Nanoparticle Plasmon Energy Extraction for OLED Light Outcoupling

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Solution Overview

Problem

Existing organic light-emitting diodes (OLEDs) face challenges in efficiently outcoupling light due to internal quantum efficiency limitations and dim output, particularly when using plasmonic materials for enhancement layers.

Innovation Solution

Incorporation of nanopatch antennas composed of nanoparticles, deposited using inkjet printing, which non-radiatively couple to emitter materials, transferring excited state energy from the enhancement layer to surface plasmon polaritons and outcoupling it as photons through a carefully controlled deposition process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If plasmonic materials are used for enhancement layers in OLEDs, then light outcoupling efficiency is improved, but internal quantum efficiency limitations and dim output persist

Engineering Contradiction:

Improvelight outcoupling efficiencyVSAvoidinternal quantum efficiency

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent changes the physical and chemical parameters of the enhancement layer by using nanoparticles with specific sizes (20-200 nm), materials (silver, gold, aluminum), and arrangements (random, ordered, periodic). These parameter changes optimize the plasmonic resonance properties to improve light outcoupling efficiency while maintaining device stability and operational brightness.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material structures by combining plasmonic nanoparticles with organic emissive materials in the enhancement layer. This composite approach allows the plasmonic materials to enhance light outcoupling while the organic materials maintain the electroluminescent function, resolving the contradiction between improved illumination and maintained quantum efficiency.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If conventional fabrication methods are used, then manufacturing simplicity is maintained, but scalability for mass production is limited

Engineering Contradiction:

Improvefabrication simplicityVSAvoidscalability for mass production

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces conventional mechanical vacuum deposition methods with inkjet printing technology for fabricating the enhancement layer. This substitution enables precise control over nanoparticle placement, pattern formation, and material deposition, significantly improving scalability for mass production while maintaining ease of manufacture through a straightforward printing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Illumination intensity

If enhancement layers are added to improve light outcoupling, then illumination intensity increases, but device complexity increases

Engineering Contradiction:

Improveoutput brightnessVSAvoidstructure complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent segments the enhancement layer into discrete nanoparticle units rather than using continuous metal films. This segmentation allows for simplified fabrication through inkjet printing of individual particles, reduces material usage, and enables flexible device design while maintaining the plasmonic enhancement function for improved illumination intensity.

Inventive Principle:

Principle #1Segmentation

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

Enhances light outcoupling efficiency, stabilizes the OLED, and extends its operational brightness, achieving higher external quantum efficiencies comparable to conventional methods while allowing for scalable mass production.

Implementation Method 1

transferring excited state energy from the enhancement layer to surface plasmon polaritons and outcoupling it as photons

Methodology Applied

Scientific EffectSurface plasmon polaritons:

Implementation Method 2

the radiative decay of the surface plasmon polaritons is enhanced by the nanoparticles, which outcouple the plasmon energy as photons

Methodology Applied

Scientific EffectPlasmon outcoupling:

Data Source

PatentUS12426433B2Application of nanoparticles for plasmon energy extraction in organic devices

Publication Date: 2025.09.23 UNIVERSAL DISPLAY CORP

AI summary

Techniques are provided for depositing a monolayer of nanoparticles over an OLED or comparable device. In combination with an enhancement layer disposed within a threshold distance of an emissive layer of the OLED, the nanoparticles may be used to provide a nanopatch antenna or otherwise improve the performance of the OLED.