Micro-LED Current Control via Segmented Opening Layer
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Solution Overview
Problem
Micro-light-emitting diodes (micro-LEDs) face challenges in achieving adequate brightness while maintaining efficiency and uniformity, as conventional methods result in high brightness and inefficient current distribution, making it difficult to miniaturize the emitting area without compromising manufacturing yield and handling.
Innovation Solution
Incorporating a current controlling layer with openings that limits the current flow to a specific area, allowing for a smaller light emitting region, increased current density, and improved uniformity, enabling miniaturization while maintaining manufacturing feasibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the emitting area of micro-LED is reduced to provide adequate brightness, then the brightness control is improved, but the manufacturing yield and handling become difficult
Solution Approach 1:
The patent divides the emitting area into multiple sub-emitting regions arranged in an array, where each region is controlled by a separate opening in the current controlling layer. This segmentation allows the total emitting area to be reduced while maintaining manufacturability, as each small region can be independently controlled and the overall structure remains compatible with standard manufacturing processes.
Solution Approach 2:
The patent applies local quality by creating non-uniform current distribution through the opening structure in the current controlling layer. The openings are strategically positioned to concentrate current flow into specific emitting regions, achieving high brightness in localized areas while keeping the overall device size manageable and compatible with manufacturing requirements.
2Length of moving object
If the emitting area of micro-LED is miniaturized, then the size reduction is achieved, but the current density uniformity and efficiency deteriorate
Solution Approach 1:
The emitting area is segmented into multiple sub-regions, each fed through a separate opening in the current controlling layer. This segmentation prevents current crowding effects that would occur in a single miniaturized emitting region, as the current is distributed through multiple pathways, maintaining uniformity and efficiency while achieving overall size reduction.
Solution Approach 2:
The patent transitions from a planar current distribution to a three-dimensional structure with openings penetrating through the current controlling layer. This dimensional change allows current to be injected from the top through the openings, creating a more uniform current density distribution throughout the emitting regions and improving efficiency while maintaining miniaturization.
3Ease of manufacture
If the current flow is distributed over a large area, then the manufacturing is easier, but the brightness and efficiency decrease
Solution Approach 1:
The current controlling layer with its opening structure creates local quality by concentrating current flow into specific emitting regions rather than distributing it uniformly across the entire device area. This local current concentration achieves high brightness and efficiency in the emitting regions while the overall device structure remains compatible with standard manufacturing processes.
Solution Approach 2:
The current controlling layer acts as an intermediary between the electrodes and the emitting regions. It mediates the current distribution by guiding current through the openings to the specific emitting areas, thereby achieving both good manufacturing compatibility and high brightness/efficiency in the emitting regions.
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 continuation of micro-LED miniaturization while ensuring acceptable yield rates, providing adequate brightness and increased efficiency by concentrating current density within a smaller emitting area, thus enhancing the operating stability and reliability of micro-LEDs.
Implementation Method 1
In an LED, when electrons and holes recombine across the semiconductor gap, the recombination energy is emitted in the form of photons and generates light. This recombination mechanism is the so-called radiative recombination.
Data Source
Figure 1
Figure 2A~2B
Figure 2C~2D
AI summary
A micro-light-emitting diode (micro-LED) (100A) includes a first type semiconductor layer (122), a second type semiconductor (124), a first current controlling layer (130), a first electrode (140), and a second electrode (150). The second type semiconductor layer and the first current controlling layer are joined with the first type semiconductor layer. The first current controlling layer has at least one opening (131) therein. The first electrode is electrically coupled with the first type semiconductor layer through the opening. The second electrode is electrically coupled with the second type semiconductor layer. At least one of the first electrode and the second electrode has a light-permeable part. A vertical projection of the first current controlling layer on said one of the first electrode and the second electrode overlaps with the light-permeable part. The light-permeable part is transparent or semi-transparent.