LED Step Portion Lateral Electrode Light Extraction

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Solution Overview

Problem

Current light emitting diodes (LEDs) face challenges in optimizing light extraction efficiency and operational voltage, with existing structures not effectively addressing these issues for improved performance.

Innovation Solution

The proposed light emitting device features a second conductive semiconductor layer, an active layer, a first semiconductor layer with a step portion, and a lateral electrode on the step portion, which enhances light extraction efficiency and reduces operational voltage by improving current characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional LED structure is used, then the device is simple to manufacture, but light extraction efficiency is insufficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidlight extraction efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent introduces a step portion on the lateral side of the first semiconductor layer, creating a multi-level dimensional structure. This step portion forms a lateral surface that serves as an additional light extraction path, transitioning from a conventional planar structure to a stepped three-dimensional structure, thereby improving light extraction efficiency without significantly complicating the manufacturing process

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If the LED structure is optimized for brightness, then light extraction efficiency improves, but operational voltage increases

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidoperational voltage
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent segments the first semiconductor layer into different height levels by forming a step portion. This segmentation creates distinct regions: a first region at a higher level and a second region at a lower level. The step portion acts as an intermediate structure that facilitates both light extraction and current distribution, allowing the device to achieve improved light extraction efficiency while maintaining reasonable operational voltage through optimized current characteristics

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If a step portion is formed on the first semiconductor layer, then light extraction efficiency improves, but device complexity increases

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidstructural complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The step portion is formed locally on the lateral side of the first semiconductor layer rather than modifying the entire structure. This localized modification creates a specific geometric feature that enhances light extraction at critical interfaces without requiring complex changes throughout the entire LED structure, thus balancing improved light extraction efficiency with manageable device complexity

Inventive Principle:
Principle #3Local quality

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 configuration enhances light extraction efficiency and lowers operational voltage, resulting in improved performance and efficiency of the light emitting device.

Implementation Method 1

A light emitting diode (LED) is a semiconductor light emitting device that converts current into light

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2330643B1Light emitting device
Publication Date: 2016.03.09 LG INNOTEK CO LTD
  • EP2330643B1 patent drawingFigure 1
  • EP2330643B1 patent drawingFigure 2
  • EP2330643B1 patent drawingFigure 3~4

AI summary

Disclosed is a light emitting device including a second conductive semiconductor layer (150); an active layer (140) on the second conductive semiconductor layer; a first semiconductor layer (130) on the active layer, the first semiconductor layer having at least one lateral side with a step portion; and a lateral electrode (180) on the step portion formed at the at least one lateral side of the first semiconductor layer.