Micro LED Subpixel Structure With Nanorods and Red Color Conversion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current micro light-emitting display technologies face challenges in achieving high-resolution color images due to limitations in sub-pixel size reduction and efficient light emission, particularly in converting blue light to red light without compromising manufacturing processes and light efficiency.

Innovation Solution

The development of a micro light-emitting display apparatus with a rod semiconductor layer and nanorod semiconductor layers, featuring inclined surfaces and a color conversion layer to convert blue light into red light, along with a novel manufacturing method using potassium hydroxide or tetramethyl ammonium hydroxide for planarization, allowing for efficient green and red light emission without the need for a mesa structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional micro light-emitting structures are used, then manufacturing process is complex requiring mesa structures, but this increases device complexity and manufacturing difficulty

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidmesa structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent removes the mesa structure from the conventional LED design, extracting only the essential light-emitting components (active layer, electron transport layer, hole transport layer, and electrodes) while eliminating the complex lateral confinement structure. This simplifies the manufacturing process while maintaining light emission functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using the conventional approach of lateral light emission through mesa structures, the patent inverts the design by using vertical light emission through a planar structure with transparent electrodes, fundamentally changing the architectural approach to simplify manufacturing.

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If sub-pixel size is reduced for high-resolution displays, then display resolution improves, but light emission efficiency deteriorates

Engineering Contradiction:
Improvesub-pixel size controlVSAvoidlight emission efficiency
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent changes the structural parameters of the light-emitting layer, specifically using a vertical planar structure with transparent electrodes that allows efficient light extraction even from sub-100nm scale pixels. The parameter optimization includes layer thickness control and material selection to maintain high efficiency at reduced dimensions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures including transparent conductive oxides (ITO, IZO), organic light-emitting materials, and layered semiconductor structures that work synergistically to maintain high light emission efficiency in miniaturized sub-pixels through enhanced charge transport and light extraction.

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If blue light is converted to red light for color display, then color image capability improves, but light efficiency is compromised

Engineering Contradiction:
Improvecolor emission capabilityVSAvoidlight conversion efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent implements color emission by directly designing active layers with different compositions to emit different colors (blue, green, red) rather than using wavelength conversion. This eliminates energy loss associated with phosphor conversion while achieving full-color display capability through compositional control of the light-emitting materials.

Inventive Principle:
Principle #32Color changes

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 approach enables the production of high-resolution color images by enhancing light efficiency and simplifying the manufacturing process, reducing sub-pixel size limitations and improving contrast, while maintaining high luminous efficiency and defect reduction.

Implementation Method 1

a color conversion layer configured to convert the blue light emitted from the fourth light-emitting unit into red light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a first active layer configured to emit blue light, a rod semiconductor layer provided on the first active layer, a second active layer provided on the rod semiconductor layer and configured to emit green light

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3979325B1Micro light-emitting display apparatus and method of manufacturing the same
Publication Date: 2024.11.13 SAMSUNG ELECTRONICS CO LTD
  • EP3979325B1 patent drawingFigure 1A~1B
  • EP3979325B1 patent drawingFigure 2
  • EP3979325B1 patent drawingFigure 3

AI summary

A micro light-emitting display apparatus and a method of manufacturing the same are disclosed The micro light-emitting display apparatus includes a first semiconductor layer, an isolation structure provided on the first semiconductor layer and configured to define a plurality of sub-pixels each configured to emit light, a first light-emitting unit including a first active layer provided in a first sub-pixel among the plurality of sub-pixels, and a second semiconductor layer provided on the first active layer, and a second light-emitting unit including a rod semiconductor layer provided in a second sub-pixel among the plurality of sub-pixels, a second active layer provided on the rod semiconductor layer, and a third semiconductor layer provided on the second active layer. The first active layer is configured to emit blue light and the second active layer is configured to emit green light.