Transmissive Conductive Layer for Semiconductor Light Emitting Device

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing semiconductor light emitting devices face challenges in improving light emitting efficiency and electrical reliability due to issues with the exposure of electrode layers during manufacturing processes, which can lead to short circuits and reduced product yield.

Innovation Solution

The implementation of a transmissive conductive layer between the compound semiconductor layer and the second electrode layer, along with an ohmic contact layer with patterns, enhances light emitting efficiency and electrical reliability by preventing exposure of the electrode layer during manufacturing and improving adhesive force between semiconductor layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional electrode layer structure is used, then manufacturing is simpler, but the electrode layer may be exposed during manufacturing processes leading to short circuits and reduced reliability

Engineering Contradiction:
Improveelectrical reliabilityVSAvoidlayer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a transmissive conductive layer as an intermediary between the compound semiconductor layer and the second electrode layer. This intermediate layer prevents direct exposure of the electrode layer during manufacturing processes while maintaining electrical conductivity and light transmission properties, thereby resolving the contradiction between reliability improvement and structural complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent divides the original single electrode layer structure into multiple segmented layers: a transmissive conductive layer and an ohmic contact layer with patterns. This segmentation allows each layer to perform specific functions - the transmissive conductive layer prevents exposure and maintains transparency, while the patterned ohmic contact layer provides electrical contact - thereby improving reliability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the electrode layer is made thinner to improve light transmission, then light emitting efficiency improves, but the electrode layer becomes more susceptible to exposure and short circuits

Engineering Contradiction:
Improvelight emitting efficiencyVSAvoidelectrical reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The transmissive conductive layer acts as a mediator that allows light to pass through effectively while providing a protective barrier that prevents the underlying electrode layer from being exposed during manufacturing. This resolves the contradiction by decoupling the light transmission function from the protective function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs composite material structures where the transmissive conductive layer and patterned ohmic contact layer work together. The composite structure combines materials with different properties - one optimized for light transmission and conductivity, another for electrical contact and pattern formation - achieving both high light emitting efficiency and electrical reliability.

Inventive Principle:
Principle #40Composite materials

3Reliability

If a patterned ohmic contact layer is added to improve current distribution, then electrical reliability improves, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrical reliabilityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The ohmic contact layer is created with a patterned structure where different regions have different properties. The patterned design concentrates ohmic contact material in specific locations where electrical contact is needed, while leaving other areas open or with different material composition. This local differentiation improves current distribution and electrical reliability while allowing for controlled manufacturing through standard photolithography and deposition techniques.

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 improves light emitting efficiency and electrical reliability by preventing short circuits and enhancing the distribution of electric current, thereby increasing the overall performance and yield of semiconductor light emitting devices.

Implementation Method 1

a transmissive conductive layer at an outer portion between a compound semiconductor layer and a second electrode layer

Methodology Applied
Scientific EffectLight transmission:

Implementation Method 2

an ohmic contact layer at an inner portion between a compound semiconductor layer and a second electrode layer

Methodology Applied
Scientific EffectOhmic contact:

Data Source

PatentEP2270880B1Semiconductor light emitting device
Publication Date: 2013.08.28 LG INNOTEK CO LTD
  • EP2270880B1 patent drawingFigure 1~2
  • EP2270880B1 patent drawingFigure 3~4
  • EP2270880B1 patent drawingFigure 5~6

AI summary

Disclosed is a semiconductor light emitting device. The semiconductor light emitting device comprises a first conductive semiconductor layer, an active layer under the first conductive semiconductor layer, a second conductive semiconductor layer under the active layer, a second electrode layer under the second conductive semiconductor layer, and a transmissive conductive layer at least one part between the second conductive semiconductor layer and the second electrode layer.