LED Light Extraction via Refractive Index Dielectric Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optoelectronic devices with light-emitting diodes, such as microwires or nanowires, suffer from low extraction efficiency due to trapped or absorbed photons, and manufacturing methods are not cost-effective for industrial-scale production.
Innovation Solution
An optoelectronic device design featuring semiconductor microwires or nanowires with a partially transparent dielectric encapsulation layer having a refractive index between 1.6 and 1.8, and a specific distribution of light-emitting diodes on a semiconductor substrate to enhance light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If light-emitting diodes are arranged closely on the semiconductor substrate, then the device area is reduced and productivity is improved, but light extraction efficiency deteriorates due to light trapping and absorption by neighboring LEDs
Solution Approach 1:
A dielectric layer with refractive index between 1.6 and 1.8 is introduced as an intermediary medium between adjacent light-emitting diodes. This layer acts as an optical mediator that reduces light trapping and absorption between neighboring LEDs, enabling closer spacing while maintaining light extraction efficiency. The dielectric layer fills the spaces between LEDs and modifies the optical environment to prevent harmful light interactions.
2Loss of energy
If a dielectric layer with refractive index between 1.6 and 1.8 is added to improve light extraction efficiency, then light extraction efficiency is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent specifies a narrow refractive index range (1.6 to 1.8) for the dielectric layer to optimize light extraction efficiency. By controlling this critical optical parameter within specific bounds, the invention achieves improved light extraction while maintaining manufacturing feasibility. The thickness parameter is also controlled (250 nm to 50 μm) to balance performance and complexity.
3Loss of energy
If the dielectric layer thickness is increased to improve light extraction, then light extraction efficiency is improved, but manufacturing precision requirements and cost increase
Solution Approach 1:
The patent allows a wide thickness range (250 nm to 50 μm) for the dielectric layer, providing manufacturing flexibility. The lower bound (250 nm) ensures sufficient optical effect while the upper bound (50 μm) accommodates manufacturing variations. This partial specification approach balances performance requirements with manufacturing capabilities, avoiding overly stringent precision demands.
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 significantly increases the extraction efficiency of light-emitting diodes by reducing trapped and absorbed light, while enabling cost-effective industrial-scale manufacturing.
Implementation Method 1
a dielectric layer at least partially transparent covering the light-emitting diodes, the refractive index of the dielectric layer being between 1.6 and 1.8
Implementation Method 2
a fraction of the photons emitted within each light-emitting diode do not escape from the light-emitting diode
Data Source
Figure 1~6
Figure 7~10
Figure 11~20
AI summary
The invention relates to an optoelectronic device (5) comprising a semiconductor substrate (10) including a face (12), light-emitting diodes (LEDs) resting on the face and comprising wire, conical or frustoconical semiconductor elements (20) and a dielectric layer (34) at least partially transparent covering the light-emitting diodes, the refractive index of the dielectric layer being between 1.6 and 1.8.