Monolithic 3D and Flat LED Structure for Full-Color Microdisplays
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Solution Overview
Problem
The challenge lies in accurately aligning small semiconductor light-emitting diodes (LEDs) on a driving substrate for high-resolution color displays, as existing technologies face difficulties in achieving precise alignment and efficient multi-wavelength light emission, particularly in generating red light with high indium composition, which is crucial for full-color displays.
Innovation Solution
A monolithic light-emitting device is designed with a base semiconductor layer, a three-dimensional (3D) light-emitting structure, and a flat light-emitting structure, both utilizing a strain-relieving layer to alleviate lattice mismatch, allowing for the generation of multi-wavelength light, including blue, green, and red, by varying the indium composition and growth patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the size of LEDs is reduced to achieve high resolution, then the resolution of color displays is improved, but the alignment accuracy of LEDs on the driving substrate deteriorates
Solution Approach 1:
The patent merges multiple light-emitting structures (blue LED, green LED, red LED) into a single integrated device on one semiconductor substrate. This integration eliminates the need for separate alignment of multiple discrete LEDs, thereby maintaining high resolution while solving the alignment accuracy problem that arises when LEDs are miniaturized.
2Adaptability or versatility
If different types of LEDs (blue, green, red) are used for color display, then the color display capability is improved, but the alignment complexity and difficulty increase
Solution Approach 1:
The patent combines blue, green, and red light-emitting structures into a single monolithic device, enabling full color display capability while eliminating the complex alignment process that would be required if these different LED types were separate components.
Solution Approach 2:
The single semiconductor substrate serves multiple functions by integrating different light-emitting structures (blue, green, red LEDs) that can be selectively activated to produce various colors, thereby achieving multi-functionality without increasing alignment complexity.
3Quantity of substance
If the indium composition of the flat light-emitting structure is increased to generate longer wavelength light, then the wavelength range is improved, but the lattice mismatch between the base semiconductor layer and the light-emitting structure increases
Solution Approach 1:
The patent introduces a strain-relieving layer as an intermediary between the base semiconductor layer and the flat light-emitting structure with high indium composition. This intermediate layer accommodates the lattice mismatch, enabling the growth of high-indium-content structures that emit longer wavelength light without compromising manufacturing precision.
Solution Approach 2:
The patent changes the compositional parameter of the light-emitting structure by increasing indium composition to achieve longer wavelength emission. This parameter change is made possible through the strain-relieving layer that compensates for the resulting lattice mismatch.
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 configuration enhances the internal quantum efficiency, reduces crystal defects, and increases light emission efficiency, enabling the production of high-resolution displays with improved productivity and yield by integrating blue, green, and red light-emitting structures within a single device.
Implementation Method 1
the strain-relieving layer relieves lattice mismatch between the base semiconductor layer and the flat light-emitting structure
Implementation Method 2
a three-dimensional (3D) light-emitting structure on the base semiconductor layer, the 3D light-emitting structure including at least one semi-polar surface; a flat light-emitting structure on the base semiconductor layer, the flat light-emitting structure including a polar surface, wherein the flat light-emitting structure generates light
Data Source
AI summary
A light-emitting device includes a base semiconductor layer, a three-dimensional (3D) light-emitting structure, and a flat light-emitting structure formed in a flat shape, wherein the flat light-emitting structure generates light having a different wavelength than that of the 3D light-emitting structure. A strain-relieving layer relieving lattice mismatch between the base semiconductor layer and the flat light-emitting structure may be arranged on the base semiconductor layer in an area in which at least the flat light-emitting structure is formed.