Semiconductor Light-Emitting Element With Segmented Quantum Wells

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Solution Overview

Problem

Existing semiconductor light-emitting elements face challenges in achieving uniform light-emitting wavelength, high color rendering properties, and high light-emitting intensity, particularly in manufacturing processes that require wavelength conversion members like phosphors, which can lead to inefficiencies and crystallinity deterioration.

Innovation Solution

A semiconductor light-emitting element is designed with a structure comprising n-type and p-type semiconductor layers, featuring first and second light-emitting layers with quantum well structures and barrier layers, where the base layers have different compositions and random net-shaped grooves, allowing for wide spectral coverage without the need for wavelength conversion members, enhancing crystallinity and light-emitting intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If phosphors are used for wavelength conversion to achieve white light emission, then color rendering properties are improved, but manufacturing complexity and process steps increase

Engineering Contradiction:
Improvecolor rendering propertiesVSAvoidmanufacturing process complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the phosphor wavelength conversion component from the LED structure. Instead of using phosphors to convert blue light to other wavelengths, the patent directly emits multiple wavelengths through a multi-quantum-well active layer, thereby simplifying the manufacturing process by removing the phosphor mixing step while maintaining color rendering properties

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The active layer is segmented into multiple quantum wells with different compositions (InGaN wells with varying In content) to emit different wavelengths simultaneously. This segmentation allows direct emission of multi-wavelength light without requiring external phosphor conversion, reducing manufacturing complexity while achieving good color rendering

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If phosphors are mixed into sealing resin to convert wavelength, then white light emission is achieved, but light-emitting intensity decreases due to wavelength conversion efficiency loss

Engineering Contradiction:
Improvewhite light emissionVSAvoidwavelength conversion efficiency
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The invention removes the phosphor wavelength conversion mechanism entirely. The active layer directly emits light across multiple wavelengths including blue, cyan, green, yellow-green, and red regions through quantum confined Stark effect and composition variations, eliminating energy loss associated with phosphor conversion and improving overall light-emitting intensity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the emission wavelength parameters by varying the composition of quantum wells within the active layer. Different InGaN well compositions emit at different wavelengths, and by controlling these parameters during growth, the device directly produces white light with high intensity without energy loss to phosphor conversion

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If multiple active layers with different compositions are laminated to widen light-emitting wavelength range, then color rendering is improved, but crystallinity deteriorates due to processing

Engineering Contradiction:
Improvelight-emitting wavelength rangeVSAvoidcrystallinity
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

Instead of laminating separate active layers, the invention segments the single active layer into multiple quantum wells with different compositions. This internal segmentation achieves wide wavelength coverage while maintaining a single continuous crystal structure, avoiding the crystallinity deterioration that would result from processing multiple separate layers

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges multiple quantum wells with different compositions into a single integrated active layer structure. This combining approach achieves the wavelength range of multiple layers while preserving crystallinity, as the quantum wells are grown epitaxially in a single continuous process rather than being processed as separate layers

Inventive Principle:
Principle #5Merging (Combining)

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 achieves a wide light-emitting wavelength band across the visible region with high color rendering properties and high light-emitting intensity, improving upon previous methods by eliminating the need for phosphors and maintaining crystallinity, thus providing a more efficient and stable light source.

Implementation Method 1

Emission of light by a semiconductor light-emitting element is induced when binding (recombination) of an electron and a hole injected into the element through electrodes occurs in the active layer of the element

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

first and second light-emitting layers 13A and 13B, each having a quantum well structure

Methodology Applied
Scientific EffectQuantum confinement: Potential Well

Data Source

PatentEP3217439B1Semiconductor light-emitting element
Publication Date: 2019.12.04 STANLEY ELECTRIC CO LTD
  • EP3217439B1 patent drawingFigure 1(a)~1(b)
  • EP3217439B1 patent drawingFigure 2~3
  • EP3217439B1 patent drawingFigure 4

AI summary

A semiconductor light-emitting element has a light-emitting functional layer including first and second light-emitting layers. The first light-emitting layer has: a first base layer that has a composition subject to stress strain from a first semiconductor layer and has a plurality of first base segments partitioned into a random net shape; a first quantum well structure layer that retains a segment shape of the first base segment and is formed on the first base layer; and a first barrier layer that has a flat surface flattened by embedding the first base layer and the first quantum well layer. The second light-emitting layer has: a second base layer that has a composition subject to stress strain from the first barrier layer and has a plurality of second base segments partitioned into a random net shape; a second quantum well structure layer that retains a segment shape of the second base segment and is formed on the second base layer; and a second barrier layer formed on the second quantum well layer.