Substrate-Free Nitride Light Emitting Device with Insulated Holes

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Solution Overview

Problem

Existing light emitting devices using group III-V nitride semiconductors face challenges in light extraction efficiency due to the presence of a growth substrate, which can lead to defects and reduced performance.

Innovation Solution

A light emitting device package is developed without a growth substrate, featuring a first conductive type semiconductor layer with holes filled with an insulating material and a void space, enhancing light extraction efficiency through refractive index differences and improved structural design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a growth substrate is used during semiconductor layer fabrication, then manufacturing is enabled, but light extraction efficiency deteriorates due to defects and substrate interference

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidsubstrate defects
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent removes the growth substrate after the semiconductor layers are formed on it. The substrate serves only as a temporary platform during fabrication, then is extracted to eliminate its harmful effects on light extraction efficiency while retaining the benefit of having been able to manufacture the device structures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The semiconductor layers are formed on the substrate in advance before the substrate is removed. This preliminary action allows the complex multi-layer structures to be fabricated using standard substrate-based processes, then the substrate is removed afterward to improve performance.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the first conductive type semiconductor layer is made transparent, then light extraction is improved, but electrical conductivity deteriorates

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidelectrical conductivity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies local quality by making only the first conductive type semiconductor layer transparent while keeping other layers opaque. This localized transparency improvement enhances light extraction from the specific region where it is most beneficial, while maintaining the electrical conductivity properties of the overall device structure through other conductive layers and contacts.

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

The solution improves light extraction efficiency by modifying the refractive index critical angle and reducing defects associated with substrate removal, resulting in enhanced performance and efficiency of the light emitting device.

Implementation Method 1

enhancing light extraction efficiency through refractive index differences and improved structural design

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2357682B1Light emitting device, light emitting device package, and lighting system
Publication Date: 2016.11.23 LG INNOTEK CO LTD
  • EP2357682B1 patent drawingFigure 1~2
  • EP2357682B1 patent drawingFigure 3~5
  • EP2357682B1 patent drawingFigure 6

AI summary

Disclosed are a light emitting device and a light emitting device package. The light emitting device includes a first conductive type semiconductor layer including P-type dopants and having a plurality of holes, an electrode connected to the first conductive type semiconductor layer, an active layer under the first conductive type semiconductor layer, a second conductive type semiconductor layer under the active layer, and an electrode layer under the second conductive type semiconductor layer.