Stabilized Quantum Dot Composite via Ionic Metal Oxide Matrix

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Solution Overview

Problem

Down-converting nanoparticles like cadmium selenide and lead-halide perovskite quantum dots lack stability due to sensitivity to atmospheric oxygen and moisture, making them unsuitable for long-term use in LED lighting applications.

Innovation Solution

Embedding luminescent semiconducting nanoparticles in an ionic metal oxide matrix, such as potassium silicate, to create a stabilized quantum dot composite that acts as an oxygen and moisture barrier, enhancing their stability and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If quantum dots are used for down-conversion in LED lighting, then narrow photoluminescence emission line widths and tunable peak positions are achieved, but stability under operational conditions deteriorates due to sensitivity to oxygen and moisture

Engineering Contradiction:

Improveemission line widthVSAvoidstability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent embeds quantum dots within a silicate glass matrix to create a composite material structure. The silicate glass provides a protective environment that isolates the quantum dots from oxygen and moisture while maintaining their optical properties. This composite approach allows the quantum dots to retain their narrow emission line widths and tunable peak positions while achieving the stability required for commercial LED lighting applications.

Inventive Principle:

Principle #40Composite materials

2Measurement precision

If quantum dots are exposed to atmospheric oxygen and moisture, then narrow emission line widths are maintained, but luminous flux output and color point stability deteriorate

Engineering Contradiction:

Improveemission line widthVSAvoidsensitivity to oxygen and moisture

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The silicate glass matrix creates an inert protective environment around the quantum dots, effectively isolating them from atmospheric oxygen and moisture. The glass matrix acts as a barrier that prevents harmful interactions between the quantum dots and the external environment, thereby maintaining both the narrow emission line widths and the stability of luminous flux output and color point during LED operation.

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

3Reliability

If conventional inorganic phosphors are used, then stability and reliability are achieved, but narrow emission line widths and tunable peak positions are lost

Engineering Contradiction:

ImprovestabilityVSAvoidemission line width

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

By combining quantum dots with a silicate glass matrix, the patent creates a composite material that merges the advantages of both components. The quantum dots provide narrow emission line widths and tunable peak positions, while the silicate glass matrix provides the stability and reliability characteristic of conventional inorganic phosphors. This composite structure allows LED lighting to achieve both high color quality and long operational lifetime.

Inventive Principle:

Principle #40Composite materials

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 stabilized quantum dot composite exhibits significantly improved stability and reliability, maintaining luminous flux and color stability over extended operational periods, with emission wavelength shifts reduced by a factor of three and negligible luminous flux degradation.

Implementation Method 1

Embedding luminescent semiconducting nanoparticles in an ionic metal oxide matrix, such as potassium silicate, to create a stabilized quantum dot composite that acts as an oxygen and moisture barrier

Methodology Applied

Scientific EffectPhysical barrier:

Implementation Method 2

down-converting nanoparticles such as cadmium selenide quantum dots, indium phosphide quantum dots, and lead-halide perovskite quantum dots

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS10879433B2Stabilized quantum dot composite and method of making a stabilized quantum dot composite

Publication Date: 2020.12.29 CREELED INC

AI summary

A stabilized quantum dot composite includes a plurality of luminescent semiconducting nanoparticles embedded in a matrix comprising an ionic metal oxide. A method of making a stabilized quantum dot composite includes forming a mixture comprising a plurality of luminescent semiconducting nanoparticles dispersed in an aqueous solution comprising an ionic metal oxide. The mixture is dried to form a stabilized quantum dot composite comprising the plurality of luminescent semiconducting nanoparticles embedded in a matrix comprising the ionic metal oxide.