Nitride Semiconductor Light-Emitting Element with Composite Quantum Wells

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Solution Overview

Problem

Semiconductor light-emitting elements face challenges in achieving uniform light-emitting wavelength, high color rendering properties, and high light-emitting intensity, particularly due to the complexity of manufacturing processes and the use of wavelength conversion components like phosphors, which can affect efficiency and crystallinity over time.

Innovation Solution

A semiconductor light-emitting element is designed with a nitride-based semiconductor structure that includes a quantum well layer with a base layer and barrier layers of varying compositions, featuring a mesh-like groove structure to enhance light emission across a wide visible spectrum without the need for phosphors, promoting high color rendering and intensity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a phosphor is used to convert blue light to yellow light to achieve white light emission, then color rendering properties are improved, but the manufacturing process complexity increases and the wavelength conversion efficiency deteriorates over time

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

Solution Approach 1:

The invention extracts and eliminates the phosphor component from the light-emitting device. Instead of using blue light + yellow phosphor to create white light, the patent directly generates white light through a single active layer with multiple quantum wells having different band gaps, thereby simplifying the device structure and manufacturing process while maintaining color rendering properties

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a composite quantum well structure within the active layer, where multiple quantum wells with different compositions (different band gaps) are integrated into a single semiconductor layer. This allows the device to emit multiple wavelengths simultaneously, producing white light directly without requiring external phosphor conversion

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If multiple active layers with different compositions are laminated to widen the light emission wavelength range, then color rendering properties are improved, but the manufacturing process complexity and crystallinity deterioration increase

Engineering Contradiction:
Improvelight emission wavelength rangeVSAvoidprocessing step complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The invention merges multiple light-emitting functions into a single active layer by integrating multiple quantum wells with different compositions within one continuous semiconductor layer. This eliminates the need for separate processing steps to laminate multiple active layers, simplifying manufacturing while achieving the same broad spectrum emission

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The active layer is segmented into multiple quantum wells with different compositions and thicknesses, each contributing to different wavelength ranges. This internal segmentation within a single layer achieves the wavelength diversity of multiple layers without the associated manufacturing complexity

Inventive Principle:
Principle #1Segmentation

3Illumination intensity

If a phosphor is added to the sealing resin to convert wavelength, then white light emission is achieved, but the light-emitting intensity deteriorates due to phosphor efficiency changes over time

Engineering Contradiction:
Improvewhite light emissionVSAvoidlight-emitting intensity stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The invention removes the phosphor from the sealing resin and eliminates the wavelength conversion step entirely. By generating all necessary wavelengths directly in the active layer through multiple quantum wells, the device achieves stable white light emission without the efficiency degradation associated with phosphor aging

Inventive Principle:
Principle #2Taking out (Extraction)

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 range and high light-emitting intensity with improved color rendering properties, overcoming the limitations of previous methods by maintaining crystallinity and simplifying the manufacturing process.

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

Data Source

PatentEP3217440B1Semiconductor light-emitting element
Publication Date: 2020.03.11 STANLEY ELECTRIC CO LTD
  • EP3217440B1 patent drawingFigure 1(a)~1(b)
  • EP3217440B1 patent drawingFigure 2(a)~2(c)
  • EP3217440B1 patent drawingFigure 3(a)~3(c)

AI summary

A semiconductor light-emitting element includes: a first semiconductor layer of a first conductivity type; a light-emitting functional layer that is formed on the first semiconductor layer and includes a light-emitting layer; and a second semiconductor layer that is formed on the light-emitting functional layer and is of a conductivity type opposite to the conductivity type of the first semiconductor layer. The light-emitting layer has: a base layer which has a composition subject to stress strain from the first semiconductor layer and has a plurality of base segments partitioned in a random net shape; and a quantum well structure layer formed on the base layer and composed of at least one quantum well layer and at least one barrier layer. The base layer has a composition of AlxGa1-xN (0 ≤ x ≤ 1). The at least one barrier layer has a composition of AlyGa1-yN (0 ≤ y < 1), and the composition x and the composition y satisfy a relation of x > y.