Perovskite Luminescent Layer for Stable LCD Backlighting

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Solution Overview

Problem

The manufacturing of liquid crystal display (LCD) components with quantum dot-based backlights faces challenges due to incompatibilities between quantum dot materials, leading to degradation and reduced lifetime.

Innovation Solution

A light emitting component comprising a first blue light source, a second red light source, and a luminescent layer with perovskite green luminescent crystals embedded in a solid polymer composition, where the luminescent layer has a low haze to enhance stability and light conversion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If quantum dot particles are used to produce backlight colours, then the display component can achieve vibrant colours, but incompatibilities between quantum dot materials lead to degradation and reduced lifetime

Engineering Contradiction:

Improvebacklight colour qualityVSAvoidcomponent lifetime

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent changes the material parameter from traditional quantum dots to perovskite luminescent crystals, which have different chemical and physical properties. This parameter change resolves the incompatibility issue while maintaining the ability to produce vibrant backlight colours through controlled emission wavelengths.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure consisting of perovskite luminescent crystals embedded in a solid polymer matrix. This composite material approach allows the perovskite crystals to maintain their luminescent properties while the polymer matrix provides chemical stability and protection, preventing degradation and extending component lifetime.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If multiple quantum dot materials are embedded in the same material, then various backlight colours can be achieved, but chemical incompatibilities cause material degradation

Engineering Contradiction:

Improvebacklight colour rangeVSAvoidmaterial compatibility

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The solid polymer matrix acts as an intermediary medium that hosts multiple perovskite luminescent crystals with different emission characteristics. The polymer matrix provides a chemically compatible environment for all the perovskite crystals, preventing direct interaction between them and eliminating incompatibility issues while allowing versatile colour production.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes from using multiple traditional quantum dot materials to using perovskite luminescent crystals, which have superior chemical stability and compatibility. This parameter change in material composition allows multiple colour-emitting crystals to coexist in the same polymer matrix without degradation.

Inventive Principle:

Principle #35Parameter changes

3Illumination intensity

If the luminescent layer has high scattering, then light distribution can be improved, but multiplex scattering reduces light conversion efficiency

Engineering Contradiction:

Improvelight distributionVSAvoidlight conversion efficiency

Core Design Contradiction:

Illumination intensityVSLoss of energy

Solution Approach 1:

The patent optimizes the haze parameter of the luminescent layer to a specific range that balances light distribution and conversion efficiency. By controlling the haze parameter and using perovskite crystals with high photoluminescence quantum yield, the system achieves good light distribution while minimizing energy loss through excessive scattering.

Inventive Principle:

Principle #35Parameter 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

The solution improves the stability and brightness of the luminescent perovskite crystals, reducing multiplex scattering and increasing the light conversion factor, leading to a longer-lasting and more efficient LCD display.

Implementation Method 1

green luminescent crystals are perovskite crystals selected from compounds of formula (I)... Upon absorption of blue light emitted by the first light source, the luminescent crystals emit light of a wavelength in the green light spectrum

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS11803084B2Light emitting component and light emitting device

Publication Date: 2023.10.31 AVANTAMA AG

AI summary

A light emitting component comprising a first LED light source for emitting blue light, a second LED light source for emitting red light, and a luminescent layer (100) comprising a solid polymer composition and green luminescent crystals. The solid polymer composition comprises a polymer. The green luminescent crystals are perovskite crystals. The first and the second light source are directed to the luminescent layer. Upon absorption of the light emitted by the first light source, the luminescent crystals emit light of a wavelength in the green light spectrum.