Semiconductor Light-Emitting Element With Random Net Base Segments

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Solution Overview

Problem

Semiconductor light-emitting elements face challenges in achieving uniform light-emitting wavelength, complex manufacturing processes, and reduced light-emission intensity, particularly when attempting to produce white light with high color rendering properties without using wavelength conversion materials like phosphors.

Innovation Solution

A semiconductor light-emitting element is designed with a first semiconductor layer, a light-emitting functional layer featuring a base layer with stress-strained segments in a random net shape and a quantum well light-emitting structure, allowing for broad spectral width and high light-emission intensity without the need for wavelength conversion members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a phosphor is used to convert blue light to achieve white light with high color rendering properties, then the color rendering properties are improved, but the manufacturing complexity increases and the light-emission intensity decreases due to wavelength conversion losses

Engineering Contradiction:
Improvecolor rendering propertiesVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the phosphor wavelength conversion component from the system. Instead of using a phosphor to convert blue light to achieve white light, the invention directly generates broad-spectrum white light through the quantum well light-emitting structure layer with multiple quantum wells having different indium compositions, thereby simplifying the manufacturing process and reducing wavelength conversion losses

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a composite quantum well structure with multiple InGaN quantum wells having different indium compositions (e.g., 15%, 20%, 25%, 30%) embedded in GaN barrier layers. This composite structure emits photons across a broad wavelength range simultaneously, directly producing white light with high color rendering properties without requiring phosphor conversion

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If etching is performed to form an uneven pattern on the semiconductor layer to broaden the light-emitting wavelength, then the wavelength bandwidth is improved, but the manufacturing complexity increases and the crystallinity degrades

Engineering Contradiction:
Improvewavelength bandwidthVSAvoidprocessing steps
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent incorporates the compositional variation needed for broad wavelength emission directly into the quantum well structure during the growth process itself. The multiple quantum wells with different indium compositions are formed in advance during MOCVD growth, eliminating the need for subsequent etching or pattern processing steps to create wavelength diversity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the compositional parameter (indium content) of the quantum well layers during growth to create multiple quantum wells with different emission wavelengths. By varying the indium composition from 15% to 30% across different quantum wells, the system achieves broad spectral width without mechanical processing or etching

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple quantum wells with different indium compositions are formed to emit light over a wide wavelength range, then the color rendering properties are improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecolor rendering propertiesVSAvoidcomposition uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent segments the quantum well structure into multiple discrete quantum wells, each with a specific indium composition (e.g., 15%, 20%, 25%, 30%). This segmentation allows each quantum well to be grown with controlled composition while collectively providing broad-spectrum emission. The segmentation approach makes the composition control more manageable compared to creating a single continuous composition gradient

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by giving each quantum well layer a distinct indium composition tailored to emit at specific wavelengths. Each quantum well has a localized compositional property that contributes to a specific portion of the spectrum, and the combination of these locally optimized wells achieves overall broad spectral coverage with high color rendering

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 enables high color rendering properties with a broad light-emitting wavelength band and high reproducibility, controlling the light-emitting wavelength bandwidth effectively, while maintaining high light-emission intensity and simplifying the manufacturing process by eliminating the need for phosphors.

Implementation Method 1

the base layer having a plurality of base segments that have a composition subject to stress strain from the first semiconductor layer

Methodology Applied
Scientific EffectStress strain:

Implementation Method 2

A semiconductor light-emitting element emits light by binding (recombination), in the active layer, of an electron and hole injected into the element through electrodes

Methodology Applied
Scientific EffectLight emission through electron-hole recombination: Electroluminescence

Data Source

PatentEP3276677B1Semiconductor light-emitting element
Publication Date: 2020.01.15 STANLEY ELECTRIC CO LTD
  • EP3276677B1 patent drawingFigure 1(a)~1(b)
  • EP3276677B1 patent drawingFigure 2~3
  • EP3276677B1 patent drawingFigure 4~5

AI summary

A semiconductor light-emitting element according to the present invention is a semiconductor light-emitting element including: a first semiconductor layer of a first conductivity type; a light-emitting functional layer formed on the first semiconductor layer; and a second semiconductor layer that is formed on the light-emitting functional layer and is of a second conductivity type opposite to that of the first semiconductor layer. The light-emitting functional layer has: a base layer formed on the first semiconductor layer, the base layer having a plurality of base segments that have a composition subject to stress strain from the first semiconductor layer and are formed in a random net shape, the base layer being doped with a dopant of the second conductivity type; and a quantum well light-emitting layer formed on the base layer.