Light Emitting Structure With Layered Protrusions for Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting devices face challenges in achieving high light extraction efficiency and reliability due to limitations in the design of protrusions and the presence of voids.
Innovation Solution
A light emitting device is designed with a substrate featuring a pattern of protrusions, each comprising a first layer formed integrally with the substrate and a second layer of different material, along with a light emitting stack that includes a first semiconductor layer, an active layer, and a second semiconductor layer. The protrusions are optimized in terms of diameter, pitch, and height ratio to enhance light extraction, and voids are strategically placed in the first semiconductor layer to improve light scattering and extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If protrusions are added to enhance light extraction efficiency, then light extraction efficiency is improved, but device complexity increases
Solution Approach 1:
The protrusion structure is segmented into two distinct layers: a first layer formed integrally with the substrate and a second layer made of different material. This segmentation allows each layer to serve specific functions - the first layer provides mechanical support and light scattering, while the second layer enhances light extraction through material properties, thereby improving light extraction efficiency without excessive complexity
Solution Approach 2:
The protrusions utilize composite material structure with a first layer (integrally formed with substrate) and a second layer (different material). This composite approach combines the advantages of both materials to achieve superior light extraction efficiency while maintaining structural integrity and managing complexity through functional differentiation
2Loss of energy
If voids are introduced to improve light scattering, then light extraction efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
Voids are strategically positioned in specific regions of the first semiconductor layer rather than uniformly distributed. This local quality approach concentrates light scattering effects in areas where they are most beneficial for extraction, while maintaining manufacturing feasibility by limiting void complexity to specific zones rather than requiring precise control throughout the entire structure
3Loss of energy
If protrusion diameter and pitch are optimized for light extraction, then light extraction efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent optimizes specific parameters including the ratio of protrusion diameter to pitch (set within 0.8 to 1.0) and the height ratio between first and second layers (set within 0.2 to 1.5). These parameter changes are designed to achieve optimal light extraction efficiency while remaining within manufacturable ranges, balancing performance optimization with manufacturing precision capabilities
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 proposed design significantly enhances light extraction efficiency and reliability by optimizing the protrusion pattern and incorporating voids, leading to improved light emission characteristics compared to conventional devices.
Implementation Method 1
voids are strategically placed in the first semiconductor layer to improve light scattering and extraction efficiency
Data Source
AI summary
A light emitting device includes a substrate; a pattern of a plurality of protrusions protruding from the substrate; a first semiconductor layer provided on the substrate; an active layer provided on the first semiconductor layer; and a second semiconductor layer provided on the active layer, in which each of the protrusions includes a first layer formed integrally with the substrate and protruding from an upper surface of the base substrate; and a second layer provided on the first layer and formed of a material different from that of the first layer.