local quality by creating distinct active regions within the single micro-LED structure that emit different colors. The multi-quantum well structure has spatially varying composition (different In content in different layers) that locally determines emission wavelength, allowing red, green, and blue emission zones to coexist in one device without requiring separate wafers
2Manufacturing precision
If precise alignment for each pixel is required in multi-wafer assembly, then full color micro-LED display is obtained, but production efficiency is lowered and production cost increases
Solution Approach 1:
By combining all color emissions into a single monolithic micro-LED growth process on one substrate, the patent eliminates the need for precise alignment and transfer operations between multiple wafers. The single-step growth approach maintains manufacturing precision while dramatically improving production efficiency by removing the assembly bottleneck
Solution Approach 2:
The patent performs preliminary action by pre-forming the complete multi-color active layer structure with all necessary quantum well layers and composition gradients during the initial growth process. This preliminary structuring eliminates the need for subsequent alignment and assembly operations, as all color-emitting regions are already in their final positions before device completion
3Manufacturing precision
If monolithic multicolor manufacturing technology is used for micro-LED chip size reduction and resolution increase, then resolution is improved, but the manufacturing process becomes complicated due to different growth conditions for each R/G/B
Solution Approach 1:
The patent uses parameter changes by systematically varying the Indium content (x, y, z where x>y>z) in the InGaN layers to control emission wavelength. By changing this compositional parameter across different layers while maintaining a unified growth process, the patent achieves multi-color emission without requiring separate growth conditions for each color, thus improving resolution while managing manufacturing complexity
Solution Approach 2:
The patent employs composite materials by creating a multi-layer InGaN structure where each layer has a different composition (InxGa1-xN, InyGa1-yN, InzGa1-zN). This composite approach allows different optical properties (emission wavelengths) to be achieved within a single material system grown under unified conditions, enabling high-resolution monolithic multicolor manufacturing
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 allows for the monolithic production of micro-LEDs with different colors, reducing production complexity and costs while maintaining high resolution and efficiency, enabling the creation of high-resolution, full-color displays without the need for additional color conversion layers.
Implementation Method 1
varying porosity nanopores in the semiconductor layers to control strain and emission wavelengths
Data Source
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AI summary
A multi-wavelength light-emitting device configured to emit light of a first wavelength, light of a second wavelength, and a third wavelength, includes a substrate, a first type semiconductor layer provided on the substrate, an active layer provided on the first type semiconductor layer, a second type semiconductor layer provided on the active layer, and an electrode provided on the second type semiconductor layer. The active layer includes a first active area configured to emit the light of the first wavelength, a second active area configured to emit the light of the second wavelength, and a third active area configured to emit the light of the third wavelength.