LED Module Dual-Protrusion Structure for Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light emitting diodes (LEDs) suffer from reduced light emission efficiency due to trapped light within the device, which is not effectively extracted to the outside.
Innovation Solution
A light emitting device with a substrate featuring a first protrusion pattern and a second protrusion pattern of different design and refractive index, positioned on a base layer, to enhance light extraction efficiency by diversifying the light reflection pattern and optimizing the epitaxial process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a single protrusion pattern is formed on the substrate, then the light extraction efficiency is improved to some extent, but light is still trapped inside the light emitting diode and light emission efficiency decreases
Solution Approach 1:
The invention divides the light extraction function into two separate protrusion patterns: a first protrusion pattern on the substrate and a second protrusion pattern on the base layer. This segmentation allows each pattern to contribute differently to light extraction, with the first pattern providing initial scattering and the second pattern providing additional extraction enhancement, thereby overcoming the limitation of a single pattern while managing complexity through functional division.
Solution Approach 2:
The invention adds a vertical dimension to the light extraction approach by placing the second protrusion pattern on the base layer rather than directly on the substrate. This creates a multi-layered optical path where light interacts with protrusion patterns at different heights and positions, effectively utilizing the vertical dimension to improve light extraction efficiency beyond what a single planar pattern could achieve.
2Loss of energy
If the second protrusion pattern has lower height and smaller pitch than the first protrusion pattern, then light extraction efficiency is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The manufacturing process is segmented into two distinct stages: first forming the first protrusion pattern on the substrate, then forming the second protrusion pattern on the base layer. This segmentation allows each pattern to be optimized independently for its specific function, with the second pattern's smaller pitch and lower height being precisely controlled during its formation stage, thereby managing manufacturing precision requirements through process division.
Solution Approach 2:
The first protrusion pattern is formed in advance on the substrate before the base layer is deposited and the second protrusion pattern is formed. This preliminary action establishes a foundation that guides subsequent processing, allowing the second pattern to be precisely positioned and formed with the required smaller pitch and lower height specifications without compromising overall alignment and precision.
3Loss of energy
If the second protrusion pattern has a higher fill factor than the first protrusion pattern, then light extraction efficiency is improved, but the device complexity increases
Solution Approach 1:
The invention applies different fill factor characteristics to different locations in the device structure: the first protrusion pattern on the substrate has a certain fill factor optimized for initial light scattering, while the second protrusion pattern on the base layer has a higher fill factor specifically optimized for enhancing light extraction in the region where light emerges from the active layer. This local optimization of fill factor at different positions improves overall light extraction efficiency while managing complexity through location-specific design.
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 improves light extraction efficiency and epitaxial process efficiency by reducing light trapping, increasing the fill factor, and utilizing refractive index changes to randomize light paths, thereby enhancing overall light emission.
Implementation Method 1
light extraction efficiency is intended to be improved based on a change in refractive index on a light path by configuring materials of the protrusion patterns in consideration of a relationship between refractive indices
Data Source
AI summary
A light emitting device is provided that includes: a substrate including a first protrusion pattern on its top surface; a base layer formed on a top of the substrate; a first electrode layer formed on a top of the base layer; a light emitting layer formed on a top of the first electrode layer; and a second electrode layer formed on a top of the light emitting layer. The base layer includes a second protrusion pattern different from the first protrusion pattern on a top surface thereof.