Light-Modulated Quantum Dot Display With Aligned Polymer Matrix

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Solution Overview

Problem

Current quantum dot (QD) displays face limitations in achieving high color purity and wide color gamut due to non-uniform QD dispersion and the need for color filters, which result in transmittance loss and complex patterning processes.

Innovation Solution

The development of a light-modulated QD color display with uniformly dispersed QDs in an aligned polymer matrix, utilizing a light modulator to control emission intensity and eliminate the need for color filters, allowing for high color purity and wide color gamut without conventional color filter technology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If QDs are dispersed in a polymer matrix to simplify patterning, then ease of manufacture is improved, but uniformity of QD distribution deteriorates leading to aggregation

Engineering Contradiction:
Improvepatterning processVSAvoidQD distribution uniformity
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent introduces a surfactant as an intermediary substance between QDs and polymer matrix. The surfactant molecules adsorb onto QD surfaces and provide steric stabilization, preventing QD aggregation during polymerization. This mediator enables uniform QD dispersion in the polymer matrix without requiring complex patterning processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite material system consisting of QDs, surfactant, and polymer matrix. The surfactant-QD-polymer composite structure allows QDs to remain uniformly dispersed throughout the polymer matrix, combining the ease of polymer processing with uniform QD distribution for high-quality display performance.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If color filters are used to separate mixed colors into primary colors, then color separation is achieved, but transmittance loss increases and color purity is limited

Engineering Contradiction:
Improvecolor separationVSAvoidlight transmittance
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The patent extracts and eliminates the color filter component from the display structure. Instead of using color filters to separate mixed colors, the invention directly employs QDs with inherent narrow emission spectra to generate pure primary colors, removing the source of transmittance loss and color purity limitation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental approach to color generation by utilizing the wavelength-specific photoluminescence properties of QDs. By selecting QDs with different core materials and sizes, the system directly emits pure red, green, and blue light without requiring optical filtering, thereby maintaining high transmittance and color purity.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If QD patterns are made a few micrometers high to achieve sufficient emission intensity, then emission intensity is improved, but patterning complexity and process cost increase

Engineering Contradiction:
ImproveQD emission intensityVSAvoidpatterning process
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent changes the QD concentration parameter in the polymer matrix to control emission intensity. By adjusting the amount of QDs dispersed in the polymer, the system achieves sufficient emission intensity without requiring complex micrometer-scale patterning structures, simplifying the fabrication process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the polymer matrix serve multiple functions: it provides structural support, enables simple patterning through conventional lithography, and acts as a dispersion medium for uniform QD distribution. This multi-functionality eliminates the need for complex patterning processes while maintaining adequate emission intensity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 achieves uniform light emission across pixels, enabling high color purity and wide color gamut with analog grey levels, and simplifies manufacturing by eliminating the need for complex patterning and color filters, while being economically efficient for existing LCD manufacturers.

Implementation Method 1

The key concept of quantum dot (QD) color display technology is color representation with high color purity and wide gamut by photo-luminescence or electro-luminescence of QDs

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

matrix QD patterns emitting different colors are fabricated through uniform dispersion of QDs in aligned polymer matrix

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 3

a light modulator is utilized to control the emission intensity of QDs

Methodology Applied
Scientific EffectLight modulation:

Data Source

PatentEP3454113B1Light-modulated quantum dot color display and method for manufacturing the same
Publication Date: 2020.08.12 SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION
  • EP3454113B1 patent drawingFigure 1
  • EP3454113B1 patent drawingFigure 2A~2C
  • EP3454113B1 patent drawingFigure 3A~3B

AI summary

A light-modulated quantum dot (QD) color display according to an embodiment of the present disclosure includes a light source, a light modulator positioned above the light source to control the intensity of light generated from the light source, and a QD light-emitting element positioned above the light modulator and including a plurality of QD patterns having different emission properties in the visible light region by means of light intensity that has passed through the light modulator. According to an embodiment, the QD pattern is configured to accomplish light emission with uniformity and high color purity by uniform distribution of QDs in a matrix using aligned polymer, thereby simultaneously achieving the features of uniform emission of light over the entire pixel, intensity-tunability giving analog grey levels, and high color purity and wide color gamut without using a color filter beyond the limitation of existing QD color display technology.