Mesa Micro-LED Bottom N-Contact Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing micro-LEDs have limited light extraction efficiency and density due to the placement of the n-contact on the side, which restricts the area of light emission and increases production complexity and cost.
Innovation Solution
A mesa-shaped micro-LED with the n-contact positioned at the bottom, allowing for a transparent conductive oxide layer that enhances light emission and reduces production complexity by eliminating the need for extended n-layer extensions, thereby increasing light extraction efficiency and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the n-contact is formed on the side of the mesa structure, then the electrical connection is established, but the light extraction area is reduced and production complexity increases
Solution Approach 1:
The patent inverts the conventional placement of the n-contact from the side of the mesa structure to the bottom surface. This inversion allows the n-contact to be positioned underneath the quantum well structure, eliminating the need for lateral extensions and enabling light to be extracted from the entire bottom surface area, thereby increasing light extraction efficiency while simplifying the manufacturing process
Solution Approach 2:
The patent transitions the n-contact placement from a lateral (2D) position on the mesa side to a vertical (3D) position at the bottom surface. This dimensional change allows the n-contact to be integrated into the vertical stack beneath the quantum well, enabling full bottom-surface light emission and reducing the need for complex lateral routing and extended structures
2Illumination intensity
If the n-contact is placed on the extended n-type layer, then electrical connection is achieved, but the area for light emission is limited
Solution Approach 1:
By inverting the n-contact placement to the bottom surface and positioning it beneath the quantum well, the patent enables light to be emitted from the entire bottom surface area of the mesa structure. This eliminates the restriction where only portions of the extended n-layer could emit light, thereby increasing both the total emission area and the light density per unit area
3Ease of manufacture
If the n-contact is formed on the side with extended n-layer, then electrical connection is established, but production time and cost increase
Solution Approach 1:
Inverting the n-contact to the bottom surface eliminates the need for complex lateral extensions of the n-layer beyond the mesa structure. This simplifies the fabrication process by reducing the number of patterning and deposition steps required, thereby decreasing production time and cost while maintaining proper electrical connection
Solution Approach 2:
The patent merges the n-contact formation with the bottom surface of the mesa structure, eliminating the need for separate extended n-layer regions. This consolidation simplifies the manufacturing process by reducing the number of discrete structural elements that must be fabricated and aligned, thereby reducing production complexity and time
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 increases light extraction relative to the size of the micro-LED, enhances light density in multi-LED arrangements, and simplifies the production process, reducing costs and time.
Implementation Method 1
light is usually generated through recombination of electrons, originating from an n-type doped semiconductor layer, and holes originating from a p-type doped semiconductor layer
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A light emitting diode (LED) with a first electrical contact at the top of the LED and a second electrical contact at the bottom of the LED. Layers of materials are formed on a substrate. The layers of materials include a first semiconductor layer, a second semiconductor layer, and a light emitting layer between the first and second semiconductor layers for producing light responsive to passing current through the light emitting layer. The formed layers of material are shaped into at least one semiconductor structure. A first electrical contact is formed on a top of the semiconductor structure, and a second electrical contact is formed at a bottom of the semiconductor structure. The second electrical contact is at least partially transparent.